/sci/ - Science & Math

Chemical rockets are such trash to be honest-crdit to everyone for optimizing them despite the absolute shit-tier energy density of the fuel but come the fuck on. We NEED fusion powered upper stages. Musk should quit fuck-cunting around and see about buying off MSNW, their tech looks promising. https://en.wikipedia.org/wiki/Nuclear_pulse_propulsion#MSNW_magneto-inertial_fusion_driven_rocket He should also throw a few bones at that Helion energy fusion power offshoot-i'm sure martian water has shitloads of deuterium in it, and that' a lot easier to harvest than having to hunt down uranium.

>>11054301
This stuff can wait until after Starlink makes SpaceX Amazon tier. This is still essentially the prologue days. One Starship lands on the moon things will have started.

have a webm on Alexei Leonov: >>>/wsg/3085419

>>11054241
Earth is flat

Starship de geso~

>>11054301
Fusion is still a way off.
Iter is the SLS of Fusion energy. It might get the job done eventually, but it's outdated in terms of tech and inefficient in terms of time and money investement. The fusion startups meanwhile all have slightly different approaches. Most promissing is probably Tokamak Energy and SPARC, but they're still just startups so who knows if they're actually gonna pull through. Other startups just throw unproven technologies at the wall and see what sticks.
I don't even know if anyone is looking into making a fusion drive before we have a proper power plant running. Although I don't know enough about fusion drives to say if it actually depends on the proper reactor technology getting completed.
However I do know a fusion reactor with our current designs is too heavy to put into space, especially if you consider shielding.
Also I don't know if it's a good idea to put ridiculously powerful magnets on board of a spacecraft.
Meanwhile inertial confinement fusion with lasers turned out to be a meme.

US military recently patented compact fusion reactors because those recently acknowledged UFO videos look terrifyingly like the Chinese already have something like that. At least that's what I've heard.
Is fusion propulsion close?

Conquer the solar system.

>>11054530
>patented
literally meaningless.
>because those recently acknowledged UFO videos look terrifyingly like the Chinese already have something like that
Whatever that was, it sure wasn't a chinese fusion powered anything.
China is still pouring billions into big, clunky fusion research reactors. And no that shit is not a smoke screen. No, a tiny secret project did not crack fusion willy-nilly.
If they did, all their citizens wouldn't choke to death on coal and wood exhaust.
And I don't think our hypothetical fusion drives even work properly in atmosphere anyway.
Also if you suppose the tictac stories actually checked out, there are other problems with how you could even move and accelerate anything that fast in atmosphere. Also you can't see a fusion propulsion system on it. You can't see any propulsion system on it. It's just a few pixels of tictac with a tall tale attached by a handful of people.
>At least that's what I've heard.
Great source, famalam.
>Is fusion propulsion close?
No.

>>11054558
>If you think those stories check out

There is literal documented video, radar, ir, etc... Proof of objects performing manuevers that should rip them apart. People always rip on flat earthers for not believing space pictures, how the fuck is this any different?

>>11054582

They are real. They aren't Chinese nor are they powered by fusion.

So how come the Russians haven't replaced the Souyz? Or at least developed a replacement and then cancelled it because it is too expensive like .most of their post soviet military tech.

>>11054630
Money.

>>11054558
Here you go:
https://www.thedrive.com/the-war-zone/28729/docs-show-navy-got-ufo-patent-granted-by-warning-of-similar-chinese-tech-advances

I know patents are meaningless, especially in the US. Let me quote from the article:
>But then the Chief Technical Officer (CTO) of the Naval Aviation Enterprise personally wrote a letter addressed to the examiner claiming that the U.S. needs the patent as the Chinese are already “investing significantly” in these aerospace technologies that sound eerily similar to the UFOs reported by Navy pilots in now well-known encounters.

I was also talking about the (I think) Iranian UFOs, not the Niemitz one.

>>11054630
>>11054637
Actually, they are developing a replacement for both the rocket and the capsule: the Soyuz-5 rocket and Federation capsule.

>>11054674
When Commercial Crew flies ruskis will lose their primary source of income and Federation/Angara will be in development hell for rest of eternity, i hope you like soyuz launches!

>>11054490
That's a squid girl, retard.

Where are the Long March 5 launches?

