SpaceX Tests Raptor Engine

File: 151 KB, 2048x1364, CtQbdtJVIAA7HCC.jpg orig.jpg%20orig.jpg [View same] [iqdb] [saucenao] [google]

SpaceX Tests Raptor Engine Anonymous Mon Sep 26 03:27:55 2016 No.8371390 [Reply] [Original]

"SpaceX propulsion just achieved first firing of the Raptor interplanetary transport engine"
>https://twitter.com/elonmusk/status/780275236922994688/photo/1

>3MN of thrust
>382 specific impulse
>30 MPa chamber pressure (highest ever for production engine
Jesus Fucking Christ.

Anonymous Mon Sep 26 03:30:47 2016 No.8371394

>>8371390

It's chemical fueled. Yawn. We have been building the exact same devices for sixty years, and it is just as inadequate for 'interplanetary transport' as it always has been.

We need 3000-12,000 seconds of Isp (or more) and meganewtons of thrust to make REAL spaceships.

Unfortunately, that requires nuclear pulse propulsion or Fucking Magic.

>>	Anonymous Mon Sep 26 03:34:27 2016 No.8371396 File: 7 KB, 130x179, 1423871382880.jpg [View same] [iqdb] [saucenao] [google] >>8371394 >why aren't we using thing that doesn't exist yet instead?

>>	Anonymous Mon Sep 26 03:36:00 2016 No.8371399 >>8371396 >>why aren't we using thing that doesn't exist yet instead? Because we're afraid of it. Not because it doesn't exist. https://en.wikipedia.org/wiki/Nuclear_pulse_propulsion

>>	Anonymous Mon Sep 26 03:37:43 2016 No.8371403 >>8371399 Nuclear pulse will never be cost effective You're far better off investing in nuclear electric or fusion pulse for high isp alternatives.

Anonymous Mon Sep 26 03:49:42 2016 No.8371417

>>8371403
>You're far better off investing in nuclear electric or fusion pulse for high isp alternatives.

NO.

High ISP is only half the equation. For a practical transport system, you need high ISP combined with high thrust.

High specific impulse demands extremely high power levels per unit of momentum. Thus, you need terawatt power levels as the bare minimum starting levels.

Thus, nuclear pulse.

Your economics argument is so nonsensical I'm ignoring it.

>>	Anonymous Mon Sep 26 03:53:25 2016 No.8371422 >>8371417 >Your economics argument is so nonsensical I'm ignoring it. Oh, making nukes is cheap now?

Anonymous Mon Sep 26 04:01:37 2016 No.8371429

>>8371422
Why do you lie? Yes nukes are cheap, certainly the cheapest part of any nuclear program is making the nukes!

Any NPPP vessel won't be using expensive fusion devices, merely "cheap as you can get" fission devices.

What is the cost of an optimized nuclear pulse unit assuming mass production/automization/no regulatory jewry? Obviously impossible to say, but I'd wager extremely low.

>>	Anonymous Mon Sep 26 04:04:30 2016 No.8371435 >>8371429 I'm not sure if it's even worth responding to someone who is patently retarded.

Anonymous Mon Sep 26 04:12:49 2016 No.8371447

>>8371435
Uranium is cheap
Uranium is availible in huge quantities in the earths surface
Fission reactions offer 1 million times the energy density of chemical reactions.

If an NPP vehicle is built, just like with nuclear reactors, the production of the fissile material would be just a tiny % of the total cost.

>>	Anonymous Mon Sep 26 04:18:39 2016 No.8371448 >>8371447 Isolation of U235 is not cheap, and likely never will be. >but da ore is cheap Kill yourself my man

>>	Anonymous Mon Sep 26 04:30:13 2016 No.8371464 >>8371448 U-238 turns into Pu-239

>>	Anonymous Mon Sep 26 06:35:11 2016 No.8371535 >>8371390 >>8370095

Anonymous Mon Sep 26 10:47:02 2016 No.8371800

>>8371464
Breeding Pu-239 is generally accepted to be several times more expensive than isotopically separating U-235.

And you're filling a thread about exciting real news with tangential crackpot garbage about how nice it would be to live in a world where nukes were free and nobody minded if you set them off.

>>	Anonymous Mon Sep 26 10:52:31 2016 No.8371810 >>8371394 >Fucking Magic Exactly. Call us when you invvent magic.

Anonymous Mon Sep 26 10:55:51 2016 No.8371818

This test only involved a small-scale model, and the engine itself has nothing revolutionary, the only new thing being that it's fueled by methane, a fuel with inferior performances than hydrogen. As for the "it will be yuuuuuge part", making large engines is never usually a problem, paying for them is, so I'll take this seriously when 70% of SpaceX's earning won't come directly or indirectly from the government.

Another non-event brought to you by Elon Entertainment, Inc.

>>	Anonymous Mon Sep 26 10:56:04 2016 No.8371819 >>8371429 >nukes are so expensive, the US could never afford to make tens of thousands of them you are dumb

>>	Anonymous Mon Sep 26 11:11:12 2016 No.8371833 >>8371390 This gets my juices flowing.

>>	Anonymous Mon Sep 26 11:16:23 2016 No.8371843 >>8371394 solar sails for infinity ISP

Anonymous Mon Sep 26 11:21:28 2016 No.8371847

>>8371818
>This test only involved a small-scale model,
Full-scale engine.

>and the engine itself has nothing revolutionary,
Highest combustion chamber pressure ever achieved (thanks to the multistage full-flow staged combustion turbopumps). First fluid-bearing (i.e. non-wearing, for long-life reusability) turbopumps on a large-scale rocket engine. Fast-response throttleability for flyback landing. Highest specific impulse achieved with a hydrocarbon fuel.

>the only new thing being that it's fueled by methane, a fuel with inferior performances than hydrogen.
A fuel with inferior specific impulse, but superior density impulse and thrust-to-weight, along with handling advantages such as being liquid at the same temperatures as oxygen, making space storage much more feasible.

This is probably the first rocket engine suitable for airliner-like, gas-and-go reusability, and the first rocket engine suitable for use after long trips in space without severely reduced performance figures.

Anonymous Mon Sep 26 11:27:04 2016 No.8371853

>>8371819
>From 1940-1996, the United States spent a minimum of $5.5 trillion on its nuclear weapons program.[2] The lack of data for some programs and the difficulty of segregating costs for programs that had both nuclear and conventional roles mean that in all likelihood the actual figure is higher. This figure does not include $320 billion in estimated future-year costs for storing and disposing of more than five decades' worth of accumulated toxic and radioactive wastes and $20 billion for dismantling nuclear weapons systems and disposing of surplus nuclear materials. When those amounts are factored in, the total incurred costs of the U.S. nuclear weapons program exceed $5.8 trillion.[3]
>...
>The amount spent through 1996—$5.5 trillion—was 29 percent of all military spending from 1940 through 1996 ($18.7 trillion).
>...
>[2] Except where noted, all cost figures in this paper have been adjusted for inflation and are expressed as constant fiscal 1996 dollars.
>...
>[3] A subsequent estimate based on Atomic Audit and using its methodology, found that costs through 2005 were $7.5 trillion in adjusted 2005 dollars.

-- http://www.nti.org/analysis/articles/costs-us-nuclear-weapons/
>Seen in the year-by-year breakdown listed below, the total amounts (in nominal dollars) that NASA has been budgeted from 1958 to 2011 amounts to $526.178 billion
>...
>...when measured in real terms (adjusted for inflation), the figure is $790.0 billion

-- https://en.wikipedia.org/wiki/Budget_of_NASA

>>	Anonymous Mon Sep 26 11:42:09 2016 No.8371866 >>8371390 Nice would-be specs which have nothing to do with the prototype tested.

>>	Anonymous Mon Sep 26 11:43:00 2016 No.8371867 >>8371818 Im sure you have the numbers that shows that all other launch providers dont get most of their capital from government-related launches.....

>>	Anonymous Mon Sep 26 11:46:21 2016 No.8371871 >>8371847 Ah yes, the old reusability meme, number one obstacle that prevented us from going to Mars ever, and the claim that these very specifics internal details are any relevant. Had a good lol, m8.

Anonymous Mon Sep 26 11:55:38 2016 No.8371887

>>8371871
>the old reusability meme, number one obstacle that prevented us from going to Mars ever
Well, yeah. Number one obstacle for doing anything manned in space is high orbital launch costs. The main reason for high orbital launch costs is the lack of efficient reusability.

>>	Anonymous Mon Sep 26 12:01:26 2016 No.8371903 >>8371867 Arianespace gets annual subsidies in the vicinity of €100M. Their annual revenues are around €1.4B, about 90% of that are commercial launches. So that's about 8% government financed.

>>	Anonymous Mon Sep 26 12:03:52 2016 No.8371906 >>8371903 Well, that sounds like a heaping load of bullshit. What your source?

>>	Anonymous Mon Sep 26 12:04:10 2016 No.8371908 >>8371903 *17%

Anonymous Mon Sep 26 12:32:58 2016 No.8371976

>>8371906
>>8371903
I'm guessing this:
>Arianespace gets annual subsidies in the vicinity of €100M.
...is direct, open, specific, as-labelled operating subsidies for commercial launches of Ariane 5 alone.

Not counting subsidies hidden as government launches paying higher prices, or vehicle development (which is largely funded up-front by government, at a lavish standard and with no expectation of repayment), land giveaways, services provided free of charge, money provided as "investment", non-Arianespace-specific subsidy programs, etc.

Anonymous Mon Sep 26 12:34:32 2016 No.8371981

>>8371906
Unlike SpaceX Arianespace publish financial statements. Their revenues are no secret.
The ESA subsidies are also well known. They vary from year to year. Sometimes Arianespace makes a profit then they get nothing. Sometimes they don't then they get subsidy. The €100M figure is an average and well known in the industry. The rest is primary school level math.

Exemplary subsidy numbers can be found here:
http://seradata.com/SSI/2015/05/arianespace-revenues-up-41-and-it-even-makes-a-profit-after-its-usual-cash-injection/
http://www.parabolicarc.com/2012/04/25/arianespace-makes-profit-with-large-esa-subsidy/

Anonymous Mon Sep 26 12:48:58 2016 No.8372018

>>8371976
>subsidies hidden as government launches paying higher prices
I already accounted for that in the 17% figure by taking 10% off the revenues and adding it to subisidies. Also, unlike in the US, European government launches aren't mandated by law to be launched only by a European LSP. The German DoD, e.g., will launch recon sats with SpaceX. So Arianespace wins government contracts by competitive bidding.

>or vehicle development (which is largely funded up-front by government, at a lavish standard and with no expectation of repayment)
Arianespace buys the launch vehicles. So what's in ESA's budget as expenditure for launcher development comes via Airbus Safran Launchers as costs to Arianespace. And the costs of the Soyuz rocket come as revenue for the manufacturers of the Soyuz rocket. So that's completely accounted for.

>land giveaways
what?

>services provided free of charge
name them

>money provided as "investment"
what do you mean?

>non-Arianespace-specific subsidy programs
Which should by accounted to Arianespace's costs why exactly?

Anonymous Mon Sep 26 13:17:27 2016 No.8372065

>>8371981
>Unlike SpaceX Arianespace publish financial statements. Their revenues are no secret.
But they are nonsense numbers from la la land. Arianespace is owned by its subsidizing governments and by its suppliers, which are also subsidized. As a corporate entity, its expenses are the same as its profits: payments to its owners.

You would expect it to operate on a near-zero, but non-negative "profit" basis until right before it was shut down.

>>	Anonymous Mon Sep 26 13:21:53 2016 No.8372076 >>8372065 >You would expect it to operate on a near-zero And that's exactly what it does. Arianespace gets these ~€100M subsidies so that it breaks even. No LSP can survive without government money. But Arianespace is by far the least subsidized.

Anonymous Mon Sep 26 13:36:30 2016 No.8372101

>>8372076
>Arianespace is by far the least subsidized.
You're talking about Arianespace the corporate legal entity, not Arianespace, the overall system that produces and operates launch vehicles.

The corporate entity buys heavily-subsidized vehicles from other parts of the system, and rents heavily-subsidized facilities, and is subsidized directly itself.

Reasoning from the direct subsidies alone leads to vacuous arguments.

How would your argument stand if Arianespace got its vehicles provided to it for free? Would you not count these free vehicles as a subsidy? Why is it different if the vehicles provided to it are just very heavily subsidized?

Anonymous Mon Sep 26 13:47:56 2016 No.8372127

>>8371853
>Of the $5.8 trillion, just seven percent ($409 billion) was spent on developing, testing, and building the actual bombs and warheads.

IT SAYS IT RIGHT IN UR FUCKING ARTICLE
Just 7 percent was for the bombs! And thats starting from scratch, tens of thousands of fancy military nukes that have to be able to sit around for decades, be durable, fission/fusion/fission bombs etc.

>>	Anonymous Mon Sep 26 13:53:50 2016 No.8372141 >>8372127 >nukes alone make a spaceship that uses nukes retard, a nuclear powered spaceship will cost at least as much as nukes AND their delivery systems.

>>	Anonymous Mon Sep 26 13:55:08 2016 No.8372144 >>8372141 energy in general

>>	Anonymous Mon Sep 26 13:55:47 2016 No.8372149 >>8372101 >Number of employees 321 Thats really all you gotta see about arianespace to know whats going on there. They are just the commercial entity to sell launches to the private sector.

Anonymous Mon Sep 26 13:59:21 2016 No.8372159

>>8372141
Just by going from public to private, you achieve cost reductions of over 10 fold.
Then add on automation, the use of computers, 3d modelling in design, etc

You would have to be insane to think building NPPP vehicles would cost hundreds of billions.

Anonymous Mon Sep 26 14:27:43 2016 No.8372241

>>8372159
You would have to be insane to think that NPP would just work, without a lengthy development program and a huge number of open-air tests of very dirty low-yield fission bombs, or that providing adequate security for a private system using so many bombs is even feasible, let alone cost-effective.

Compare: a single-use NPP vehicle, which takes 1500 tons payload to Earth escape, vs. a fully-reusable chemical rocket which runs on LOX/LNG and takes 100 tons to LEO (and therefore needs maybe 50 launches to assemble a 1500-ton-payload departure).

50 loads of LOX/LNG, even for something triple the size of Saturn V, will cost far less than 800 nuclear bombs, and the development of the highly-reusable chemical rocket will be far simpler, and more incrementally beneficial, than that of the NPP vehicle.

I do think it's worth developing advanced nuclear propulsion, but not for use on and around Earth.

Anonymous Mon Sep 26 14:29:01 2016 No.8372246

>>8372101
>The corporate entity buys heavily-subsidized vehicles from other parts of the system
prove it

>rents heavily-subsidized facilities
As does every LSP. It's not like 6 different active launch complexes plus 30 inactive plus 3 pending reactivation in Florida and 5 different active launch complexes plus 35 inactive in Vandenberg are any cheaper to operate and maintain or even remotely as cheap for the US taxpayer as the the 3 active launch pads (just pads, not complexes), 3 inactive and 1 under construction in Centre Spatial Guyanais are for European taxpayers.

>is subsidized directly itself.
Yeah, by ~€100M annually. Which is peanuts compared to what the US, China, Russia, India or Japan do.

Anonymous Mon Sep 26 14:31:28 2016 No.8372254

>>8372159
>Just by going from public to private, you achieve cost reductions of over 10 fold.
>Then add on automation, the use of computers, 3d modelling in design, etc
That's not an argument supporting nuclear over chemical. If anything the reduction might be enough so that the huge capital costs make chemical feasible for private entrepreneurs but still leave nuclear as too expensive.