>>11054301
>uranium
that's dumb shit for weapons, what you need is Thorium

>>11054716
News came out yesterday that it will be launched in December. The components were seen being shipped to the launch site.

>>11054558
>>11054558
>patenting a device with no prototype or proof of concept
US Gov patents aren't bad, unless it is the patent for the epipen where the government gives exclusive manufacturing rights to the daughter of a senator who increases the price 500%.

>>11054725
On one hand you have the patent for a device that a small percentage of the population needs. On the other hand you have a device to produce unlimited clean energy from fuel that costs almost nothing.

Nah surely the US government won't abuse it if turns out to be legit.

>>11054674
>Single stick
It looks so...plain.

>>11054821
Maybe Angara is more to your taste?

>>11054241
add the /sfg/ in the subject next time. why cant anyone in this general make a fucking OP right

>>11054978
You know the first rule of being OP.

>>11054978
>why cant anyone in this general make a fucking OP right
because 99% of the people here are reddit invaders

>>11054449
>after Starlink makes SpaceX Amazon tier
lol

>>11054997
>*laughs in original Iridium constellation*

>>11054449
>>11054997
>*laughs in original Iridium constellation*

>>11054582
If the thing were real and it accelerated as fast as it is claimed to have done it would have produced an enormous sonic boom and heated itself to incandescent temperatures by flying at hypersonic speeds through a thick atmosphere. Even if it had a magic shield to protect itself from direct heating of it's surface it would have created a bow shock of superheated air. Next, if it were using fusion for propulsion it's exhaust would be a flashlight beam of lethally intense neutron radiation and it would generate a blinding like the flash of a nuclear bomb except persistent. It would also have to radiate an enormous amount of heat, which would be transferred to the atmosphere around it causing a thermal bloom not seen in the brief video. Honestly the way the screen flickers and fuzzes at the end I'd guess it's a computer glitch, if it isn't though it's a vehicle which can arbitrarily ignore the mechanics of reality and we're only going to learn about the pilots if those pilots want us to, or they could accelerate their indestructible craft through the planet at relativistic speeds and kill us on a whim.

>>11055119
You don't get "a computer glitch" to explain tracking on multiple different and independent targeting systems, ranging from an Arleigh Burke to an F-18's radar. The claimed acceleration and lack of visible exhaust ruled out ordinary propulsion long ago.

So did the Chinks buy it up?

>>11055124
I haven't gone over a ton of it, but hey if all the claims are true then at least we have learned a few valuable things. (ASSUMING) the thing is real and not bullshit we know that a ridiculously efficient reactionless drive can be made, we know that there is some method which can be used to avoid the normal issues of hypersonic flight, a combination of indestructable hull and somehow not disturbing or heating the air around them.

>>11055126
I seriously doubt anyone brought it for the plane, they probably just got the RnD data cheap to see if they found anything interesting.

>>11055126
Two bros chilling in an airplane, 120 feet apart because they're not gay.

>>11054490
The virgin comparing starship to something weebish vs the CHAD comparing it to the one lego set you had memories of

>>11055308
Holy shit. I remember seeing this exact set in the store and being sad because my parents were poor and I'd never have it.

>>11055308
uh...

>>11055319
I got to have it as a Christmas gift once, sorry you couldn't get it man.

>>11055329
>buy a simple SLS lego set
>takes a decade to complete
>in the meantime some african-american kid gets a super complex monstrosity of a rocket lego set
>he completes it in a couple of months while sitting in his field
>it even has chrome bricks

>>11055336
Is this a metaphor for Jews giving more to blacks than whites?

>>11055336
Holy shit I'm retarded, I get it now.

>>11055342
>forgetting that Elon is from South Africa
>forgetting that he has American citizenship too
>forgetting that this technically makes him an african-american

>>11055347
See this:
>>11055346
Still
>mfw elon musk is technically black

>>11055126
>>11055336
>>11055347
>>11055372
Fuck off, racists.

>>11055376
How was >>11055336 racist?

>>11055376
Fuck off, Reddit

>>11055382
He's a numale, his brain is gonna 404 once he fails to find an actual reason this is rayciss, and why racism as a whole is really bad.

>>11055393
Alright, back to the scheduled shitposting then.

>here's your Artemis lander, bro

>>11055423
I’m looking forward to SpaceX attempting to land on the Moon and failing repeatedly because Starship is horrendously unoptimised for it. Currently, it looks like Blue will be the king of cis-lunar space if they can get launching to orbit in a timely fashion.