>>	Anonymous Mon Sep 26 14:32:46 2016 No.8372258 >>8371394 >>>/x/tard

Anonymous Mon Sep 26 14:37:34 2016 No.8372269

>>8372246
>>The corporate entity buys heavily-subsidized vehicles from other parts of the system
>prove it

>I am not interested in conversing reasonably. I view this as a contest and intend to proceed adversarially, despite the lack of a referee or impartial judge, and position myself as both judge and opponent.

Anonymous Mon Sep 26 14:39:15 2016 No.8372271

>>8372149
They do integration and launch, too. And they do it very well. For example the Soyuz never failed when operated by Arianespace. It did though when operated by Russia. Arianespace buys its launch vehicles. These costs are being subtracted from their revenues. Bottom line they lack on average about ~€100M annually to break even, which is why they get that from ESA.

>>	Anonymous Mon Sep 26 14:41:36 2016 No.8372278 >>8371390 Sounds unrealistic, unless there are more investment, a big amount. This going nowhere.

>>	Anonymous Mon Sep 26 14:41:50 2016 No.8372281 >>8372269 >make unsourced claim >refuse to provide proof when asked for >claim other side isn't interested in reasonable conversation instead Bad form, Peter. Bad form, indeed.

>>	Anonymous Mon Sep 26 14:43:24 2016 No.8372285 File: 35 KB, 631x643, 12 years a slave.png [View same] [iqdb] [saucenao] [google] >>8372241 In 20 years the solar system could be ours.

>>	Anonymous Mon Sep 26 14:43:28 2016 No.8372286 File: 124 KB, 770x459, image.png [View same] [iqdb] [saucenao] [google] >>8371800 >Violating the NAP by not letting me own recreational nukes

Anonymous Mon Sep 26 14:44:29 2016 No.8372292

>>8372281
That the consolidated European aerospace industry (Airbus), and the production of launch vehicles in particular, is heavily subsidized and only semi-private at most, is common knowledge and not disputed by reasonable people.

Go be garbage somewhere else.

>>	Anonymous Mon Sep 26 14:44:54 2016 No.8372293 File: 35 KB, 954x738, ISP.png [View same] [iqdb] [saucenao] [google] >>8371394 This

>>	Anonymous Mon Sep 26 14:45:34 2016 No.8372294 >>8372285 Do you remember what the cost and schedule predictions of the space shuttle looked like before it actually got built?

>>	Anonymous Mon Sep 26 14:45:59 2016 No.8372295 File: 203 KB, 800x969, Enceladus_1970.jpg [View same] [iqdb] [saucenao] [google]

>>	Anonymous Mon Sep 26 14:47:08 2016 No.8372298 File: 104 KB, 664x574, Cost per pulse unit.png [View same] [iqdb] [saucenao] [google]

>>	Anonymous Mon Sep 26 14:49:08 2016 No.8372308 File: 362 KB, 1280x1024, Orion_on_pad_5.jpg [View same] [iqdb] [saucenao] [google] >>8372294 The shuttle was a job project from the start. At least it got the russians to abandon their moon program.

Anonymous Mon Sep 26 14:50:55 2016 No.8372312

>>8372241
> a single-use NPP vehicle
Why is it single use, when with it's massive Isp & thrust its taking that payload to mars then returning? And ofc a vehicle that small would just be the first test vehicle, you can scale it up significantly without increasing the fissile material needed.

>(and therefore needs maybe 50 launches to assemble a 1500-ton-payload departure).
Building a vehicle in one piece in a ground based shipyard will always be vastly easier and cheaper than building it in orbit.

>and a huge number of open-air tests of very dirty low-yield fission bombs
These nukes would be very clean, using a minimum of plutonium, as they would be optimized for cost, not for size/yield.
The dirtiest part of nukes have always been the fallout from dirt kicked up.

Sure yes I agree that for the foreseable future there won't be any nuclear pulse vehicle made, and the private sector will never be allowed to engage in the regulatory free work needed to make it cost competitive/superior to conventional vehicles.
But a man can dream can't he?

>>	Anonymous Mon Sep 26 14:51:49 2016 No.8372315 >>8371394 Have you heard about Nuclear salt-water rocket.

>>	Anonymous Mon Sep 26 14:59:07 2016 No.8372346 File: 53 KB, 600x336, 1473262625354.jpg [View same] [iqdb] [saucenao] [google] >>8371390 it really doesn't matter what "engine" they use at this point, the problem of this shitpiece always been the fuel tanks

>>	Anonymous Mon Sep 26 14:59:12 2016 No.8372347 >>8372292 still waiting for proof of the original claim

>>	Anonymous Mon Sep 26 15:03:50 2016 No.8372362 >>8371448 You dont need to enrich it fully.Ten percent ot tweenty percent enriched uranium gives you the solar system

>>	Anonymous Mon Sep 26 15:06:42 2016 No.8372374 >>8371847 This guys know stuff.Another advantage is methanes ability to self pressure the tanks.So we ditch the helium bottles.

Anonymous Mon Sep 26 15:07:33 2016 No.8372377

>>8371887
>Number one obstacle for doing anything manned in space is high orbital launch costs
That's nowhere near true. Payloads usually cost between 5 and 10 times the cost of the launch. This is especially true for scientific/human spaceflight payloads. Communication sats usually have a standardised bus and quasi-standardised equipment (communication, propulsion, etc), while you have to develop everything from zero otherwise. Development of all subsystems and testing is what costs, by far, the most money and demand the most man-hours.

So, no, cost of launcher is really not the main worry for a manned mars mission. All the musk is ever going to achieve is making life slightly more comfortable for boring telecom multinationals such as SES or Intelsat thanks to a moderate discount on GTO launches.

But that wouldn't sell very well on twitter

Anonymous Mon Sep 26 15:16:33 2016 No.8372395

>>8372347
Not him, but SpaceX claims to have a backlog of 70 launches for 10 billion $. That's about... 146 millions $ per flight. Very far for the 70 millions or so that are advertised. How is that possible? No rocket science, the government buys spacex launches at a monstruous prize so that spacex can stay afloat on the commercial market. It's indirect subsidies. Then you have direct subsidies, like US states giving elon free money so he builds his factories there.

And despite all that, they barely manage to make any profit. At their current commercial prizes, SpaceX wouldn't last a month without subsidies.

>>	Anonymous Mon Sep 26 15:21:04 2016 No.8372410 >>8372395 >prizes (prices* of course)

>>	Anonymous Mon Sep 26 15:24:23 2016 No.8372416 >>8372315 Nigga, that's dumb. The water is going to put out the flame.

>>	Anonymous Mon Sep 26 15:28:33 2016 No.8372426 >>8372416 Nope salt water has ten percent enruched Uranium and that undergoes fission and kaboom just near the nozzle.Water evaporates and is so fast that it leaves the solar system forever.Now you got other cycle and dont do this at home.

Anonymous Mon Sep 26 15:28:37 2016 No.8372427

>>8372312
>Why is it single use, when with it's massive Isp & thrust its taking that payload to mars then returning?
If it returns, then it has to blow up that many more bombs in and around Earth's atmosphere.

>Building a vehicle in one piece in a ground based shipyard will always be vastly easier and cheaper than building it in orbit.
Why? It's way easier to move big things around in zero-g.

And it's not "building", it's "assembling". Docking. Snapping together.

>These nukes would be very clean, using a minimum of plutonium, as they would be optimized for cost, not for size/yield.
No, they would be very dirty, because they're designed for low yield.

You seem to have some very confused ideas about nukes. It's the primary stage that's the most expensive, made of plutonium, tritium, and high-precision explosives. The fusion stage is made of cheap stuff like enriched uranium and lithium deuteride, and it's set off by the overwhelming energy of the primary, so precise construction isn't nearly as important.

Plutonium-239 is itself a very nasty radioisotope you don't want to release, so the first requirement for having a clean nuke is lots of fusion generating lots of neutrons to make sure the Pu-239 all undergoes fission (although fission fragments are no picnic either, so you want fission to provide as little energy as possible). The dirtiest bombs are generally the smallest-yield ones, since they can't go below the minimum size of a primary or make much use of fusion, and achieve small yield by being inefficient (having only a small amount of their plutonium undergo fission).

Anonymous Mon Sep 26 15:31:56 2016 No.8372438

>>8372395
I know. In reality NASA is SpaceX's most important "customer" by far.
The thing is Arianespace is far less dependent on government launches. They're the ones most aligned towards the commercial launch market, precisely because European governments could never spend that much money on space. Plus European government payloads are not restricted to use European launchers only. They've used European, American, Russian and Indian launchers so far, which forces Arianespace to remain competitive. And they are and have been for decades. With a 50% share of the commercial market, which they consitently hold, they're market leader.

Anonymous Mon Sep 26 15:33:23 2016 No.8372443

>>8372377
>>Number one obstacle for doing anything manned in space is high orbital launch costs
>That's nowhere near true. Payloads usually cost between 5 and 10 times the cost of the launch.
First of all, that's an exaggeration. Secondly, payloads only cost so much because launch costs so much.

To suggest that you could lower launch costs to thousands instead of millions of dollars, and increase launch availability from "order it two years in advance and pray" to "order it when they payload's ready, launch it next week", and people would still only launch billion-dollar science projects is absurd.

People would launch cheaply-built stuff into space to test it. They'd set up assembly lines, and launch thousands of copies of things, instead of running a big R&D project just to build one thing.

>>	Anonymous Mon Sep 26 15:41:50 2016 No.8372467 >>8372427 >then it has to blow up that many more bombs in and around Earth's atmosphere. No we have aerobraking for the return, so it would need a small fraction of the bombs, and this pusher plate probably makes a good heatshield too.

Anonymous Mon Sep 26 15:43:56 2016 No.8372474

>>8372443
>lower launch costs to thousands instead of millions of dollars, and increase launch availability from "order it two years in advance and pray" to "order it when they payload's ready, launch it next week",
To claim that this will happen with any chemical rocket is even more absurd tb'h

Medium-term it's a 30% discount *at most*. Sure, this is totally going to make testing irrelevant, and development of highly-critical subsystems such as life support for a manned mission will magically go down as well. Insurance will be made useless, and while we're at it, let's even envision that post-launch costs (which can be 50% of the mission's cost) will decrease too. Why not, the world of Musk fanboys has so little to do with reality anyway.

Launch costs aren't what is preventing us from going to mars.

Anonymous Mon Sep 26 15:47:30 2016 No.8372483

>>8372474
>Medium-term it's a 30% discount *at most*.
>Medium-term the cost savings on a fully-reusable rocket is the 30% discount negotiated on a launch already coming in November for a rocket partway through its incremental development from expendable to partially-reusable *at most*.
Jesus Christ.

Anonymous Mon Sep 26 15:47:35 2016 No.8372486

>>8372443
>First of all, that's an exaggeration. Secondly, payloads only cost so much because launch costs so much.
Not that anon, but it's not an exaggeration. And no, payloads don't cost that much because of launch costs but because they have to work reliably for many years without any maintenance at all in a very harsh environment which can't be fully replicated for testing on Earth.

Small series production is already being done with comsats to reduce payload cost down to about 2-3 times the launch costs. And that's just manufacture. Operating it over its 15+ years lifetime costs additionally.

The debate is much older than 4chan. Launch costs will only come down with expanded production of launchers. But this will only be feasible with an expanded market for payloads. It's demand driven not supply driven. And it grows rather slowly. If you want space to be more accessible by reduced launch costs the best thing you can do is invest in commercial satellite operations to increase volume there, not launchers as these would follow increased demand automatically. But first there has to be the demand.

Anonymous Mon Sep 26 15:50:10 2016 No.8372496

>>8372486
>payloads don't cost that much because of launch costs but because they have to work reliably for many years (because of launch costs) without any maintenance at all (because of launch costs) in a very harsh environment which can't be fully replicated for testing on Earth (and we can't access directly for testing because of launch costs).
How thick can you be?

>>	Anonymous Mon Sep 26 15:50:25 2016 No.8372497 >>8372486 How can there be demand for something that doesn't exist? Every successful entrepreneur builds the product first, and the demand comes later Is there massive demand for going to space in the world? Yes, make it affordable and it'll happen.

Anonymous Mon Sep 26 15:59:24 2016 No.8372530

>>8372496
Yeah, how thick are all the experts when random internet guy knows so much better?

>Because of the high cost of spacecraft, a dramatic reduction in launch cost alone will not substantially lower spacecraft program costs. Although launching a pound of payload to LEO currently costs about $3,000, procuring that pound of payload typically costs much more. For example, representative U.S. spacecraft bussess of types first launched between 1963 and 1978 cost between $130,000 and $520,000 per pound dry, including amortized program overhead costs. Procurement of the mission payloads carried on those busses cost about 50 percent more—about $200,000 to $800,000 per pound. Reducing launch costs from $3,000 to $300 per pound of payload, a goal of the Advanced Launch System program, would reduce the total cost of procuring and launching a dry spacecraft (half bus, half mission payload) by less than 2 percent.

>A spacecraft bound for a high orbit or another planet requires an upper stage, which when fueled is typically more than twice as heavy as the spacecraft but costs less. Even so, a payload consisting of a Centaur upper stage (about $2,250 per pound) and a spacecraft weighing a third as much (half bus, half mission payload) might cost from $40,000 to $160,000 per pound.
Reducing launch costs to $300 per pound would reduce the total cost of procuring and launching such a payload by only 2 to 6 percent.

-- Affordable Spacecraft: Design and Launch Alternative, Background Paper, OTA, 1990

Right there, black on white: a 90% reduction in launch costs equates to 2-6% reduction of overall costs.

>>	Anonymous Mon Sep 26 16:02:59 2016 No.8372531 >>8372530 >how thick are all the experts when random internet guy knows so much better? "The experts" are often employed to crank out bullshit pseudologic to justify profiteering and big-budget careerism.

Anonymous Mon Sep 26 16:06:01 2016 No.8372541
File: 419 KB, 500x689, toiletpaper1.png [View same] [iqdb] [saucenao] [google]

>>8372497
>Every successful entrepreneur builds the product first, and the demand comes later
No, every successful entrepreneur builds the product for which there is demand. Like Edison and the light bulb. The unsuccessful ones build the product for which there's no demand. Like the head-mounted toilet paper dispenser.

>>	Anonymous Mon Sep 26 16:07:32 2016 No.8372544 File: 44 KB, 448x315, 47528305423407.jpg [View same] [iqdb] [saucenao] [google] >>8372531

>>	Anonymous Mon Sep 26 16:08:35 2016 No.8372549 >>8372497 >How can there be demand for something that doesn't exist? Finding that out is the hard/luck/risk part of innovation.

Anonymous Mon Sep 26 16:11:45 2016 No.8372559

>>8372531
>>8372530
Also: what kind of trash searches out "expert support" on the internet, cherry picks a bit out of context, and doesn't provide a link to the source?

https://www.princeton.edu/~ota/disk2/1990/9003/9003.PDF

The bit you quoted is part of the preamble of the document, framing the problem that spacecraft themselves are currently costly, therefore improving launch costs *entirely without changing anything about the spacecraft* would have a relatively small effect on overall costs.

The document as a whole strongly supports the idea that reduced launch costs can be used to reduce spacecraft costs.

Anonymous Mon Sep 26 16:19:28 2016 No.8372575

>>8372559
>The document as a whole strongly supports the idea that reduced launch costs can be used to reduce spacecraft costs.
No it doesn't. It discusses alternative concepts of payload design, not launcher design, precisely because it makes immediately clear where the cost reduction has to come from. Alternative launchers for example for the concept of allowing payloads to be five times as heavy for the benefit of reducing payload cost are taken for granted.