>>11055423
Is there any rule in the bidding that says they can't do this?

>>11055444
Starship is optimized not just for landing on the Moon, but for landing hundreds of tons of cargo on the Moon.

Same with Mars.

Yours is the same mistake as Zubrin makes. The age of tiny tin cans ought to be over. As if the goal is to land few people on the surface, plant a flag, and then do nothing else. SpaceX as a whole would be a failure if that is all that happens.

WHEN'S STARLINK?
H
E
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,
S

S
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>>11055452
the expectation is that the landers will be launched on SLS I think, although if commercial options are allowed then it should be kosher

>>11055456
>Starship is optimized not just for landing on the Moon, but for landing hundreds of tons of cargo on the Moon.

The delusion is strong in this one...

>Yours is the same mistake as Zubrin makes

What, we both have functioning brains?

>>11055461
It’s been delayed

>>11055476
No, the landers will be launched in multiple pieces (ascent module, descent module, transfer stage) on commercial launch vehicles and assembled in Lunar orbit. SLS is an option for providers, but I don’t think anybody will use it because of the 2024 deadline.

>>11055456
>The age of tiny tin cans ought to be over
But you're forgetting that highly specialized and small tin cans will allow for the maximum amount of budget to be funneled to key states for the least amount of actual work. Spaceflight isn't about flying in space, it's about keeping jobs available and money flowing. Totally, I swear.

>>11055483
No, you use antiquated "let's never go beyond small modules" cuckoldry.

>>11055476
>the expectation is that the landers will be launched on SLS I think
Nah. Nasa is happy if they can even cobble together the three cores in time to launch the demonstration mission, the gateway module and the actual mission. Everything else is commercial rockets.

>>11055483
Not who you're replying to, but what about Starship that makes it not good enough to be used as a lunar lander?

>>11055503
he might be complaining about bringing aerofeatures down to the lunar surface, which is a fair complaint
if you're willing to do cargo transfer in LLO then a dedicated striped down Starship based lander might be better, but you're going to be racking up hours on that engine over time and your options are microgravity maintenance or maintenance on the lunar surface, neither of which sound appealing to me

>>11055521
>your options are microgravity maintenance or maintenance on the lunar surface, neither of which sound appealing to me
maintenance on the lunar surface may be preferable as the gravity will keep all the parts still rather than slowly drift away from each other. Just be sure to pave a large area and keep it clean of lunar soil.

>>11055524
the lunar soil fucking electrostatically levitates and if anything is moving at all you're going to get that dust moving

>>11055444
Doesn't have to land - just ferries the lander there and back. No?

>>11055503
>Raptor is too powerful and can’t throttle deep enough, so that means the only way to land on the Moon is a deadly last second suicide burn, instead of the controlled powered-descent all lunar landers have used.

>It uses Methane as fuel which can’t be generated by ISRU on the Moon, unlike hydrogen. So if you want to land somewhat large payloads on the surface your not coming home...

>Anybody who knows how the Moon’s regolith works will tell you that an engine as powerful as Raptor will dig a large crater and sandblast everything for miles with Moon dust travelling at escape velocity.

>It’s way too tall and skinny to land on a body with such low gravity, it’ll likely tip over if it makes it to the lunar surface intact. Which is why all previous landers have been so squat in design (a low centre of gravity is important). Also, there’s the God awful leg design which doesn’t inspire much faith in regards to stability...

>>11055541
That’s Zubrin’s idea, but Starship is supposed to be the Moon lander. I think it will be unsuccessful and therefore, agree with him.

>falling for the NASA hoax

>>11055541
Starship, while perhaps not suited for long term use as a lunar lander, is perfectly workable in the short term if you need a lot of tonnage on the surface for cheap
to improve over Starship in the $/kg department requires lunar ISRU and enough of a presence on the surface that basic on-site maintenance of a permanent lander like Blue Moon isn't overtaxing the infrastructure
the big advantage of Starship is that it goes up, drops the stuff, then returns to Earth and can be serviced
it requires neither service nor fuel on the moon, perfect for low infrastructure cases
Blue Moon is much more forward thinking
>>11055563
hoverslams aren't an issue
it can bring all the fuel it needs to return with it, even with the maximum single launch LEO payload, and if you fuel it with LOx on the surface it becomes very much cheaper with regards to orbital refueling
cis-lunar space and the lunar surface is going to be absolutely uninhabitable for hours after a Starship landing without serious landing pad infrastructure, you're right

https://www.businessinsider.com/elon-musk-spacex-boca-chica-village-private-meeting-buyouts-2019-10

>Musk apparently also described a long-term plan to move away from land-based launch pads and instead use offshore platforms near Boca Chica Beach to fly Starship with less risk to the ground.

>"He mentioned that they have to take off right offshore, but they have to land somewhere, right? And you can't do that on land in the middle of Paris, I think he said," Mrs. Pointer recalled. "So you have to have offshore facilities everywhere."

>Residents say SpaceX has not only extended its buyout offer deadlines, but also dispatched an appraiser to more fully evaluate their homes and consider properties in coastal areas. If those assessments come back with a more fair valuation, multiple residents who initially said they'd decline the deal told Business Insider they would reconsider selling to SpaceX.

>>11055579

>hoverslams aren't an issue

One on the Moon will be a lot scarier than one on earth l, you’ll be travelling a lot faster and igniting a lot closer to the ground. There’s also the question of accuracy, SpaceX uses GPS for Falcon but there isn’t any on the Moon. NASA are using LIDAR, so that’s an option but is it accurate enough for a hoverslam?

>it can bring all the fuel it needs to return with it, even with the maximum single launch LEO payload, and if you fuel it with LOx on the surface it becomes very much cheaper with regards to orbital refueling

I’m not going to debate Starship’s performance with refuelling because key factors effecting it such a as dry mass seem to still be in flux.

>>11055563
>It uses Methane as fuel which can’t be generated by ISRU on the Moon, unlike hydrogen. So if you want to land somewhat large payloads on the surface your not coming home...

It is not so clear. Volatiles on the Moon possibly include frozen CO2 and methane along with water. More importantly, most of the propellant weight is in oxygen. Refueling in orbit and then merely refueling oxygen on the Moon enables Starship to land 100+ tons of payload and return back to Earth.

>Anybody who knows how the Moon’s regolith works will tell you that an engine as powerful as Raptor will dig a large crater and sandblast everything for miles with Moon dust travelling at escape velocity.

This is very much a solvable issue and an issue that has to be solved anyway if you want to be serious about landing large payloads on the Moon.

>It’s way too tall and skinny to land on a body with such low gravity, it’ll likely tip over if it makes it to the lunar surface intact.

It will only tip over if it lands on VERY uneven ground. Most of the weight is in the engines at the bottom of the rocket, which makes the design very stable. This is not a real issue assuming you do not mistakenly land on a very steep slope.

>>11055563
>Raptor is too powerful and can’t throttle deep enough

Use methalox RCS for final landing?

SpaceX Florida site.

https://www.youtube.com/watch?v=DTHxo9Uu6Oo

>>11055626
I would heavily advocate for this, but I haven’t heard or seen any references of it by SpaceX. Also, this depends on the size and power of such thrusters.

>>11055592
if you don't think you can do the whole hoverslam at once from orbital velocity (you can't, you're right) it necessitates divying up the final decent/braking burn into two: one with the vacuum engines at perilune a kilometer or so above the surface or whatever in your final descent orbit, and the hoverslam with the sea level engines. After the Raptor Vacuum burn there's no going back, and the hoverslam MUST work or you're crashing on the surface, which is the same issues you have on Earth. Claiming that Starship can't land on the moon is saying that Starship can't land on Earth either.
some horrible back of the envelope calcs:
Apollo lunar descent orbit had a perilune of 15000 meters, and assuming an instantaneous burn dropping the velocity relative to surface to zero, you would hit the lunar surface after 136 seconds travelling at 220 m/s, which is only around three times faster than the hoverslam burning required for Earth landing

>>11055444
Even if the first starship crashes on the moon i would still find this a enormous achievement.
Getting that much mass too the moon is no easy feat.

>>11055701
>Claiming that Starship can't land on the moon is saying that Starship can't land on Earth either.