Anonymous Mon Sep 26 16:23:05 2016 No.8372583

>>8372559
>Also: what kind of trash searches out "expert support" on the internet, cherry picks a bit out of context, and doesn't provide a link to the source?
And what kind of complaint is that? I provided the source. I backed up my claim while your side of the argument didn't. Yet somehow I'm the bad guy? How silly and childish is that?

Anonymous Mon Sep 26 16:37:58 2016 No.8372612

>>8372427
>Plutonium-239 is itself a very nasty radioisotope you don't want to release

No it isn't, its a mildly radioactive alpha emitter. Theres nothing super special about it. When its blasted into the atmosphere by its own explosion it is not a risk to anyone.

>>	Anonymous Mon Sep 26 16:39:52 2016 No.8372618 >>8371390 cool, hope they can get it into use.

>>	Anonymous Mon Sep 26 16:51:29 2016 No.8372642 Funny how no one is discussing the rocket engine itself.

Anonymous Mon Sep 26 16:59:11 2016 No.8372661

>>8372583
>I backed up my claim while your side of the argument didn't.
So we're getting specific about what kind of trash you are. Posting other people's opinions, cherry-picked and distorted from papers you clearly haven't read in full, is "backing up your claim", while making good arguments and referencing common knowledge is "not backing up your claim".

>>8372575
>>The document as a whole strongly supports the idea that reduced launch costs can be used to reduce spacecraft costs.
>No it doesn't. It discusses alternative concepts of payload design, not launcher design, precisely because it makes immediately clear where the cost reduction has to come from.
>Alternative launchers for example for the concept of allowing payloads to be five times as heavy for the benefit of reducing payload cost are taken for granted.
"If payloads were allowed to be heavier for the same capability, some could cost substantially less"

Yeah, man. That is totally meant to shoot down the idea that lower launch costs can enable cheaper spacecraft to be built. How do you even twist it around in your head like that?

All four approaches it lists to lowering spacecraft costs revolve around the launch constraints: not using all the available mass (so there's margin for mass creep), using a much bigger launch vehicle (so special custom hardware can be avoided), building small, simple satellites (so they can launch on new small, low-cost launch vehicles or ride as secondary payloads), and building small, rugged satellites (so they can be launched on exotic systems).

You are such garbage. Such a total waste of time to talk to.

This is exactly what I mentioned earlier. Taking a purely adversarial approach to winning the argument, by your own standards, while lying and cheating like a motherfucker. Knowing that you're not arguing honestly, just trying to gratify your own ego by deluding yourself that you convinced some imaginary onlookers that you were right.

Anonymous Mon Sep 26 17:11:27 2016 No.8372685

>>8372612
>>Plutonium-239 is itself a very nasty radioisotope you don't want to release
>No it isn't, its a mildly radioactive alpha emitter.
It has a half-life of over 24 millennia and bioaccumulates. Alpha emitters are the worst radioisotopes to have in your body. Dust particles are particularly dangerous.

It's active enough to be a serious health risk, but long-lived enough to be an essentially permanent pollutant.

Routinely airbursting hundreds of Pu-239 bombs would make the whole world a carcinogenic mess.

Anonymous Mon Sep 26 17:31:19 2016 No.8372749
File: 429 KB, 1000x1000, WEB12067-2011p.jpg [View same] [iqdb] [saucenao] [google]

>>8371394
FUSION! WE NEED FUSION!

Seriously though a nuclear fusion engine providing a constant high thrust and ultra high isp, is the key to not only space travel, but power itself.

A clean burning fusion engine could pretty much take us anywhere in the galaxy.

But to get back on topic.
>30mpa

Jesus fucking Christmas is no understatement, And there's supposed to be like 20-30 of these on the first stage?
Musk is litterally making the N1 all over again.

This thing is going to break the record for largest non nuclear explosion on first test flight.

>>	Anonymous Mon Sep 26 17:50:48 2016 No.8372796 File: 3.31 MB, 3443x4483, IMG_1639.jpg [View same] [iqdb] [saucenao] [google] We clearly need to build Michael Pournelle was right all along

>>	Anonymous Mon Sep 26 17:58:31 2016 No.8372816 >>8372642 Well yeah, the engine is pretty unremarkable except for meme attributes (reusability, muh mars colonization), so we are discussing the underlying memes

>>	Anonymous Mon Sep 26 18:02:45 2016 No.8372835 >>8372315 Ah yes, the engine design that requires hand waving in certain places to function.

Anonymous Mon Sep 26 18:08:48 2016 No.8372848

>>8372816
You can add "it's SpaceX" in the meme list.

Had an engine with the exact same characteristics be tested by China, Roscosmos or ESA no-one would give a shit. (And actually, there many existing russian and european engines which are more capable).

This board is such bullshit

>>	Anonymous Mon Sep 26 18:23:05 2016 No.8372891 >>8372816 >the engine is pretty unremarkable except for meme attributes >>8372848 >(And actually, there many existing russian and european engines which are more capable). Mental illness crew present and accounted for.

>>	Anonymous Mon Sep 26 18:25:15 2016 No.8372897 >>8372816 >>8372848 ? have you read anything?

Anonymous Mon Sep 26 18:39:17 2016 No.8372943

>>8372483
30% was a one-off, harshly-negociated discount for a launch that a has a great chance of blowing up. Future customers will never directly get that. It is however, what spacex will be able to do medium-term.

If they don't blow up too often, that is, which is a pretty large if

>>	Anonymous Mon Sep 26 18:42:25 2016 No.8372952 >>8372943 Why would a reused stage blow up?

Anonymous Mon Sep 26 18:51:35 2016 No.8372970

>>8372891
>>8372897
And here, we have the typical ultra-sheltered american netizen who can't possibly comprehend that other people might be doing better than spacex. 3MN of thrust is nothing exceptional, neither is 382s of specific impulse. The rest are irrelevant internal specifics.

SpaceX follows the paradigm of one-size fits all to use the same engine for both the lower and the upper stage, so it ends up with an engine that indeed does the required trade-off, neither hugely powerful, neither hugely efficient.

It suit SpaceX's delusional ideas perfectly, but the engine itself has indeed nothing exceptional.

>>	Anonymous Mon Sep 26 18:56:32 2016 No.8372975 >>8372346 >it really doesn't matter what "engine" they use at this point, the problem of this shitpiece always been the fuel tanks Methane doesn't need helium to pressurise, which is what caused both Falcon 9 RUDs.

>>	Anonymous Mon Sep 26 19:01:40 2016 No.8372981 >>8372970 highest chamber pressure highest Isp of any non-LH2 engine highest thrust to weight A lower thrust just means you put more engines in the rocket

Anonymous Mon Sep 26 19:20:58 2016 No.8373012

>>8372943
That's nonsense. The 30% discount has been announced and practically advertised as the initial rate for flying on a reused booster.

Most of the incremental cost of launching is in manufacturing the first stage, and the ceiling on flight rate (which determines how many launches you can spread your fixed costs over) is in first-stage production.

If they can use these things six times, that'll cut the number of engines they need to produce by 75%. They can go from launching once a month (with a mature expendable vehicle), to once a week, without expanding their factory. The benefits for Falcon Heavy are even better.

If they can reuse them indefinitely, after building their fleet of first stages by doing full-priced launches, then they can cut the number of engines they need to produce by 90%.

That's why they're talking about eventually getting a satellite launch down around $12 million with Falcon 9.

>>	Anonymous Mon Sep 26 19:24:47 2016 No.8373019 >>8372541 Gee, so why don't we all just make the products that are in demand ! Capitalism and entrepreneurship is so easy now !

>>	Anonymous Mon Sep 26 19:47:07 2016 No.8373046 >>8371390 >"Oh yes Musk, let me pay you $20,000 for sucking your cock 10 seconds longer" ~average plebbit user 8 to 10 that it'll only worsen their ""reliability"" issues they should just go ariane 6 route and ditch the whole "reusability" meme

>>	Anonymous Mon Sep 26 19:59:27 2016 No.8373059 >>8373012 ...and this new Raptor engine is meant to power a fully-reusable, low-maintenance vehicle, like an airliner to orbit, with highly automated operation, launch costs approaching the fuel costs, pretty good fuel economy, and the cheapest fuel.

Anonymous Mon Sep 26 20:52:57 2016 No.8373140

>>8372395
You silly cunts don't realize that literally every big boy in the aerospace industry is "indirectly subsidized," do you?

Military-industrial complex is not a meme.

DoD and other Fed agencies award bidd to Lockheed for way more than is necessary. Lockheed sources from BAE Systems for way more than js necessary.

Replace Lockheed and BAE wjth any of the big guns. They are all subsidized by ridiculous contracts.

The new private players play the same game, but their costs are lower. The government is willing to hash out these "indirect subsidies" on the off chance it permanently reduces their future contracts.

Use your fucking heads.

>>	Anonymous Mon Sep 26 21:00:39 2016 No.8373150 File: 86 KB, 880x495, MW-CZ625_elonmu_20141119142911_ZH.jpg?uuid=892ce690-7022-11e4-958c-5bbf9d830bf9.jpg [View same] [iqdb] [saucenao] [google] >>8372749 >This thing is going to break the record for largest non nuclear explosion on first test flight.

>>	Anonymous Mon Sep 26 22:18:55 2016 No.8373221 >>8372362 >10-20% gives you the solar system Are you retarded?

>>	Anonymous Tue Sep 27 01:05:52 2016 No.8373422 >>8372362 You can't make bombs with 20% enriched uranium

Anonymous Tue Sep 27 01:20:07 2016 No.8373433

>>8372486
>payloads don't cost that much because of launch costs but because they have to work reliably for many years without any maintenance at all in a very harsh environment which can't be fully replicated for testing on Earth.
Yes, exactly, and these things are expensive because nobody is doing it on a mentionable scale. As more companies build satellites and spacecraft, these processes will become more and more like standard assembly line procedures and the costs of performing them will drop dramatically. Building satellites is only expensive because we do it so ridiculously infrequently.

Anonymous Tue Sep 27 01:27:22 2016 No.8373441

>>8373140
And worse, with companies like Lockheed the huge piles of cash the government hands them largely gets pissed away on an endless hierarchy of subcontractors, each taking a generously large slice of the pie. If these contracts went to SpaceX, all that cash that would've disappeared into the nether is instead immediately reinvested in R&D and infrastructure because they do as much as possible in-house. SpaceX doesn't have a choice in the matter – if they squander what they earn, they die, and they're fully conscious of that.

Old space has been riding cost+ the gravy train for so long that they couldn't make proper use of revenue if their lives depended on it.

Anonymous Tue Sep 27 01:56:43 2016 No.8373487

>>8372661
Wow, take a look at you, retard.

>Posting other people's opinions
Other people's research. And writing where you got it from. Yeah, that's a core part of the scientific method. What did you do? Hide your lack of substance behind a wall of personal insults. Weak.

>cherry-picked and distorted from papers you clearly haven't read in full
So you claim, but can't back up that claim, nor provide a quote from the paper yourself to support your view or from any other paper.

>making good arguments and referencing common knowledge
Is that what you think you did? Hilarious.

>"If payloads were allowed to be heavier for the same capability, some could cost substantially less"
Wow, just wow! You trying to prove that my statement that the paper investigates alternative concepts of payload design instead of launcher design is wrong and rather supports your claim about lowering launch costs as prerequisite to lower space operations costs by quoting a statement about how payloads could be made cheaper. Honestly, what are you even doing on /sci/? You don't lack just evidence to back up your claim. You lack basic reading skills to the point where the reader has to consider that you may be just a troll.

>All four approaches it lists to lowering spacecraft costs revolve around the launch constraints: not using all the available mass (so there's margin for mass creep), using a much bigger launch vehicle (so special custom hardware can be avoided), building small, simple satellites (so they can launch on new small, low-cost launch vehicles or ride as secondary payloads), and building small, rugged satellites (so they can be launched on exotic systems).
How about you back up your claims with quotes instead of just making things up?

Anonymous Tue Sep 27 02:28:22 2016 No.8373524
File: 850 KB, 1885x3044, C__Data_Users_DefApps_AppData_INTERNETEXPLORER_Temp_Saved Images_fFjFKXz.jpg [View same] [iqdb] [saucenao] [google]

Glad to see the test went well. Hope continued testing goes just as well.

Yeah, the stats are good, sure there might be better engines for in atmosphere, better ones for space, but no others are being built to be reusable. At the end of the day, if you can use the same engines for 3 flights, then that's a third less new engines that need to be built.

>comparing finances of organizations that have been going for 25+ years to 10 year old company
Everyone has gotten subsidies when they started. Its in their benefit to help out new companies that introduce competition to the market so that long term costs decrease.

Launch costs, when your launch vehicle fully fueled costs 70mil, and your satellite cost 150mil, every little bit helps. Generally speaking, the only thing that will bring down payload costs is manufacturing. Each satellite is custom (for the most part). They are designed with a very specific task that is probably not already in orbit. Shit ain't cheap yo.

>NPP will change spaceeeeee
No. It will never happen. No government will allow you to build a rocket that launches from earth that uses nuclear propulsion. Doesn't matter what particles are emitted, if there is a catastrophic failure it will result in multiple uncontrolled reactions that will release high energy radiation.

But anon, they use plutonium in the satellites to power them in space! Yeah, cuz its such a small amount that a failure on the pad wont result in the whole area being quarantined.

That said, using a fusion reactor to power an electrical engine is the best near-future feasible option. Yeah, we still haven't built one that can power itself yet, but by the time we can economically build ships in space, fusion should be attained by then. On stellar scaled distances, the little bit of acceleration increase by detonating fission reactions behind the ship are far outweighed by safety and failsafes.

Point is, we should all be happy that this is a step in the right direction.

>>	Anonymous Tue Sep 27 07:23:32 2016 No.8373916 File: 35 KB, 350x500, backinmyday-bet.jpg [View same] [iqdb] [saucenao] [google] >>8371429 >I'd wager there is no wagering at 4chan, Grandpa

>>	Anonymous Tue Sep 27 08:21:01 2016 No.8373957 I honestly wish that nuclear propulsion fags would kill themselves

>>	Anonymous Tue Sep 27 08:36:00 2016 No.8373973 File: 87 KB, 821x624, nukespace1b.jpg [View same] [iqdb] [saucenao] [google] SSS AAA FFF EEE TTT YYY

Anonymous Tue Sep 27 14:21:57 2016 No.8374496

>>8373524
RTG's actually have lots of radioactive plutonium
And no, nukes do not accidentally detonate

nuclear electric launches from earth are very possible & feasible, just need tons of power to weight, which is currently bad but won't always be bad.

>>	Anonymous Tue Sep 27 15:01:29 2016 No.8374685 File: 89 KB, 706x398, N1+1motors.png [View same] [iqdb] [saucenao] [google] Jesus christ that's a lot of motors.

>>	Anonymous Tue Sep 27 15:06:02 2016 No.8374716 >>8374685 https://youtu.be/0qo78R_yYFA

>>	Anonymous Tue Sep 27 15:16:16 2016 No.8374780 event thread here >>8374410 event thread here >>8374410 event thread here >>8374410 event thread here >>8374410 event thread here >>8374410

>>	Anonymous Tue Sep 27 18:02:33 2016 No.8375745 >>8373019 see >>8372549

Anonymous Tue Sep 27 18:11:34 2016 No.8375761

>>8373433
They will drop, yes, but not "dramatically". Learning curve effects are well understood. In aerospace increasing the production tenfold lowers unit costs by approximately 42%. That's good but markets don't just expand by a factor of ten over night. The most important commercial space launch market, the market for GEO comsats, has been pretty constant for several decades: about 25 satellites per year.

>>	Anonymous Tue Sep 27 18:14:13 2016 No.8375765 >>8372796 why does that shit have turrets lmao

>>	Anonymous Tue Sep 27 18:18:34 2016 No.8375772 >>8371390 >le fill a cylinder with chemicals and start burning on one end Literally boring. Waiting for /memedrive/

>>	Anonymous Tue Sep 27 18:32:08 2016 No.8375798 Tell me when they blow up another zuckerberg satellite. Best thing spacex has ever done.

>>	Anonymous Tue Sep 27 18:39:54 2016 No.8375815 >>8373140 >>8373441 good posts. Also don't forget that ULA gets $1 billion a year outside of launch contracts just for "assured capability". Talk about subsidies!

>>	Anonymous Tue Sep 27 18:42:17 2016 No.8375818 >>8375765 because it was built for an alien interplanetary war, and the author had a huge military boner

>>	Anonymous Tue Sep 27 18:44:00 2016 No.8375824 >tfw you'll never be smart enough to help with the development of groundbreaking aerospace technologies JUST

Anonymous Tue Sep 27 18:45:57 2016 No.8375831

>>8372981
it would also be the first engine using methane fuel to attain orbit (if they win the race with Blue Origin)

Honestly, there have been so many other fuel combinations used since the start of the space age, it amazes me that they are only now trying out methane.

>>	Anonymous Tue Sep 27 18:49:28 2016 No.8375840 File: 648 KB, 1080x1920, Screenshot_20160920-122039.png [View same] [iqdb] [saucenao] [google]

>>	Anonymous Tue Sep 27 19:04:19 2016 No.8375871 File: 429 KB, 1920x1080, Screenshot_20160927-200244.png [View same] [iqdb] [saucenao] [google] https://en.m.wikipedia.org/wiki/Project_Echo

>>	Anonymous Tue Sep 27 19:16:15 2016 No.8375893 >>8375871 >.m kill yourself

>>	Anonymous Tue Sep 27 19:51:34 2016 No.8375954 >>8375815 the CEO of the ULA said thats not a subsidy m8 on reddit He said thats just them paying for their launches with 2 different contracts

Anonymous Wed Sep 28 02:05:26 2016 No.8376803

>>8375831
>Honestly, there have been so many other fuel combinations used since the start of the space age, it amazes me that they are only now trying out methane.
Well, the only reason is that NASA endorsed the concept with the design reference mission. They hope to get more taxpayer money. Compared with RP-1 or LH2 methane brings you the worst of both worlds. It's only advantage is using propellant made on Mars.

>>	Anonymous Wed Sep 28 02:35:04 2016 No.8376859 File: 441 KB, 1024x656, spacex-cf-fuel tank.png [View same] [iqdb] [saucenao] [google] >>8372346 You Wot ????

>>	Anonymous Wed Sep 28 02:59:33 2016 No.8376893 >>8376803 ?? methane brings the best of every world It is the best chemical fuel to use by every single standpoint what are you saying

Anonymous Wed Sep 28 03:45:00 2016 No.8376958

>>8375824
Um, I hate to burst your SpaceX fairytale bubble anon but not everyone working here is a genius. In fact, while there are a few that I would classify as bonafide geniuses, the vast majority are just hard working competent engineers. Being a good engineer is a very reachable goal if you're willing to put the effort in and don't suffer from a diagnosed cognitive disability.

If you don't want to take the engineering route you could always go the technician route. I personally have hired techs with little to no aerospace experience but who seemed very reliable just so I wouldn't have to deal with the bad habits more experienced techs have picked up elsewhere.

Anonymous Wed Sep 28 13:32:07 2016 No.8377678

>>8376893
Its Isp is closer to RP-1 than LH2 - the worst of both worlds.
It's a cryogenic fuel like LH2 - the worst of both worlds.
The temperature range at which it's liquid is rather narrow, like LH2, complicating lubrication and cooling - the worst of both worlds.
As the densities of LOX and RP-1 are close enough together it's easy to operate both turbopumps with a single turbine, not so with LH2 or methane - the worst of both worlds.
With regard to tank weight the density of methane puts it somehwat between both worlds. Definitely higher tank weight and thus higher dry mass compared to RP-1 but not as bad as LH2.
You get the same engineering challenges as with LH2 in almost every aspect for such a little increase in Isp that it's really not worth it. The only real advantage is the possibility of using in-situ produced methane on Mars.

Anonymous Wed Sep 28 14:44:50 2016 No.8377803

>>8377678
It is methane fuel that has allowed SpaceX to produce their full flow staged combustion engine that has the highest thrust to weight ever made, and highest Isp of a hydrocarbon engine.

The Isp gains of LH2 are not worth the headaches of dealing with it, just in normal expendable launch vehicles. Could you reuse an LH2-LOx engine/tank 1000+ times with little refurbishment? Nope.

Since we're talking reusable, the cost of propellant is a relevant concern, methane is by far the cheapest.

Methane is not deeply cryogenic like LH2, its actually kept warmer than LOx, so there is no big engineering issue with it.

We will see all launch vehicles & companies going Methane soon because its just objectively superior in every regard.

Anonymous Wed Sep 28 15:08:58 2016 No.8377850

>>8377678
>Its Isp is closer to RP-1 than LH2 - the worst of both worlds.
Seems right in the middle to me-Merlin 1D-300, Raptor 380, SSME-450
>It's a cryogenic fuel like LH2 - the worst of both worlds.
Hardly the same level of cryogenics as LH2, with the melting point of methane 70K warmer than the boiling point of H2. It's almost the same as LOX anyway, so the two tanks don't need to be insulated from each other
>The temperature range at which it's liquid is rather narrow, like LH2, complicating lubrication and cooling - the worst of both worlds.
Fair enough, but FFSC engines use complete gasification anyway.
>As the densities of LOX and RP-1 are close enough together it's easy to operate both turbopumps with a single turbine, not so with LH2 or methane - the worst of both worlds.
Hmm? Density has nothing to do with why full flow stage combustion engines have separate oxidizer/fuel turbines.
>With regard to tank weight the density of methane puts it somehwat between both worlds. Definitely higher tank weight and thus higher dry mass compared to RP-1 but not as bad as LH2.
Fair enough, liquid methane is about 60% the density of RP1
>You get the same engineering challenges as with LH2 in almost every aspect for such a little increase in Isp that it's really not worth it. The only real advantage is the possibility of using in-situ produced methane on Mars.
There's the whole hydrogen embrittlement and extreme permeability that methane doesn't have to worry about

Anonymous Wed Sep 28 15:29:43 2016 No.8377899

>>8377803
>Could you reuse an LH2-LOx engine/tank 1000+ times with little refurbishment?
They have yet to show a single reuse with their current rocket and you're talking as if all of that other stuff already existed and worked as advertised.

>Since we're talking reusable, the cost of propellant is a relevant concern, methane is by far the cheapest.
Fuel is per se the cheapest part of a rocket, no matter if methane or RP-1 or LH2. You don't get cost reduction by chosing a cheaper fuel as the impact is negligible.

>Methane is not deeply cryogenic like LH2, its actually kept warmer than LOx, so there is no big engineering issue with it.
Yes there are. It's one thing to use a cryogenic oxidizer. It's something completely different if the fuel is cryogenic, too, because the fuel has additional functions. It has to be used as lubricant and as coolant. RP-1 is liquid over a very wide temperature range. Thus it can take up a lot of heat. Methane, like LH2, doesn't. Cryogenic fuels require special attention to moving parts. Because at these temperatures metals and composites are as brittle as glass. And one has to use special materials so that they don't stick together at these temperatures. As I said, with methane you get the same engineering challenges as with LH2 in almost every aspect.

>>	Anonymous Wed Sep 28 15:32:51 2016 No.8377906 NUCLEAR U C L E A R

Anonymous Wed Sep 28 16:03:39 2016 No.8377977

>>8377850
>Seems right in the middle to me-Merlin 1D-300, Raptor 380, SSME-450
Not everyone builds engines as shitty as SpaceX. RD-0124 achieves 359s. And Raptor has yet to prove it reaches the Isp they aim for.

>Hardly the same level of cryogenics as LH2, with the melting point of methane 70K warmer than the boiling point of H2. It's almost the same as LOX anyway, so the two tanks don't need to be insulated from each other
Insulation isn't a problem. Lubrication and cooling are. Materials are. Engineering is.

>Fair enough, but FFSC engines use complete gasification anyway.
The expensive part of a rocket is the development. Increasing the engineering challenges must be compensated for by performance or else the price per pound to orbit increases. LH2 justifies it. Methane doesn't.

>Hmm?
I was explaining why the combination of RP-1 and LOX makes for a simple engine design, which methane prohibits. Hence, it's the worst of both worlds for this additional aspect.

>There's the whole hydrogen embrittlement and extreme permeability that methane doesn't have to worry about
The permeability isn't really a problem as the time a rocket operates is short enough anyway. Hydrogen embrittlement takes exposure time. Rockets are fueled immediately before take-off. But materials do become brittle due to cryogenic temperatures. At these temperatures material loses tensile strength, which makes building rotating parts like turbines much more difficult. That's no comparison to a fuel that's liquid at room temperature.

Anonymous Wed Sep 28 16:55:33 2016 No.8378106

>>8372981
>highest chamber pressure
Irrelevant. If anything it makes the engine much more dangerous in case of a manufacturing defect.
>highest Isp of any non-LH2 engine
Very specific records always make me laugh, especially when announced non-ironically.
>highest thrust to weight
Completely irrelevant for a rocket since the engine is probably less than 1% of the rocket's weight while propellant makes up about 80% of the rocket's weight.
>A lower thrust just means you put more engines in the rocket
All the more potential failure points. The N1 also had a shitton of small engines, and it didn't end really well. The only advantage of such a configuration is that... its cheaper. And given SpaceX' less-than-stellar record on safety, mostly due to their habit of cutting corners, this really doesn't bode well for his big meme rocket.

>>	Anonymous Wed Sep 28 17:04:12 2016 No.8378119 >>8378106 >Very specific records always make me laugh, especially when announced non-ironically. >"This is the fastest wooden car with triangular plastic tires powered by a Stirling engine"

Anonymous Wed Sep 28 17:12:12 2016 No.8378129

>>8377899
If reuse doesn't work then we're never going to mars, and SpaceX will close down
If space travel doesn't get down to a small multiple of the fuel cost then we're never going to mars.

Since spacex HAS fired their Raptor engine already, I'm sure they've worked out whatever issues you think they might have.

They have done numerous ground test fires of landed stages btw.

>>8378106
>chamber pressure and t/w ratio is irrelevant
k

Anonymous Wed Sep 28 17:22:37 2016 No.8378151
File: 219 KB, 822x462, smug musk.jpg [View same] [iqdb] [saucenao] [google]

The year is 2075. You're driving down the road going past Tharsis Bulge, enjoying the fresh rover smell of the Olympus model you bought from Tesla Motors, one of the many thriving companies in the booming Martian economy. You turn on the radio to listen to the inauguration speech of the newly appointed president of EarthGov, Mohammed Zheng Wao de Silva. You hear a strange sounding woman trying to sell you the latest model of air purification masks, and you swiftly tune to a Martian channel, thankful that Emperor Musk banned advertising long ago. You can only make out bits and pieces of Mohammed de Silva's garbled Earther patois, so you turn on your Stallman brand real-time personal translator, reassuringly free of sponsored ad-delay translations introduced by the tech companies of Earth. You hear about the need to bring Mars back into line, to ramp up production of purification masks in the gulag factories of Luna. There had been stories from the freedom fighters of the failed Lunar Uprising about the need to wear purification masks in the majority of Earth's cities, but you believed they were exaggerations before hearing them from the president's own lips. You smile as you breathe in the clean air made possible by the scientists and engineers who escaped earth on the Martian colonisation ships launched by SpaceX.

You park your Olympus rover in the driveway of your beautiful Martian estate overlooking Valles Marineris. Your lithe and perpetually youthful wife runs out to greet you, and you're thankful that you managed to snag her on sale when the local Tesla Robotics showroom was celebrating the Golden Jubilee of Musk's coronation as Emperor of Mars. You kiss your wife, turn off her control switch, and head into your study.

You sit down and pour yourself a glass of single malt made in the distilleries dotting Albor Tholus. As you breathe in the peaty vapours and take your first sip, you think to yourself: "Thank God I believed in Elon Musk".

>>	Anonymous Wed Sep 28 17:24:30 2016 No.8378157 >>8378151 No drugs No alcohol No cigarettes

Anonymous Wed Sep 28 17:30:43 2016 No.8378173

>>8378129
>If reuse doesn't work then we're never going to mars
iirc neither NASA's design reference mission nor e.g. Zubrin's Mar sDirect plan call for reusability.

>If space travel doesn't get down to a small multiple of the fuel cost then we're never going to mars.
Outright silly assertion. The journey to the Moon wasn't a small multiple of the fuel cost either but it was doable.

>Since spacex HAS fired their Raptor engine already, I'm sure they've worked out whatever issues you think they might have.
One thing that makes space difficult is that you can't test for everything on Earth. The first flight of Ariane 5 ECA, for instance, was a failure because of insufficient cooling. The testing on the ground went ok. But the surrounding air carried away more heat. During actual operation in space this led to overheating of the engine due to fissures in the cooling tubes. I already talked about how methane makes things difficult for cooling, analogous to LH2.

Anonymous Wed Sep 28 17:38:20 2016 No.8378183

>>8378173
None of those things are mars colonization plans, they are just footprints & flags missions, much like Apollo was.
Then at at the end of it, you've spent 200 billion dollars for absolutely nothing to show for it.

>I already talked about how methane makes things difficult for cooling,
I don't see how cryogenic fuel makes it harder to cool the nozzles, if anything its better.
Something like that would come out in modelling or testing anyways

Anonymous Wed Sep 28 18:02:51 2016 No.8378213

>>8378183
>None of those things are mars colonization plans
Zubrin's book does cover colonization, too, including terraforming. Besides, your were talking about "going to mars". No word about colonization. And already that was a deviation from the discussion about how methane is the worst of both worlds when compared to RP-1 and LH2.

>I don't see how cryogenic fuel makes it harder to cool the nozzles, if anything its better.
Then pick up an engineering book instead of telling the world your cluelessness.

>Something like that would come out in modelling or testing anyways
Right, and rockets never ever explode, because everything is being simulated beforehand. So we have 100% knowledge, right?
Dude, don't be stupid. If simulation is so good, where was that simulation in those three Falcon 1 fuckups and two Falcon 9 fuckups? Why didn't they simulate that before to prevent these failures?

>>	Anonymous Wed Sep 28 19:27:31 2016 No.8378365 https://youtu.be/oM5fKcU5ClI

>>	Anonymous Wed Sep 28 19:51:02 2016 No.8378428 >>8378213 the SSME cools its nozzle with Liquid Hydrogen So go ahead and explain to me how you can't feed liquid methane through pipes to cool the nozzle. Obviously defective parts can't be simulated for

Anonymous Thu Sep 29 01:32:33 2016 No.8379076

>>8378428
>the SSME cools its nozzle with Liquid Hydrogen
>So go ahead and explain to me how you can't feed liquid methane through pipes to cool the nozzle.
Are you stupid? I never said you can't. I said it complicates the engineering and development which makes everything more expensive. If you're trying to make spaceflight cheaper by a factor of 10.000 within the next ten years but haven't even achieved a factor of 2 in the last ten years (i.e. Musk and SpaceX), you shouldn't aspire to replicate the Shuttle's technology.

>>	Anonymous Thu Sep 29 02:32:27 2016 No.8379168 >>8376958 What would those bad habits be?

>>	Anonymous Thu Sep 29 02:39:34 2016 No.8379178 >>8378151 Why did this feel like reading the cover of a new Expanse-novel?