I’m not saying it’s impossible, just incredibly dicey and massively inferior to a controlled descent in regards to landing on the Moon, due to the many factors I’ve listed. Personally, as a passenger, I wouldn’t want to ride something that lands via hoverslam, especially on the Moon. Controlled descent, plane-style horizontal landing and traditional parachutes all seem like far more attractive and less anxiety inducing ways to land spacecraft.

>>11055563

Define large lunar payloads. Doesn't Starship get at least 30 metric tonnes to the surface?

So a payload greater than that?

When is this payload supposed to exist? Does Starship provide sizeable lunar surface payload capability good enough for the next century or more?

When is some alternative 30+ lander supposed to exist, and lunar fuel production facilities, and for what cost?

Stockpile fuel on the moon surface for return for these uber rare payloads or one way trip it.

>>11055655

I think there was some comment recently by Musk that they'll switch to methalox RCS at some point for its better ISP, which will allow them to avoid using raptors for some portion of the landing sequence.

>>11055788

Starship IS the payload. 1000m3 of pressured space.

Every Starship that lands on the Moon is a lunar base.

>>11055783
I'm sorry but hoverslam is the most efficient method get fucked

>>11054301
not sure how up-to-date u are on science n all, but fusion doesn't exist yet, desu

>>11054630
because they aren't retarded unlike nasa

>>11055808
Yes, it’s more fuel efficient than hovering and therefore, superior for landing uncrewed vehicles (e.g. boosters) due to reduced payload loss. But for landing people, it’s scary.

>>11055829
triple redundant landing engines, m8
your paranoia won't stop SpaceX

>>11055483
yes good goyim keep using only small landers

The spaceship should not be landing anywhere, it is trying to be adept at too many tasks (landing on the moon/mars and earth) if it needs to be refuelled in space it may as well stay there and use a smaller rocket to shuttle passengers to it with a specialized lander detached on arrival at the destination. Pretty sure that direct landings to the moon are incredibly delta-v expensive which is why apollo didn't use that method.

>>11055837
I mean Hopper’s first 150m attempt proved that Elon’s definition of redundant is sketchy to say the least. My paranoia won’t stop SpaceX, but the ground definitely will....

>>11055847
You don’t need to build small, just something more optimised for the Moon.

>>11055861
Mr Zubrin, it’s an honour to have you among us!

>>11055871
virgin everyday reddistronaut versus chad dr "frogposting faggot" zubrin

>>11055871
very well thought out and detailed reply, where did you get your aerospace degree?

>>11055865
>I mean Hopper’s first 150m attempt proved that Elon’s definition of redundant is sketchy to say the least
You know that the Hopper only had one engine, right?

>>11055861
I actually agree. Starship can bring over a hundred tonnes to LLO. Why wouldn't you bring a hydrolox lander you can refuel on the surface? Why would you bother landing your heatshield and Raptors?

>>11055861
>Pretty sure that direct landings to the moon are incredibly delta-v expensive which is why apollo didn't use that method.
True, but orbital refueling and ISRU gets around that issue.

>>11055881
I don't really know what they were trying to accomplish with hopper

posted on r/spacex

>>11055861

Some refueling and using more fuel, supplied by Starship tankers = cheaper than optimized hardware, at least for now. Hardware dev is expensive.

Fuel is cheap as fuck in Starship world.

Apollo was launching on a single expensive booster with capped capacity. All the twists and turns were to make it fit. The Starship way deconstructs Apollo and says why don't we throw uncapped mass through many cheap launches at the problem.

>>11055877
I was just acknowledging that he’s basically made the exact same point Zubrin did when talking about Starship in regards to the Moon, no need to get snarky.

>>11055886
Starship can’t do ISRU on the Moon

>>11055888

Why am I such a brainlet and find this so hard to understand

>>11055894
It’s not exactly a simple design tbf, doesn’t seem realistic for something supposed to be transported to Mars.

>>11055888
A lot of effort and a lot of good content went into this but zero skill in graphic design. I can read and understand it but I had to sit for a few minutes and follow the lines back.

>>11055894
>big fuck off compressors turn martian atmosphere into compressed co2
>big fuck off drill mines water, electrolysis splits water
>oxygen taken for oxidizer, hydrogen goes to the sabatier drums
>sabatier reaction is exothermic so he's plopped a heat engine in the middle for efficiency gains
>hydrogen and carbon dioxide go in, heat and methane (and leftover carbon dioxide and some other stuff, hopefully not pieces of catalyst) come out

>>11055896
It's a simple design, it's just not a simple drawing. No more complex than a big HVAC system. The trouble is working at 400° without maintenance or catalyst degradation for years before humans arrive.