Anonymous Thu Sep 29 02:53:29 2016 No.8379195

How the fuck is he going get 42 engines to ignite at the same moment? What happens when one of them explodes and takes out the surrounding engines causing a chain reaction? Even at 99 percent reliability: 1 - .99^42 = 34% of the time at least one engine will fail.

>>	Anonymous Thu Sep 29 02:59:20 2016 No.8379202 >>8379195 It will recreate the N1 rocket explosion.

Anonymous Thu Sep 29 02:59:43 2016 No.8379203

>>8379195
I can see it now, when they launch the crew into space, they need to launch the tankers several times too, which will never all happen. So the crew ends up floating in orbit for a week until they realize the tanker exploded and they need to go back.

>>	Anonymous Thu Sep 29 03:17:43 2016 No.8379221 >>8379203 as if they wont be able to spot the flash and subsequent mushroom cloud as Florida is finally pushed back under sea level...

>>	Carbon Thu Sep 29 03:32:57 2016 No.8379240 >>8371390 >inb4 it fireballs on maiden interplanetary flight calling it now

>>	Anonymous Thu Sep 29 04:48:54 2016 No.8379306 >>8371390 >I have no idea what these numbers mean or how they compare to other rockets >>8371394 This

>>	Anonymous Thu Sep 29 05:02:32 2016 No.8379319 >>8379306 Obviously the specific impulse is not going to be as good since it uses methane instead of hydrogen. That thrust number is great though. Also it has great sea-level performance 334s Isp as well.

>>	Anonymous Thu Sep 29 05:26:58 2016 No.8379340 Memedrive >> this shit

>>	Anonymous Thu Sep 29 08:45:11 2016 No.8379531 Yawn, the RD-170 is better and it was designed 40 years ago.

>>	Anonymous Thu Sep 29 08:46:50 2016 No.8379533 >>8379340 The difference is this shit works and doesn't break physics.

>>	Anonymous Thu Sep 29 11:46:29 2016 No.8379858 Why not just move the spacetime around the vehicle instead of moving the vehicle through spacetime

>>	Anonymous Thu Sep 29 11:50:22 2016 No.8379867 File: 19 KB, 403x392, efd.jpg [View same] [iqdb] [saucenao] [google] >>8379858 This post has been seized by the Central Intelligence Agency. No further comments shall be made.

Anonymous Thu Sep 29 11:52:56 2016 No.8379873

>>8379531
Glad I'm not the only one who gets it. Musketeers getting excited over this have probably never heard of another engine than the Merlin, which is itself pretty mediocre, so they get all amazed when spacex comes up with something slightly better. Absolute melts, the whole lot of them

>>	Goldberg Thu Sep 29 12:08:02 2016 No.8379921 >>8379531 How is RD-170 or 191 better?

Anonymous Thu Sep 29 13:08:15 2016 No.8379993

The SpaceX ITS rocket can lift the ISS as a single piece.

So if it comes to reality as advertised and can land more reliably than the Falcon 9s can. We are not only going to see regular travel to Mars. We are going to have space stations become cheaper and more common. As any one with the cash can build a station on Earth. Fold it up and put it into orbit as a single unit. Eliminating the years of launches and space walks that the ISS needed.

Anonymous Thu Sep 29 13:12:29 2016 No.8380002

>>8379993
Yep, this part of it is almost just as exciting....

If you stuff an ITS full of bigelow 2100s, you could launch 12 times the volume of the ISS for 2% of the cost

Space stations up the wazoo

Or, you could launch an entire iridium style constellation in ONE LAUNCH

Anonymous Thu Sep 29 13:18:28 2016 No.8380018

>>8378151
More like 2575 if you want clean air on mars.
Probably even longer.

>>8379993
Isnt ISS getting close to its expire date?
I read somehwere that NASA, ESA, the russians, and the chinks where all looking in to building there own huge station because nobody wants to chip in on building a international one anymore.

Anonymous Thu Sep 29 13:32:47 2016 No.8380047

>>8380018
Russia wants to take their parts and use it to start a new station.

>>8380002
think about this.

A standardized mass produced space station. designed specifically to fit on an ITS, get it self into orbit after separation, unfold, and be habitable with a few hours of a crew from a Dragon 2 going around in space suits to finish set up.

Anonymous Thu Sep 29 13:40:47 2016 No.8380063

>>8380047
>Russia wants to take their parts and use it to start a new station.

And ESA and NASA? are they holding out or something?

>think about this.
>A standardized mass produced space station. designed specifically to fit on an ITS, get it self into orbit after separation, unfold, and be habitable with a few hours of a crew from a Dragon 2 going around in space suits to finish set up.

If it were that cheap then every rich western country would buy one.

Anonymous Thu Sep 29 13:48:41 2016 No.8380080

>>8380047
>>8380063

I always thought that a High Justice-type system would be neat

You have a field of nuclear reactors, and a gigantic laser

Then you burn away at ablative material on a stupid cheap single stage rocket for 2-3 people

Cheap busses to stations, basically

Sort of like these https://youtu.be/LAdj6vpYppA

>>	Anonymous Thu Sep 29 14:23:38 2016 No.8380168 >>8380047 >Russia wants to take their parts and use it to start a new station. Why do i get the mental image of WH40K Orcs each time someone discusses soviet/russian engineering?

>>	Anonymous Thu Sep 29 14:50:40 2016 No.8380213 File: 76 KB, 400x352, Atlantis_Docked_to_Mir[1].jpg [View same] [iqdb] [saucenao] [google] >>8380168 Slavs are Orks.

>>	Anonymous Thu Sep 29 15:01:45 2016 No.8380239 >>8380080 looks like dumb meme shit

>>	Anonymous Thu Sep 29 15:23:04 2016 No.8380280 >sign up for the mission >spend years training >fuck yeah I'm gonna go to Mars >rocket blows up on the launch pad like 90% of SpaceX's rockets zoz

>>	Anonymous Thu Sep 29 15:25:22 2016 No.8380285 >>8380280 its ok you will survive with their launch escape.... oh wait it doesn't have one lol nvm ur dead

Anonymous Thu Sep 29 15:44:27 2016 No.8380318

>>8371417

is not that simple, the plater will withstand a lot of energy and presure constantly eroding it(just think that at the end of the trip you might have an excess of "practical medical isotopes" at your feet), then everytime a bomb explodes the use of the "clasical" neumatic system might be too masive or insuficient to compensate, and at the end there are practical problems.

One of the reasons behind the partial nuclear ban(the one that prohibited nuclear explosions in the atmosphere and hence in space) was because the nuclear tests blew of around 1/3 of the satellites around low Earth orbit, that means that an Orion drive can't start working on Earth or the atmosphere but rather in a high orbit(and considering a linear model for radiation posioning I'm not even worried about the fallout).

To do that you need a coordinated effort to put a giant spaceship in orbit full of nukes and when this happens then you have to take into account 2 things.

>If we could put the whole thing into such orbit then we don't need it in the first place to reach other places since we have already scaped Earth with a lot of mass.
>If we could divide the thing into several modules and join them together then we can already do that with ourr current designs, is just that no one wants to, and we don't have a need for that.

I'm not saying that is not stupid, nor that it cannot be achieved, technical problems can be solved and coordination/political problems can be overcomed with time, patience and will, its just that is like trying to solve all problems of space travel with a hammer.

The real solution here is the creation of a space logistic infraestructure that goes from Earth to the asteroid belt, because what we are really lacking is the ability to have something with enough "gas" to go back from another planet, and as far as I know, every single time a travel revolution happened it had to start with either a special engine/vehicule or an efficient logistic network.

>>	Anonymous Thu Sep 29 16:00:16 2016 No.8380355 >>8371390 Didn't we invent the bomb a while ago already?

>>	Anonymous Thu Sep 29 16:16:32 2016 No.8380390 >>8373221 No I am not :) >>8373422 I am not talking about bombs.

>>	Anonymous Thu Sep 29 16:21:01 2016 No.8380395 >>8379858 We dont want to break causality son!

>>	Anonymous Thu Sep 29 16:53:38 2016 No.8380450 >>8380285 Dragon2 does. Mars ships have rockets and fuel.

Anonymous Thu Sep 29 17:31:30 2016 No.8380502

>>8379168
It's mostly cultural/personality type stuff. Most aerospace/defense corps tend to be pretty hierarchical with wide barriers between the technicians/lower engineers and group/dept managers. You end up losing a ton of efficiency when middle managers are trying to carve out their little fiefdoms which we try to minimize here.

Some of the techs who've been in the industry a while, particularly in union shops, can be pretty hostile to input from engineers. Some of this might be warranted but more often it's just stupid turf shit. You also have some engineers who think that just because they recently graduated college they know better than a machinist with 25+ years experience, so this kind of bs flows both ways.

SpaceX tends to foster a much closer working relationship between techs and the engineering staff than most places.

You also tend to have a large number of veterans working as techs in any aero/defense corp and that brings with it a bunch of military spillover. I'm a vet and still serve in the ANG but I don't give a shit what someone's rank was in the Army 10 years ago. I like working with people who will call me out if I do something stupid, even if they work under me.

So it's mostly culture/fit but you also get technical procedures that can differ greatly between companies that form habits which are difficult to break, I can't talk much about those specifics though.

Sorry I'm typing from my phone but I'll try and answer if you have any follow up questions.

>>	Anonymous Thu Sep 29 23:42:37 2016 No.8381194 >>8380502 Nice to have you back SpaceXanon.

>>	Anonymous Fri Sep 30 06:27:05 2016 No.8381657 >>8380502 how far are you with the dragon2? how is working with nasa? is nasa mad about the MCT? what will fly on the falcon heavy? what are the coolest people at work? any cool stories?

>>	Anonymous Fri Sep 30 12:09:44 2016 No.8382203 >>8373422 >>8380390 You talking about the Zubrins nuclear salt water rocket? http://www.nextbigfuture.com/2016/09/robert-zubrins-nuclear-salt-water.html >400000psi chamber pressure

Anonymous Fri Sep 30 17:41:05 2016 No.8382763

>>8381657
>how far are you with the dragon2
From what I hear internally Dragon V2 is progressing relatively on schedule, better than some other projects at least.

>>8381657
>how is working with nasa?
Not much different than working with any other gov org or research partner, which means things can get tedious but otherwise we're all grown ups with a job to do. NASA's technical staff is top notch and in my experience has always been helpful.

>>8381657
>is nasa mad about the MCT?
The whole of NASA, no way. Most people at NASA are supportive of any efforts to get shit into space, whether that is through SpaceX's effort or someone else's. Bolden and some senior administrators probably aren't too happy about anyone doing deep space missions without having NASA in the lead. Of course, Bolden is a dumbass and also completely ineffectual so who gives a shit.

This whole NASA vs SpaceX vs BO vs ULA thing is just internet posturing from fanboys who neither currently nor will ever work in space launch. For the most part the people who work at these places just want to quietly do their work, get paid, and are generally pretty excited about anything advancing space exploration, even if it's a "competitor". No one at SpaceX works 70 hours and then thinks "this is all worth it to see the look on Tory Bruno's face".

>>8381657
>what will fly on the falcon heavy?
Heavy things that need to go into space.

Anonymous Fri Sep 30 17:50:48 2016 No.8382790

>>8381657
>what are the coolest people at work?
We're around 5k employees now so there are quite a few cool people. Propulsion has a really talented group led by Tom Mueller who's a legit genius when it come to engines. Musk has been pretty based the times I've interacted with him, but then I like his personality so I'm biased. There are some incredible machinists and welders who will make anything you ask of them. There's a couple of guys in the kitchen that are always funny to be around and they make great ribs and bbq. There are some CS/physics people who do computational/simulation stuff and that whole dept has some serious brain power.

>>8381657
>any cool stories?
Nothing that I would describe as both cool and willing to share unfortunately. In general it's a pretty fun environment to work in, although high pressure. I don't really get the sentiment some have of it being a meat grinder, the people here generally are fairly competent and nice to work with. It also tends to be a lot of fun and if you're here working crazy hours you end up making some good friends.

Anonymous Fri Sep 30 17:57:52 2016 No.8382805

>>8372975
they're still going to be using brand new carbon fuel tanks
and this is a flight that'll take at least 3 months, that's a lot of time for something to go wrong. And if one of those tanks loses pressure, at best they'll hit mars' atmosphere and burn to death, at worst they'll fly off in to interplanetary space and slowly starve to death

>>	Anonymous Fri Sep 30 18:01:25 2016 No.8382814 >>8382203 Yes that's it!

>>	Anonymous Fri Sep 30 18:13:34 2016 No.8382840 >>8382805 We send three or four vehicles so there is hope of rescue even if something goes wrong.

>>	Anonymous Fri Sep 30 20:33:48 2016 No.8383119 >>8382805 They'll have years of experience with these tanks, on the ground and in space, before they send any people to Mars on ICT. If it's still at all plausible that they'll crack during the coast phase, they won't go.

>>	Anonymous Fri Sep 30 21:03:11 2016 No.8383171 >>8372467 You play too much ksp.

>>	Anonymous Fri Sep 30 21:16:38 2016 No.8383197 >>8379921 It doesn't use meme fuel.

Anonymous Fri Sep 30 21:29:35 2016 No.8383226

>>8383197
>herp derp
The specific impulse (337s vacuum) is far inferior to what they're aiming for with Raptor (380s vacuum). The thrust-to-weight even moreso.

Raptor's about the same size as Merlin, with triple the thrust, and Merlin has about double the thrust-to-weight ratio as RD-170.

>>	Anonymous Fri Sep 30 21:34:06 2016 No.8383233 >>8383226 RD-170 was an 11-ton engine that provides about 8MN thrust in a vacuum. Merlin 1D's a half-ton engine that provides about 1MN thrust in a vacuum. Raptor should be well under a ton and provide over 3MN thrust.

Anonymous Sat Oct 1 04:48:06 2016 No.8383719
File: 69 KB, 432x350, 3VehiclesToMars.jpg [View same] [iqdb] [saucenao] [google]

>>8382840
If you send more vehicle, it would be more rational and economical to create an infrastructure first,
But hey, I know, I know, Mars-proponent believe colonization is so easy it will already pay-off in a few years..

>>8383119
Having years of experience mean nothing to Murphy's law. that's why the NASA was extremely prudent with a very modular design and several rescue plan.
Easy-Mars proponent like Elon Musk simply care less about loosing "a ship" in their grand plan.
And who wouldn't if they believed than 9 ship out of 1 will save humanity...etc...etc ?

>>	Anonymous Sat Oct 1 05:07:28 2016 No.8383730 >>8380280 no need of training as Elon said in the Q&A, probably few hours during 2-3 days

>>	Anonymous Sat Oct 1 13:01:46 2016 No.8384240 >>8383233 These use different engine cycles and gas generator is superior to staged combustion in t/w ratio of the engine because it is simple in design but much less efficient compared with staged combustion engine.

>>	Anonymous Sat Oct 1 14:26:38 2016 No.8384383 >>8383719 Even sending two is a lot safer then sending one.I wouldnt get on that ship if we are departing alone. The bigger the fleet the safer people are.

>>	Anonymous Sat Oct 1 14:28:46 2016 No.8384385 >>8380285 >>8380450 Mars ship will be able to escape with their engines. On Mars though you either launch or you dont.

>>	Anonymous Sat Oct 1 18:12:56 2016 No.8384928 File: 56 KB, 470x483, 1455838604755.jpg [View same] [iqdb] [saucenao] [google] >>8372749 >And there's supposed to be like 20-30 of these on the first stage? yfw 42 engines

Anonymous Sat Oct 1 19:06:38 2016 No.8385012

>>8384240
Try to limit the depth of your bullshit.

>gas generator is superior to staged combustion in t/w ratio of the engine
Raptor, a staged-combustion engine, is going to have a much higher thrust-to-weight ratio than Merlin, a gas-generator.

>>8383719
Where do these idiots keep coming from? Of course they're going to build infrastructure before they start sending 100 people per ship.

>the NASA was extremely prudent with a very modular design and several rescue plan.
NASA HAS NO PLAN. NASA isn't going to Mars. Get that through your head. They have some vague wishes, and wave their hand at the stuff they're spending money on, implying that it's going to help somehow, but they have no fucking plan for going to Mars. SLS has nothing to do with Mars. Orion has nothing to do with Mars. ISS has nothing to do with Mars.

SpaceX has a preliminary plan. They will almost certainly not follow it exactly, because it involves changing the world along the way, and other people are also changing the world at the same time. They haven't revealed every detail, nor worked out every detail, and it is completely moronic to assume that the complete mission will be as simple as the sketch they've given.

You want backup options? SpaceX has the means to provide them. Dragon can carry 7 people and land on Mars. It weighs under 10 tons. ITS can carry 450 tons to Mars. The early manned missions (which will only happen after the first unmanned missions, and after several Dragon landings) will likely take enough Dragons as lifeboats for everybody.

>>	Anonymous Sat Oct 1 19:37:51 2016 No.8385053 >>8385012 In general gas generator engines are much simpler and are lighter compared with staged combustion engines just look at RD-0110 vs RD-0124 . Raptor has insane characteristics and it allows for such T/W.

>>	Anonymous Sat Oct 1 19:46:50 2016 No.8385061 >>8385053 The point was comparing Raptor and RD-170, not RD-170 and Merlin.

>>	Anonymous Sun Oct 2 08:16:24 2016 No.8385931 >>8382790 so where do you see the biggest hurdles technology wise? composites? orbital tanking? booster landing 1000 times?

>>	Anonymous Sun Oct 2 13:28:47 2016 No.8386463 >>8375798 Kek

Anonymous Sun Oct 2 14:31:34 2016 No.8386584

Man, Elon surely does seem to know what is coming. No wonder the engine name and such ambitious plans.
He is bound to succeed.

For those who will remain, do not accept the three branches of the human governments which are to come, for this is the mark of the beast. Do not give into the desire to do evil. The peace which will be established after all these conflicts will only be temporary.

Also, many will try to mislead you - both, those who claim to be religious, those who claim to be skeptical rationalists, and those who run conspiracy shows. They will try to tempt you into buying their lies. For the only God is the Word. The Word which was spoken was accepted by many and fulfilled. It was also rejected by some, which is leading to the establishment of the New Babylon, which, just like the old one, is that against the ideals of the lamb.

>>	Anonymous Sun Oct 2 14:45:03 2016 No.8386614 >>8386584 That thing's spelled "rapture".

>>	Anonymous Sun Oct 2 14:50:24 2016 No.8386626 >>8386584 lol

Anonymous Sun Oct 2 14:59:11 2016 No.8386645

>>8371887
>The main reason for high orbital launch costs is the lack of efficient reusability.

Uhm, no... the MAIN cost is using fucktons of fuel because even our BEST engines cap out at less than 400seconds.

The only way we are actually going to be able to ge tinto space with more than communications sattelites or small scale science probes, is with higher ISP engines.

Anonymous Sun Oct 2 15:27:49 2016 No.8386722

>>8385012
Honestly, I think it would be better to set up a lunar mining mission (for ore, processing, parts fabrication, and fuel production), and a luna space station (Rotating stanford torus) for long term mining missions (G reacclimation)

Sure, about the only fuel you're going to be getting in significant quantities on the lunar surface is Aluminum Oxide boosters, but that can be used to boost parts up into luna orbit, hell maybe even make a gauss gun launcher on luna....

Once we have the Earth/Luna infrastructure completed, missions to mars would be cheaper AND safer.

But, seriously.... Fusion powerplants are needed for cost effective boosting of large payloads (colonies)

>>	Anonymous Sun Oct 2 15:42:28 2016 No.8386752 >>8386645 fuel costs are like 200.000 out of 60.000.000 total. Kill yourself dont talk about shit you clearly know absolutely nothing about

Anonymous Sun Oct 2 15:56:14 2016 No.8386784

>>8386722
(continued)
>But, seriously.... Fusion powerplants are needed for cost effective boosting of large payloads (colonies)
*from terra

Did you guys know that there was a US military project (air force, iirc) to make a nuclear (U-Fission) thermal turbine?

Russia did one too, I think the US made like 3 different models, open cycle, closed cycle, and something else I can't really recall.

I think the reactor+shielding was too heavy to get it off the ground under a useful payload, so it got scrapped.

But technically, they DID work.

Anyways, I think that heavy isotope fission is far too massive a powerplant to ever be used *efficiently* (looking at you, Orion Drive) and *safely* (Looking at you, open cycle nuclear salt water rocket)

Personally, I feel that fusion powerplants and thrust engines are the key to opening up space exploration/colonization, but I feel there may be "Certain" ""Economic"" """Factors""" preventing fusion reactions from ever becoming anything more than a scientific curiosity.

(smelling a lot of feel coming off of this post...)

So, we got air breathing thrust turbines that are good for static thrust and low mach.

We got ramjets that are good for mid mach speeds.

And we got scramjets that are good for hypersanic fastness.

And, they are all air breathing reactions, which decrease your propellant fraction.

I think the SABRE concept was somthing along these lines, but they just used a cryo-cooled-super-turbo-air compressor/rocket, instead of shaping the initial >mach shockwave of the inlet through the combustion chamber (like Ram and Scramjet), and just went with "Turbocompress all the things!"

https://en.wikipedia.org/wiki/SABRE_%28rocket_engine%29

So, I guess you could say it's a highly modified sr-71, of sorts.

although, I will admit... the modifications are extensive.

I thought the idea of cryocooling the supersonic inlet air flow prior to compression was particularly clever.

>>	Anonymous Sun Oct 2 15:57:25 2016 No.8386786 >>8386752 >fuel costs are like 200.000 out of 60.000.000 total. And the cost of the giant fucking rocket to HOLD all of that fuel?

>>	Anonymous Sun Oct 2 15:59:30 2016 No.8386797 >>8386786 negligible if its reusable IN YOUR FACE

>>	Anonymous Sun Oct 2 16:03:39 2016 No.8386812 >>8386784 Unless we have a good place to test nuclear rockets we won't be able to make any progress. Mars research facilities will be very useful.

Anonymous Sun Oct 2 16:04:01 2016 No.8386814

>>8386786
>And the cost of the giant fucking rocket to HOLD all of that fuel?
(correction)

Sorry, I guess that was pronounced.... Giant fuel tanks, aerodynamic fairings, structural supports for all of that empty space, increased liftoff mass nessesitating increased propellant fraction, multi stage, asparagus style, discentigrating totem pole......

All for the fuel.

>>	Anonymous Sun Oct 2 16:05:43 2016 No.8386821 >>8386814 Scaling rockets isn't hard. Falcon was scaled two times already.

Anonymous Sun Oct 2 16:07:27 2016 No.8386824

>>8386797
>negligible if its reusable IN YOUR FACE

I chuckled.

Still, if you needed less fuel, you would also need less rocket to hold all of that fuel to get your payloads into orbit... sooooo.....

Your propellant fraction takes up a good part of your rocket, making more of your rocket into giant fuel tanks, that require structural bracing, insulation, etc...

Lower ISP = Better.

If it is at least of equal thrust to weight, that is...

>>	Anonymous Sun Oct 2 16:08:12 2016 No.8386827 >>8386814 >LEEE HUUUUURRR LE DUURRR IF ROAACKEETS DIDDNTT HAVE TO CARRY THEEIRR OWN FUEL THEIIY WOULD BE MUUCH BETTTEERRRR thats how you sound right now. remember 4chan is not for underage children

Anonymous Sun Oct 2 16:09:47 2016 No.8386834

>>8386821
>Scaling rockets isn't hard. Falcon was scaled two times already.

I'm not saying that it's difficult to do.

I'm saying that making the rocket BIGGER increases its cost.

Because strength increases by the area, and mass increases by the volume.

Anyways, I wasn't really talking about that at all.... but how High isp fusion engines are probably needed to do anything in space beyond probes and the occasional manned mission.

>>	Anonymous Sun Oct 2 16:11:21 2016 No.8386840 >>8386834 So long as you can refuel in orbit you have the solar system.

Anonymous Sun Oct 2 16:12:29 2016 No.8386843
File: 19 KB, 500x500, 500px-Tsiolkovsky_rocket_equation.svg.png [View same] [iqdb] [saucenao] [google]

>>8386827
>thats how you sound right now.

Nice argument, are you feeling well?

>IF ROAACKEETS DIDDNTT HAVE TO CARRY THEEIRR OWN FUEL THEIIY WOULD BE MUUCH BETTTEERRRR

That there's a strawman.

and I hope you feel bad about posting it.

>>	Anonymous Sun Oct 2 16:14:02 2016 No.8386847 >>8386843 ok you piece of shit, post your totally possible alternative to what they are doing now that doesnt imply le ebin technology that is always 50 years away

Anonymous Sun Oct 2 16:18:37 2016 No.8386862

>>8386840
>So long as you can refuel in orbit you have the solar system.

But at what cost?

Using chemical energy for propelling a spaceship interplanetary distances seems to me to be wasteful.

Consider the following:

A single launch for the mission, a second launch for the propellant, and a third launch for some type of nuclear engine.

LOX/CH4 when pumped by a nuclear reaction would be far more efficient in terms of propellant usage, and thus a much wider mission profile, and or orbital correction, mission abort manuvers, etc...

Also, SSTO's can be incredibly useful on any planet that doesn't already have a space industry.

Anonymous Sun Oct 2 16:20:55 2016 No.8386871

>>8386847
>ok you piece of shit, post your totally possible alternative to what they are doing now that doesnt imply le ebin technology that is always 50 years away

You seem kind of upset.... are you an anti-fusion shill? (if such a thing even exists)

Actually, Fusion power has existed for decades now.

Couldn't possibly think of a reason why were aren't using that instead of all of the petrolium fuels on the planet though.... not a single reason at all.

Anonymous Sun Oct 2 16:25:14 2016 No.8386882

>>8386871
>Fusion power has existed for decades now.
oh yes, clean cheap energy exists but the evil corporate powers dont wont you to have it!!

youre clearly an undeducated virgin tinfoil hat wearer, i hope you get to touch a girl at some point in your pathetic life so its not entirely a waste

please reply
it means im winning

Anonymous Sun Oct 2 16:26:10 2016 No.8386885
File: 2.76 MB, 4573x2942, 0_908fe_a3d8f6eb_orig.jpg [View same] [iqdb] [saucenao] [google]

>>8386871
Fusion will never be a cost-effective power source
>$200 billion and 40 years to build ITER, a single reactor with less output than a fission reactor, that might just not even work
lmao

Anonymous Sun Oct 2 16:26:36 2016 No.8386887

>>8386862
To develop nuclear rockets we must do it in some other planet or moon anon. For now we put a research center and some people on Mars with chemical rockets and as Musk claimed: this would be a good reason to develop advanced propulsion.
Everyone will try to get to other planets if we can actually colonize Mars. Of course you have to do nuclear, polluting research on Mars which will be economically useful to the colony.

Anonymous Sun Oct 2 16:29:16 2016 No.8386896

>>8386862
Nuclear propulsion will never happen until more government research happens (since private research on the topic is not legal)

Government research will never happen until the political scene changes, and greenpeace ilk and other "environmentalists" get out of policy influencing

There is also no indication that nuclear propulsion will ever be cost-effective.

>>	Anonymous Sun Oct 2 16:32:33 2016 No.8386905 >>8386885 wow that is one complex way to waste money, i think setting the 100$ bills on fire is much simpler and easier

>>	Anonymous Sun Oct 2 16:33:49 2016 No.8386907 File: 140 KB, 704x570, LF-ScanningAnalysis.jpg [View same] [iqdb] [saucenao] [google] >>8386882 >>8386885 >please reply >it means im winning I got some bad news for ya.

>>	Anonymous Sun Oct 2 16:36:31 2016 No.8386912 File: 126 KB, 1062x786, enterprise.jpg [View same] [iqdb] [saucenao] [google] >>8386896 >There is also no indication that nuclear propulsion will ever be cost-effective. Actually, that isn't accurate at all.

>>	Anonymous Sun Oct 2 16:37:41 2016 No.8386916 >>8386905 >wow that is one complex way to waste money, i think setting the 100$ bills on fire is much simpler and easier I'm wondering why they didn't make the test reactor a bit smaller.... to save money.

>>	Anonymous Sun Oct 2 16:38:28 2016 No.8386917 >>8386907 shure little kiddy boy, shure >>8386912 YOURE COMPARING HEATING WATER WITH USING NUCLEAR BOMBS TO PUT THINS IN ORBIT WIHTOUT BREAKING THEM

>>	Anonymous Sun Oct 2 16:40:17 2016 No.8386920 >>8386912 Who makes money by using aircraft carriers? Those things cost $1 billion a year a pop How is that cost effective?

Anonymous Sun Oct 2 16:46:14 2016 No.8386935

>>8386917
>shure little kiddy boy, shure

Keep crying.

>YOURE COMPARING HEATING WATER WITH USING NUCLEAR BOMBS TO PUT THINS IN ORBIT WIHTOUT BREAKING THEM

Hey, YOU are the one that said "Propulsion"

>>8386920
>Those things cost $1 billion a year a pop
>How is that cost effective?

Do you know a cheaper way to move multiple air wings to almost anywhere on the planet, and their ordinance, maintinance crew and parts, tools, radar, missiles, etc, etc, etc... and keep them ready to launch all the time?

Because so far, I don't believe there IS anouther way to do that, is there?

Anonymous Sun Oct 2 16:47:04 2016 No.8386937
File: 1.39 MB, 3000x1926, Soyuz_rocket_engines.jpg [View same] [iqdb] [saucenao] [google]

>>8378106
Why do people always bring up the N1?

You do realize that the R7 has thirty two (32) combustion chambers and 10 turbopumps and has flown more than 1000 successful flights?

Falcon heavy will have 27 engines and 52 turbopumps. They will have plenty of time to figure out large numbers of engines before the mars rocket flies.

>>	Anonymous Sun Oct 2 16:48:15 2016 No.8386942 >>8386935 You're just moving the goal posts now How will nuclear propulsion ever be more cost effective than chemical? (I'm talking about space travel, not ships)

Anonymous Sun Oct 2 16:54:21 2016 No.8386964

>>8386942
>How will nuclear propulsion ever be more cost effective than chemical?

IT already IS, yo.....

We just don't use it.

Unless you are talking about solar fusion plasma photon powered ion engines on sattelites.

That's KINDA fusion powered... but it AIN'T chemical powered, that's for damned sure.

And what about solar sails?

That's effecient as fuck... the Orion drive, the nuclear lightbulb, the nuclear salt water rocket, etc...

These are all technologies that will work, with off the shelf parts.

And THEY are more efficient than chemical powered rockets for space flight.

Nuclear is ALWAYS going to be more powerful than chemical, because the energy difference between vanalce shell charge differentials PALES in comparison to the strong force/weak force of nuclear interactions.

I think the power ratio is something like 2 million to 1.

>>	Anonymous Sun Oct 2 16:55:27 2016 No.8386969 >>8386942 >How will nuclear propulsion ever be more cost effective than chemical? As a specific example, a Radio Thermal Genorator hooked up to a hall effect thruster. MUCH better isp.