>>11055893
Starship can ISRU oxygen and bring extra methane, most of it's mass is oxygen. Not as efficient or effective as full Martian ISRU, but good enough.

>>11055906
>No more complex than a big HVAC system
So MechEs have a chance to go to Mars?

>>11055924
Absol-fucking-lutely. Early Mars will be 20% scientists and astronauts, 80% mechanical engineers and tradesmen trying to keep the air clean, water and methane flowing, keep the hydroponics online, etc. Once there's a large enough population you'll get some enterprising chucklefucks trying to sell pizza to all those engineers. The first private pizza stand on Mars is the true keystone of colonization.

>>11055888
>Power generation
>Shows shithouse kilopower unit

Why are Redditors obsessed with this piece of junk?

>>11055886
paying for it is not getting around it.

>>11055953
Because it’s either that or shitty solar panels, (Opportunity says hi btw)

>>11055953
Reddit is insisting that there's absolutely no reactor that could fit on a Starship and provide enough power for ISRU. Unfortunately, many people interested in space are only interested in space, and don't really realize submarines have had reactors for half a century.
>b-b-but muh coolant
A valid concern in space, but on Mars you can just sink all that heat into the ground through a big ol' bank of Stirling engines.

>>11055959
It is when you don't throw your refuelling vehicle into the ocean.

>>11055962
submarines are fucking huge

>>11055964
Expendable nuclear submarines?

>>11055893
Funny I didn't know about what Zubrin said yet made the same observation. If even a layman can see it then perhaps Zubrin has a point?

>>11055964
my point is it is even cheaper if you don't use direct landing so why do it? It's just a waste.

>>11055965
So is Starship

>>11055969
[loud Soviet anthem noises]

>>11055962
This >>11055965 and stirling engines are also really big and heavy.

>>11055978
>tfw you remeber Kursk
i'm 27 and I feel old. I remeber all sorts of late 90s/early 00s events that zoomers don't have a clue about. Fuckers don't even know crazy frog.

>>11055962
I think you underestimate big and heavy Submarines are. For example, it takes 80 gallons of just water to cool a submarine reactor, that doesn’t include the weight of the reactor itself. Starship has a payload of 150 tons...

>>11055971
https://twitter.com/robert_zubrin/status/1178724273025933312

Enjoy the butthurt below...

>>11055982
*how

>>11055965
But their reactors are comparatively small and still put out hundreds of megawatts of power, a spacecraft reactor need not even be that size, maybe just enough for 50-100MW will be more than sufficient for pretty much any forseeable function. Perhaps much less, perhaps just 10MW. It's also wrong to assume that PWRs are the only usable nuclear reactor, MSRs are superior in basically every way except for coolant expense, but that's because an MSR's coolant is also it's fuel.

>>11055982
>80 gallons
you mean tons?

>>11055990
Shit, yes

>>11055982
This is why i dislike the SpaceX fanbase. Zubrin isn't even trashing starship he's actually supporting it and offering ideas to make it better but he's shouted down just because it goes against the company line. They just lap up whatever fantasy Musk gives them, the mental gymnastics to justify landing starship on the moon is painful to see. All because "it looks like sci-fi!"

>>11055989
It's not about size it's about weight. In any case there are significant legal hurdles to putting anything nuclear in space let alone even sourcing it.

>>11055975
So that you can get over a hundred tons of material rather than a tin can with two dudes and a toy car.

>Using multiple small landers, each of which has to burn back up to starship multiple times to get it's payload to the ground
>Not just landing starship

For what purpose

>>11056008
>bringing your heatshield, all your tankage, sea level raptors, raptors in general (they'd probably land starship on the RCS because the raptors are too powerful)
>or bring one hydrolox landyboi

>>11055883
>Starship can bring over a hundred tonnes to LLO. Why wouldn't you bring a hydrolox lander you can refuel on the surface?

And transfer cargo from Starship to your lander in LLO? Sounds more complicated than just landing the whole sheband on the surface.

>>11056012
But starship doesn't need refuelling. It gets refueled in orbit and can land and come back with 100t on a single tank. If you have a landing site you are just adding complexity because muh oldspace tin cans.