Anonymous Sun Oct 2 16:56:47 2016 No.8386977
File: 6 KB, 473x311, 1463809729483.png [View same] [iqdb] [saucenao] [google]

>>8386964
>>8386969
>Radio Thermal Genorator hooked up to a hall effect thruster
That's not fusion, in fact it's not even fission.

You have a genuine mental illness m8.
Get help.

>>	Anonymous Sun Oct 2 17:00:38 2016 No.8386988 >>8383171 i think you mean "just the right amount"

>>	Anonymous Sun Oct 2 17:01:08 2016 No.8386991 >>8386935 >Keep crying. lel, more like epically winning over you , little loser ignorance boy

>>	Anonymous Sun Oct 2 17:01:32 2016 No.8386993 >>8386824 >If it is at least of equal thrust to weight, that is... Aye, that's the rub.

Anonymous Sun Oct 2 17:03:33 2016 No.8386998

>>8386977
>That's not fusion, in fact it's not even fission.

Technically, it IS fission, as even nuclear decay heating is caused by energetic fission events in plutonium, uranium, or amerecium.

I think i've given enough examples of fusion in this thread, to be honest, neutron track counting and all that.

>You have a genuine mental illness m8.
Get help.

So, you ARE an anti Fusion shill, aren't you?

Who do you work for? Rock-Oil-Fella?

Anonymous Sun Oct 2 17:11:54 2016 No.8387019
File: 111 KB, 1600x842, 1418283151837.jpg [View same] [iqdb] [saucenao] [google]

>>8385012
While I actually agree that NASA don't actually expect (or care) for the mission, they are actually developing what you'd actually need for space exploration, they are producing lot of data basically for free.

Aren't you the one calling for messiah here ?
Relying on miracle from what have yet to prove a efficient launcher design isn't an infrastructure. That's what make the SpaceX fanboy so unbearable : always ignoring the little details, glorifying the average and believing their heroes are better than everybody else.

But let's make the points you will flatly ignore : SpaceX have yet to actually reuse their rockets even if I applaud the development and support the goal. Elon Musk is just a business man selling dream and taking his fame from others' work.
The ITS will indeed probably fly, even a brick would fly if you throw enough money at it. Space Shuttle anybody ?

The ITS simply won't accomplish anywhere close to what it's supposed to do. I'll be amazed if they can reuse a full Falcon 9 without loosing money (yes I don't doubt the feasibility), but I'll be ecstatic if they even get the first stage ITS in orbit.
Whatever SpaceX achieve we will applaud anyway, the support for rocket science is so bad they'll stay appreciated just for being showy.

Wait I forgot, when you say stuff like that you are told "you can't predict the future", it have to be a spaceX fanboy who do so.

>>	Anonymous Sun Oct 2 17:14:23 2016 No.8387026 >>8386998 Fusion doesn't need to be "anti shilled" There isn't a single energy-positive fusion reactor in the entire world.

>>	Anonymous Sun Oct 2 17:30:40 2016 No.8387077 >>8386645 fuel is like 1-2% of the total cost, dude

Anonymous Sun Oct 2 17:31:19 2016 No.8387080

>>8387019
Elon is not a businessman. He wants to go to Mars. Always has. Everything he does is for Mars.
As a Musk fan of I don't ignore details. I know all the details and conclude it's feasible.

Reuse gets better over time since you know what reentry looks like and what launch actual does to a vehicle if you get the ship back.

>>	Anonymous Sun Oct 2 17:34:53 2016 No.8387085 >>8387080 So far the only groups to have reused spacecraft are NASA and Blue Origin Spacex has a lot of shit to prove (reliability, reuse, actual innovation, ability to raise funding for the project) before their mars project can be called "feasible"

Anonymous Sun Oct 2 17:41:31 2016 No.8387103

>>8387085
Elon has ten billion dollars wealth.
Reuse is already demonstrated by landing since you fire the engines to land. If the rocket was ducked up it could not land.
They have innovated sea platform landing, propulsive landing, pica-x heat shield,grid fins on rockets and countless other things. Some they improved some (like 3d printing engines, fairing reuse) invented.
While everyone is going smaller he is going bigger. If it's possible they can do it.

Anonymous Sun Oct 2 17:42:03 2016 No.8387104
File: 1.31 MB, 3543x2408, sail.jpg [View same] [iqdb] [saucenao] [google]

>>8387026
>Fusion doesn't need to be "anti shilled"

>There isn't a single energy-positive fusion reactor in the entire world.

Did you miss the neutron track counts from up above?
>>8386907

...

>>8387077
>fuel is like 1-2% of the total cost, dude

I said:

"the MAIN cost is using fucktons of fuel"

Your rockets have to be HUGE to accomodate all of that fuel.

If they used less fuel, they could be smaller, cheaper, using less materials.

Tell me, what is the propellant ratio for pic related?

Anonymous Sun Oct 2 17:44:54 2016 No.8387116

>>8387085
>actual innovation
landing a booster thats used in an orbital mission and then test firing it for the actual duration of a new mission is pretty revolutionary, all thats left to be seen is if the rocket can withstand max q again and you have proven actual reusability which will be an absolutely total game changer

>>8387103
its not only demostrated by landing, its demonstrated by the fact that they reignited the rocket for the duration of a whole mission after teh test, all thats left is the actual mission

Anonymous Sun Oct 2 17:47:03 2016 No.8387121

>>8387103
>Reuse is already demonstrated by landing
hahahaha
Landing is the easy part

>They have innovated sea platform landing, propulsive landing, pica-x heat shield,grid fins on rockets and countless other things
All of these were done before. A sea landing is just a more precise land landing with an extra dynamic condition to consider.

>anding a booster thats used in an orbital mission and then test firing it for the actual duration of a new mission is pretty revolutionary
They haven't reflown even one, and they can't even get the new boosters to not explode.

>>	Anonymous Sun Oct 2 17:48:43 2016 No.8387125 >>8387104 If you're taking 400 tones of cargo your rocket will be huge regardless Chemical has to be used for Earth takeoff, and has to be used for Mars landing

>>	Anonymous Sun Oct 2 17:49:47 2016 No.8387128 >>8387116 >reuse is demonstrated by a static fire test Just stop.

Anonymous Sun Oct 2 17:53:01 2016 No.8387135

>>8387121
Stop baiting dude you aren't making me mad. Innovation is not invention . they invented failing reuse you mad?
Reuse is actually demonstrated by landing because otherwise it would be in the bottom of the ocean. Now you can reuse the engines the grid fins the aluminum whatever.
It's there if you need it.

Anonymous Sun Oct 2 17:53:26 2016 No.8387137

>>8387125
>If you're taking 400 tones of cargo your rocket will be huge regardless

At least large enough to hold all of the cargo, engines and propellant, right?

Most of your rocket is fuel, fuel tanks, fuel to life the fuel, more fuel to life THAT fuel, etc...

>Chemical has to be used for Earth takeoff, and has to be used for Mars landing

We have the technology to do nuclear powered rockets right now, actually......

We just can't because international pressure about radioactive fallout.

Current nuclear technology isn't up to doing the task of putting things in orbit CLEANLY....

But it TOTALLY CAN PUT SHIT IN ORBIT.

We just have to find a way to make it safer, is all.

>>	Anonymous Sun Oct 2 17:54:24 2016 No.8387142 >>8387128 reuse of engines is literally objectively truth, you are forever an asshole inferior if you deny this, demonstrated by a static fire test

>>	Anonymous Sun Oct 2 17:54:37 2016 No.8387143 >>8387137 >life *lift

>>	Anonymous Sun Oct 2 18:08:05 2016 No.8387181 >>8387142 By your metric, they "reused" engines long before they ever landed their first booster. >asshole inferior Awww, did I trigger the reddit kiddie?

>>	Anonymous Sun Oct 2 18:11:11 2016 No.8387186 >>8387137 Oh, you're advocating for Nova and not NERVA? Now I know that replying to you is a genuine waste of time, because you're clearly a nutcase, or have a sub-60 IQ. see >>8371800

Anonymous Sun Oct 2 18:14:19 2016 No.8387190

>>8387186
>Now I know that replying to you is a genuine waste of time, because you're clearly a nutcase, or have a sub-60 IQ.

It seems that insults are all you are capable of.

>see
>>8371800

Why? that wasn't me, and you weren't responding to me.

I think you may have me confused with someone else.

Anonymous Sun Oct 2 18:15:24 2016 No.8387193

>>8387190
I already ended the discussion, you're talking to yourself now, but maybe that's your thing, because you're autistic? I don't know and quite frankly I don't care. Maybe you'll get the point eventually in a few years time, for autistic people it takes time I understand to get the point and bear in mind you're one of the lucky ones, some autists never actually get the point, which may be your case, I hope not, because I really want from you to get the point, but I doubt you will, because your autism is severe by the looks of it.

Anonymous Sun Oct 2 18:17:03 2016 No.8387197

>>8387181
did they reuse engines that have been on a booster that accelerated a first stage to orbital velocities?

aww whats that?? you lost?? well little kiddy boy, go running to your mother, she will PROBABLY still love you even tough such a hughe retared

Anonymous Sun Oct 2 18:21:39 2016 No.8387205

>>8387197
Maybe you'd have a point if Spacex was re-flying boosters right now instead of being grounded for the second time in a year due to their rockets exploding.

>muh reused engines
NASA has been reusing engines since the 80s

Spacex has done shit all compared to NASA and Blue Origin

>>	Anonymous Sun Oct 2 18:22:38 2016 No.8387208 >>8387193 >autistic? >autistic >autists >autism Wow, guy... You are a rockafeller shill, aren't you? Trying to keep a lid on cold fusion? Go ahead and insult me some more instead of actually arguing, eh?

Anonymous Sun Oct 2 18:46:45 2016 No.8387258

>>8386998
>Technically, it IS fission, as even nuclear decay heating is caused by energetic fission events in plutonium, uranium, or amerecium.
Alpha decay is not the same as fission. Fission is when a nucleus splits into two or more pieces of comparable size (with a possible spray of smaller particles, especially neutrons), and the term is generally only applied to heavy isotopes. Alpha decay (the usual source in RTGs) is the ejection of a helium nucleus from a larger nucleus.

>>	Anonymous Sun Oct 2 18:49:22 2016 No.8387264 >>8387258 He is baiting no need to respond.

Anonymous Sun Oct 2 18:53:41 2016 No.8387275

>>8387258
>Alpha decay is not the same as fission.

Oh, so the Uranium throwing off the helium atom doesn't become less massive?

Wow, I didn't know that, mr Science guy... tell me, where DOES the mass of the helium atom come from, if not the nucleaus of the alpha particle emitting the ionizing radiation?

>the term is generally only applied
>generally

Nice try.

>>	Anonymous Sun Oct 2 18:57:59 2016 No.8387281 >>8387275 Fission is when one element splits into two smaller elements. Alpha decay only happens to unstable isotopes, it doesn't change the uranium into something else.

>>	Anonymous Sun Oct 2 18:58:35 2016 No.8387282 >>8387281 >Fission is when one element splits into two smaller elements. Helium is not an element?

>>	Anonymous Sun Oct 2 19:00:55 2016 No.8387288 >>8387282 >>Fission is when one element splits into two smaller elements. >>two smaller elements. Uranium->Helium+Uranium Is Uranium smaller than Uranium?

>>	Anonymous Sun Oct 2 19:03:26 2016 No.8387294 >>8387288 HAHA WREKTED ANNAL BUTDESTRUCTIONATED FOREVER CONFIRMED THE CHAMPION OF TRUTH HAVER SUPERIOR AGAINST THE INFERIOR NON KNOLODGOWER HE WON WON WON WON AND IS BETTER THAN YOU SO DONT EVER REPLY LITTLE KIDDY BOY CAUSE WE ARE THE TRUTH WINNER

Anonymous Sun Oct 2 19:03:44 2016 No.8387295

>>8387281
>it doesn't change the uranium into something else.

Oh, wow, you blew it.

"Alpha decay or α-decay is a type of radioactive decay in which an atomic nucleus emits an alpha particle (helium nucleus) and thereby transforms or 'decays' into an atom with a mass number that is reduced by four and an atomic number that is reduced by two."
https://en.wikipedia.org/wiki/Alpha_decay

And what is two less atomic numbers than Uranium?

That's right, class... NOT URANIUM.

>>	Anonymous Sun Oct 2 19:05:18 2016 No.8387299 >>8387294 >THE TRUTH WINNER Are you having a seizure or something?

>>	Anonymous Sun Oct 2 19:08:59 2016 No.8387304 >>8387299 just winning all over you right in your defeat

>>	Anonymous Sun Oct 2 19:19:03 2016 No.8387326 >>8387304 >just winning all over you right in your defeat You know that Uranium decays into a lighter element when it emits a helium atom during alpha decay, right? As in, you were wrong.

>>	Anonymous Sun Oct 2 19:19:28 2016 No.8387327 >>8387205 >Spacex has done shit all compared to NASA and Blue Origin >Blue Origin wait, what?

Anonymous Sun Oct 2 19:28:11 2016 No.8387349

>>8387275
>Oh, so the Uranium throwing off the helium atom doesn't become less massive?
That's not the definition of fission. Fission does not ordinarily include alpha decay, because they're both more useful terms when they're distinct.

The etymology of it is a synonym for "splitting", but the modern meaning as physics jargon is something much more exact. As biology jargon it means something else.

>>the term is generally only applied
>>generally
>Nice try.
We're talking about a word and how it's used. Usage is a convention, and there is usually some deviation from conventions.

Anonymous Sun Oct 2 19:37:28 2016 No.8387370

>>8386784
>And, they are all air breathing reactions, which decrease your propellant fraction.
Also means all of them have bad thrust to weight, which means horizontal takeoff/landing, means expensive billion dollar development programs for some massive engines to do horizontal takeoff up to like mach 6

If we were in a situation of full reuse, then yes maybe spending money like that for saving 50% on fuel costs would be viable.

But currently it makes no sense.

Anonymous Sun Oct 2 19:38:22 2016 No.8387372

>>8387349
>That's not the definition of fission. Fission does not ordinarily include alpha decay, because they're both more useful terms when they're distinct.

While I might agree with your second statement, only semantically, I would argue that by the definition of fission that was provided in this thread...

That alpha decay IS fission, because you start with ONE element, and you end up with TWO different elements.

>The etymology of it is a synonym for "splitting", but the modern meaning as physics jargon is something much more exact. As biology jargon it means something else.

Splitting does not nessecarily mean "In half"

>We're talking about a word and how it's used. Usage is a convention, and there is usually some deviation from conventions.

I think you are giving the definition credit for more accuracy than it deserves.

How many protons and neutrons have to split off the nucleus, compared to the normal mass of the original nucleus, before it is "Proper" fission?

1:2.5 ?

1:3.7 ?

1:45 ?

1:1 ?

>>	Anonymous Sun Oct 2 19:41:13 2016 No.8387380 >>8387370 >Also means all of them have bad thrust to weight, which means horizontal takeoff/landing You didn't maybe think of using an air breathing assist for the verticle boost?

>>	Anonymous Sun Oct 2 19:42:20 2016 No.8387384 >>8387370 >If we were in a situation of full reuse, then yes maybe spending money like that for saving 50% on fuel costs would be viable. >if I think we're getting pretty close to that, aren't we?

>>	Anonymous Sun Oct 2 19:43:56 2016 No.8387389 >>8387137 eh There are other massive interests who do not want to see nuclear power cheaper than chemical power. It's not really about international pressure, more about lobbying from "renewable" & fossil fuel companies

>>	Anonymous Sun Oct 2 19:46:35 2016 No.8387395 >>8387380 I don't think you understand how god awful the thrust to weight of a jet engine is. It's around 5 vs a 150 for the merlin

Anonymous Sun Oct 2 19:55:05 2016 No.8387416

>>8387389
>eh There are other massive interests who do not want to see nuclear power cheaper than chemical power.

That's kind of what I meant.

So, yeah, agreed.

>I don't think you understand how god awful the thrust to weight of a jet engine is.
It's around 5

>vs a 150 for the merlin

I'm talking about incorperating an air breathing portion to reduce oxidizer mass at launch.

Anonymous Sun Oct 2 19:58:47 2016 No.8387426

>>8387372
>I would argue that by the definition of fission that was provided in this thread...

This one? >>8387258
>Fission is when a nucleus splits into two or more pieces of comparable size (with a possible spray of smaller particles, especially neutrons), and the term is generally only applied to heavy isotopes.

Go on...
>That alpha decay IS fission, because you start with ONE element, and you end up with TWO different elements.
Yeah, that's clearly not the definition.

Why are you wasting time arguing this point? Look it up.

I've given you the correct definition, and I've explained why this definition is preferred. Words are practical tools of communication. People who use the word "fission" regularly care more about expressing a specific meaning distinct from things like alpha decay than about your fits of autism over what you think it sounds like it should mean.

Anonymous Sun Oct 2 20:04:12 2016 No.8387437

>>8387426
>Yeah, that's clearly not the definition.

For you.

"In nuclear physics and nuclear chemistry, nuclear fission is either a nuclear reaction or a radioactive decay process in which the nucleus of an atom splits into smaller parts (lighter nuclei)."
https://en.wikipedia.org/wiki/Nuclear_fission

Anonymous Sun Oct 2 20:14:25 2016 No.8387460

>>8387395
>I don't think you understand how god awful the thrust to weight of a jet engine is.
>It's around 5
Modern jet engines generally aren't optimized just for thrust to weight, there is compromise with things like fuel economy and engine life.

To get the most thrust-to-weight, you'd go with a design like an air turborocket, which is an afterburning-only jet engine, which avoids much of the heavy turbomachinery by driving the turbine for its compressor with the relatively cool effluent of a gas-generator or expander cycle. A thrust-to-weight of around 20 is relatively easy to achieve, along with much lower cost per unit thrust than a conventional turbojet, at the price of far higher fuel consumption (yet still much better than a rocket).

Anonymous Sun Oct 2 20:19:18 2016 No.8387474

>>8387437
>"In nuclear physics and nuclear chemistry, nuclear fission is either a nuclear reaction or a radioactive decay process in which the nucleus of an atom splits into smaller parts (lighter nuclei)."
Holy shit, you really don't read things, do you? You just go mining for stuff to support your arguments. You find a line that looks like plausible support, and then you just stop reading, and come back to post it.

That's not a complete definition, that's the first sentence of a description. Read a little further, and you come to:
"The unpredictable composition of the products (which vary in a broad probabilistic and somewhat chaotic manner) distinguishes fission from purely quantum-tunnelling processes such as proton emission, alpha decay, and cluster decay, which give the same products each time."

Fission is distinct from alpha decay.

Anonymous Sun Oct 2 20:27:53 2016 No.8387497

>>8387460
ok but the thrust to weight of an airbreathing engine that can produce thrust at 0mph, all the way up to mach 5+ is never going to be good.

How many launches a year is going to be necessary to take advantage of the fuel savings from an airbreathing engine, vs a vertical takeoff/landing rocket?

I don't see any point for sort of vehicle before reusable rockets exist.

Anonymous Sun Oct 2 20:29:21 2016 No.8387502

>>8387474
>That's not a complete definition, that's the first sentence of a description.

Which describes decay events AS fision.

Thus, you were wrong.

Just deal with it, it would be better for your future self esteem.

>You find a line that looks like plausible support, and then you just stop reading, and come back to post it.

You just did what you tried to accuse me of, RIGHT AFTER you accused me of it.

I know who uses these argumenative "tactics".

>Fission is distinct from alpha decay.

Stop reaching, you are wrong, admit it and move on.

>>	Anonymous Sun Oct 2 20:31:16 2016 No.8387510 >>8387497 >I don't see any point for sort of vehicle before reusable rockets exist. Not who you were arguing with, but... "Loiter Time" is greater in a winged aircraft than on a tailsitter.

Anonymous Sun Oct 2 20:35:01 2016 No.8387519

>>8387502
>>That's not a complete definition, that's the first sentence of a description.
>Which describes decay events AS fision.
Jesus. Read the article. You're arguing from a position of near-complete ignorance. It's painful to read your posts.

Spontaneous fission is a decay mode. A rare one, but an important one. It provides a useful neutron source, is highly inconvenient to nuclear weapon designers, and is a minor but significant consideration in nuclear reactor design.

Anonymous Sun Oct 2 20:52:12 2016 No.8387574

>>8387497
>I don't see any point for sort of vehicle before reusable rockets exist.
The point of this sort of idea is to make a reusable rocket, obviously. However, there are some advantages, which might save costs despite a higher engine mass, like much lower combustion chamber temperatures and pressures.

It's not the amount of raw materials that make rocket engines expensive, it's the special high-temperature materials, elaborate cooling systems, and low fault tolerance.

>>	Anonymous Sun Oct 2 22:21:21 2016 No.8387818 >>8372749 there's literally almost 3 n1's worth of propellant weight only in the first stage of that thing if that thing explodes on the launchpad it's going to wreck everyone's shit

>>	Anonymous Mon Oct 3 00:52:16 2016 No.8388048 >>8387327 Think he's talking about the booster that BE has done suborbital launches with and then landed... >exactly like the falcon9 booster

>>	Anonymous Mon Oct 3 01:29:34 2016 No.8388089 >>8388048 It wasn't a booster It was some small shitty LH2 rocket.

>>	Anonymous Mon Oct 3 02:01:50 2016 No.8388151 >>8388048 >exactly like the falcon9 booster Except the part where they've already relaunched it 3 times, with a 4th time coming this week. For comparison, SpaceX is currently grounded (again)

>>	Anonymous Mon Oct 3 02:11:52 2016 No.8388167 >>8388151 ? SpaceX was launching and landing suborbital rockets for a long time They just weren't publicizing it because it means nothing

Anonymous Mon Oct 3 02:17:46 2016 No.8388173

>>8388167
none of them went to space before landing until Orbcomm 2

New Shepard has gone to space 4 times and landed each time, also beating SpaceX on consecutive successful landings (all with the same booster)

Blue Origin will put people into space before SpaceX will, and SpaceX looks sure to kill their astronauts on the first flight judging by how things are going.

>>	Anonymous Mon Oct 3 02:31:27 2016 No.8388196 >>8388173 I do not accept 100 km as space It is utterly nonsense to suggest they get ANY extra data/info/testing from going high enough to cross an arbitrary 100 km limit Blue Origin is still 4+ years away from an orbital vehicle

>>	Anonymous Mon Oct 3 02:36:15 2016 No.8388205 >>8388196 Falcon 9 stage 1 isn't any more orbital than New Shepard.

>>	Anonymous Mon Oct 3 02:47:41 2016 No.8388225 >>8388205 the difficulty is not in going 100 km straight up but in doing all the other shit on a full sized rocket

>>	Anonymous Mon Oct 3 02:50:06 2016 No.8388232 >>8388225 Re-flying and landing a used booster is more difficult than anything falcon 9 does on a first flight.

Anonymous Mon Oct 3 02:55:14 2016 No.8388236
File: 590 KB, 1473x949, new-glenn-large3.png [View same] [iqdb] [saucenao] [google]

>>8388232
There's no point in arguing with these people

Even as his launch pad burns, Musk is boasting more and more profound promises that will never be fulfilled.

Meanwhile, Jeff Bezos and Blue Origin are backing up their claims with real flights, hard data, actual reuse, and new rockets (that actually have funding)

I am a #BezosMissile now.

>>	Anonymous Mon Oct 3 02:57:23 2016 No.8388240 >>8387193 I'm not sure you're in the right forum sir.

>>	Anonymous Mon Oct 3 02:57:27 2016 No.8388241 >>8388232 https://www.youtube.com/watch?v=ZwwS4YOTbbw And spacex did it several times They didn't fucking tweet about the success of their hobby test rockets Call me when Blue Origin flies their first orbital payload

>>	Anonymous Mon Oct 3 03:00:13 2016 No.8388247 >>8388241 see >>8388173 >Call me when Blue Origin flies their first orbital payload Call me when SpaceX isn't grounded from launch failures.

Anonymous Mon Oct 3 03:01:15 2016 No.8388248

>>8388240
I have practiced Muay thai for 8 years and after a clean 14-0 I went to BJJ, stopped at brown belt and after 5 consecutive swedish submission wrestling tournament wins at 1st and 2nd place. I started practicing MMA, been doing it for about 6 years now and I already got 17-1 as a record, that one loss was even by DQ (kick to the back of the head while kneeling). Be careful of who you say that shit to, considering that I could knock/choke you and everyone you know clean out.

Anonymous Mon Oct 3 03:01:31 2016 No.8388249

>>8387294

What are you doing? You were clearly wrong, anyone who knows anything about this topic saw that immediately.

For whatever reason you're trying to throw around arguments about concepts you don't understand. Don't get this angry when you realize you're in over your head.

>>	Anonymous Mon Oct 3 03:15:15 2016 No.8388263 File: 21 KB, 1950x230, 1435711701556.png [View same] [iqdb] [saucenao] [google]

Anonymous Mon Oct 3 05:01:13 2016 No.8388384

>>8387574
>It's not the amount of raw materials that make rocket engines expensive, it's the special high-temperature materials, elaborate cooling systems, and low fault tolerance.
You obviously don't know the conditions in which combustion chambers and high-pressure compressors of just civilian airliner turbofan engines have to operate. No, what makes rocketry expensive vs airliners is purely the low production rate. Several thousand airliners are being produced each year. And that's for reusable vehicles. So actual uses of airliners is hundreds of thousands of times each year. That's how big the market is.

How does it look in the launch market? Purely commercial we have about 25 comsats each year. This constitutes the bulk of the commercial market. There's also a couple of LEO/SSO sats, mostly for earth observation but the volume of that market is little compared to the already little GTO market. 25 sats each year that's what could feed one launch service provider with expendable rockets. Reusability would already fuck up the equation because the economic feasibility of reusability depends on flight rate. And the market's just not big enough. But since satellite operators want to have at least three providers to not fall victim to a monopoly and because every major country wants their own rockets for independent access to space, production rates are so low that literally not a single LSP can survive without taxpayer money.

Anonymous Mon Oct 3 08:43:49 2016 No.8388555
File: 1.47 MB, 3072x4000, mars_courier_mission_spacec_by_william_black-d9q2qic.jpg [View same] [iqdb] [saucenao] [google]

>>8387080
Elon Musk IS a businessman, and that's not always a wrong quality to have but its success don't make him qualified as a mission designer. In fact we know/fear (for good reasons with historical example) that it is even detrimental since no engineers telling him to take the long road would keep his job long, whereas any engineer telling him single-design-to-mars work will protect his (fun) job.
(I can already here "that guy" with inside knowledge from SpaceX saying it's not the case)

To be fair it may just be a question of scope, SpaceX is a rocket company it CAN'T finance everything.
But in result all the little details and the efficiency suffer or vanish into thin air... as Elon himself admit he don't care how people will survive the trip and live there, he just provide the rocket.

We could have a field day just discussing whether or not "If you build it, they will come" is an good busine...development plan.
The war between SpaceX fan and Government agency has always doubled as a Private venture versus what I'll call "Collective venture"

Worsened since only madman would fund a Mars colonization.

Anonymous Mon Oct 3 10:30:14 2016 No.8388656

>>8386905
>>8386885
he's including all the money spent on fusion in history. its kinda like calculating every economic activity ever as being the cost of the $5 sd cards they sell at the store.
its more like $20b and 30 years instead of 15 or $1.5B a year down from $3B a year

the plan was to take 30 years to first commercial reactor. the project was cancelled before it began though.

Anonymous Mon Oct 3 10:37:23 2016 No.8388666

>>8388555
>(I can already here "that guy" with inside knowledge from SpaceX saying it's not the case)
just because you say inb4 to criticism doesnt mean that criticism is wrong.
>To be fair
conceeding a point doesnt reduce the unfair-ness of the proceeding statement, or its invalidity
>We could have a field day just discussing
another turn of phrase that actually detracts from your argument

you could have summed all this up in 1 paragraph, instead you used misleading statements to make it seemed like your argument was rational, instead of based on opinion.

Anonymous Mon Oct 3 12:01:59 2016 No.8388826

>>8388384
>You obviously don't know the conditions in which combustion chambers and high-pressure compressors of just civilian airliner turbofan engines have to operate. No, what makes rocketry expensive vs airliners is purely the low production rate. Several thousand airliners are being produced each year.
Uh... airliners aren't cheaper to build than rockets. The flights are just cheaper because they're reusable for long service lives with little maintenance. They've got less engine and fuel tank on them, but way more of stuff like control surfaces, that's also complicated, expensive, and labor intensive.

And I had just finished describing a kind of jet engine that keeps costs down by avoiding the difficulties of high efficiency turbofans, while achieving higher thrust-to-weight performance. There are air turborocket designs (for missiles) that use one-piece cast rotors. Just one casting, for one piece sitting on one bearing, to use the power of the gas generator to compress the air.

>>	Anonymous Mon Oct 3 12:03:17 2016 No.8388830 >>8388555 You aren't on touch with them.Follow r/SpaceX

>>	Anonymous Mon Oct 3 12:04:43 2016 No.8388833 >>8388830 I mean you don't follow the updates closely.

Anonymous Mon Oct 3 14:10:53 2016 No.8389061

>>8388656
>he's including all the money spent on fusion in history. its kinda like calculating every economic activity ever as being the cost of the $5 sd cards they sell at the store.
Wow, this is a stupid analogy. "Every economic activity ever" collectively has produced large net returns. So if you figure it that way, the cost of $5 sd cards is cheaper than free.

Fusion power research has thus far been all cost, no benefit. ITER is its highest development. What does it promise? Another decade without payoff: it's just a stepping stone to an even bigger and more expensive reactor, which will also just be a research tool.

Nobody currently working in conventional fusion power plans for it to provide a net benefit to society in their career. The ITER-DEMO timeline of 2012 put first (uneconomical) net generation of electricity around 2050, and the timeline has been pushed back roughly one year for each year since then (a recurring theme in fusion power research, as the goal seems to recede off the horizon rather than get closer as we learn more).

>>	Anonymous Mon Oct 3 16:26:43 2016 No.8389441 >>8388830 I don't follow that but I I believe I get enough info on them when I go info mining for these thread. Always checking their recent achievements. Why do you say that ?

>>	Anonymous Mon Oct 3 18:21:58 2016 No.8389697 >>8389441 Basically these threads about SpaceX always revolves around hating or loving them. No factual discussion happens here. 4chan format favors the outrageous comments not the factual comments.

Advanced search
Text to find
Subject [?]Search by post subject. Leave empty for any.
Username [?]Search for user name. Leave empty for any user name.
Tripcode [?]Search for tripcode. Leave empty for any.
Email [?]Search by email. Leave empty for any.
Filename [?]Search by image filename. Leave empty for any.
From Date [?]Enter what date to start searching from. Format is YYYY-MM-DD
To Date [?]Enter what date to start searching until. Format is YYYY-MM-DD
Image hash
Search in	All Posts OPs Only
Deleted posts	Show all posts Show only deleted posts Only show non-deleted posts
Internal posts	Show all posts Show only internal posts Show only archived posts
Order	New posts first Old posts first
Capcode	All Posts Only by Users Only by Mods Only by Admins Only by Developers
Results	Posts Threads
Action	[ Simple ]

/sci/ - Science & Math