>>11056005
so now you want to optimize starship as a moonbase in addition to LEO launcher/moon lander. Fuck man, may as well use a Tardis at this point.
>>11056008
You would only need one lander to bring the payload because the payload is only a small fraction of starship. A couple people, a few moonbase parts, it's just a few tons.

>>11055994

Except that Zubrin did not make any actual argument. He is just stuck in the OldSpace thinking that lander has to be a small tin can. Well, it does not. You need huge landers to establish a real colony. So you may as well use a whole Starship.

Zubrin is well known for his hugely optimistic size and mass estimates for a Mars mission, too. This is just more of the same syndrome.

>>11056024
>optimize starship as a moonbase

It can land on the moon and is a pressurised vessel, congratulations it's already a moonbase.

>A couple people, a few moonbase parts, it's just a few tons

So instead of using its 100+t capacity you are sending it there with a few tonnes and a lander to stage off it. Good thing you aren't in charge.

>>11056024
>couple people, a few moonbase parts, it's just a few tons.

This is not how you establish a real moonbase. We need hundreds of tons of useful payload. Good luck landing that using small landers efficiently.

>>11056014
Because you will massively reduce the payload compared to just leaving it in LLO.
>>11056019
The orbital refuelling was to get it to the moon. A direct landing would need even more fuel, where is this coming from?

>>11055997
Your valid point has to do with legal hurdles, but any significant power supply will be heavy, 10MW worth of solar panels would weigh nearly as much if not more due to their comparatively poor power efficiency. Lifters will simply have to enlarge to cope with the lifting necessity, which they absolutely can.
>>11056008
The primary concern of critics seems to be that the Raptors might not be sufficiently flexible in throttling capacity to land without digging a crater or blasting out dust at super high speed which could damage the vehicles. The fix which is most obvious to me would be to put vacuum optimized vernier rockets up near the nose of the vehicle to carry it down for the final few seconds. Such a problem would be resolved in later landings by the construction of a smooth elevated landing pad.

>>11056024
>A couple people, a few moonbase parts, it's just a few tons.

Except that is not what Starship is designed or at all. The goal is something much bigger. Pic related.

>>11056044
The full refuel gets it to the moon and back with a direct landing. This has been said many times.

>>11056049
Or if it's possible to use lunar ISRU to make a pad, you just stage small landers initially and then once your pad is built, toss them in trash.

>>11055989
I dont think you realize just how much 10MW is. That can be used for absolutely anything you could power a small town of 1,000 people with that for an entire year. Not to mention if you are doing space missions and need to be energy conservative? easily 10,000. You aren't using electricity like in a submarine to generate thrust you are using it for mainly life support, communication, and engine vectoring.

>>11056044
>A direct landing would need even more fuel, where is this coming from?

1. Fully refuel in high elliptical Earth orbit (minus some oxygen)
2. Land on the Moon, deploy 100+ tons of cargo, refuel oxygen from ISRU
3. Return Starship directly to Earth

>>11056057
In fact thinking about it, I'm wondering if you even need a pad. Get a bunch of sheets of a few mm sheet metal, weld them together and land starship on that. It would be a nice flat base, would deflect the the blast, yeah the raptor might blow a small hole in the metal when the flame touches it in the last two to three seconds but it will take a second at least to cut through it and it hardly seems like it would excavate a crater.

>>11056064
ISRU propellant production on Mars will take several MW of power for every Starship

>>11056028
>OldSpace thinking
You sound like some "open your mind!" tinfoil. The Apollo lander was designed that way because it was the most practical solution. They did do extensive studies of a direct landing craft and found that an orbiter + small lander required much less delta-v. Sure you can refuel starship but that extra fuel then gets wasted on a direct landing instead of more payload.
>you need huge landers to establish a real colony
Most of that huge lander is just the lander itself, it's a waste.
>>11056031
By this logic landing a shuttle on the moon would make a good moon base.

>>11056057
That's a pointless waste of resources and money, Starship's highly flexible design could probably still be pushed to give it lunar landing capability with a sufficient safety margin. Either that or extremely large 100 ton reusable landers can be delivered to a staging point in LLO, supplies and propellant trucc starships will regularly cycle through that point, delivering palates of landing pad material to be shuttled down to the lunar surface. This larger task will be cheaper because expensive space vehicles will not be expended stupidly.

Begone from this place Shelby, and take your expendable vehicles with you.

>hurr durr Raptor will blast the surface too much

Did not seem so destructive during hopper flight at all. Granted, it was on a prepared surface and under Earth conditions, but it still seems to me this "problem" is way overblown.

>>11054821
Not even reusable.

>>11056079
Ok you are just ignoring every point and FUDposting. No more (you)s for you.

>>11055126
Itar wouldn't allow it.

The usaf should buy it. It can launch the x37

>>11056079
>Sure you can refuel starship but that extra fuel then gets wasted on a direct landing instead of more payload.

Wasted fuel is not very important as it is cheap and fungible. What you are saying may be relevant when the base is established and regular flights occur to the point when optimizing every tiny $$ is important. But not in foreseeable future.

>>11056082
I was just pointing out that if landing on the moon with starship is indeed a problem (which smells like fud to me) then you can use the "tried and tested american way to space" to prepare a landing site.

>>11056014
Send it to a warehouse on gateway.

>>11056096
Oh I wouldn't be averse to preparing a landing sight, I'm sure lunar dust will be a pain in the ass to work in and it will have to be cleaned out of vehicles as they make multiple lunar runs, it might even be a hazard in the long run if engines kick up big clouds of it that foul RCS packs or something like that. Just that the preparation of a landing sight could be done without expending equipment, I'm sure a 100 ton cargo lander could be made robust enough to reuse at least a few times so long as sufficient propellant is available.

>>11056084
Lunar regolith is actually very corrosive.
>>11056088
I'm done arguing with you, when is this moon landing scheduled to happen? I'll get the popcorn.

>>11056088
He didn’t ignore every point he addressed the whole argument, actually. Ironic how you guys will take the piss out of SLS all day but the minute any anons highlight one the the several legitimate flaws with starship, you cry foul, it’s “Fudposting”, it’s regarded, it’s oldspace, whatever.

Some guy said before that hoverslam is the “most efficient” method for lunar descent. Completely ignoring the fact that no “BFR” hardware has left the Earth’s surface, and also that the Apollo program has a strike rate of 100 with a CSM/two-stager-LM approach, which was deemed superior to the starship all-in-one craft. Getting lots of mass to the surface is a different story but Starship is not the optimal vehicle for that. People have been sold on the idea of a flawless, jack of all trades spacecraft. Well that is not going to materialise with Starship and that will be proven when whatever piece of shit Artemis lander Boeing builds for NASA touches down in a few years. Much fanboy ideology in this thread

^ Oi! That Anon with the collection!
| Put this one in!

>>11056057
>Or if it's possible to use lunar ISRU to make a pad
That's what I think, some kind of binder you could bring or even make on-site to glue the ground together.

>>11056115
it's not corrosive, it's abrasive
dumbass FUDposter

>>11056270
Apollo had one failure in flight. Luckily, everybody was recovered alive.

>>11056049
Raptor can throttle low enough that a mostly-empty Starship can not only hover, but actually accelerate down while firing during its landing burn on Earth. This means that at a minimum it can throttle down to accelerating at <9 m/s, which is a totally manageable rate of acceleration when it comes to hover-slam maneuvers. The Falcon 9 booster accelerates significantly faster than this.

Of course Starship landing on the Moon won't be fighting Earth gravity, so it won't be able to hover, but it will still be able to land just by doing a hoverslam. In local gravity it'd be pulling something like 5 g but in terms of m/s it'd only be accelerating at seven or eight meters per second per second. Easy to work with.

>>11056389
Yes. I was referring to the lem’s record , which stands at 6/6 for landing and ascent , and 7/7 if you include the job it did on 13 (or would have been able to do if the SM didn’t shit the bed), arguably its finest hour. The point is a three craft approach is ideal for initial exploration.

>>11056411
Forgot Apollo 9 and 10. 10 especially that was a nuts mission.

>>11054241
Why does it look like it is made from rusty iron?

>>11056426
It's recycled from suspiciously unused sewer pipes.

>>11056411
I disagree, the three craft approach was perfect for the heavily mass constrained and time constrained apollo program, which didn't have Starship available
significant effort to redundify and such the ECLSS will be necessary for the Mars trips anyway
Blue Moon is going to own the moon eventually, but right now Starship will be king

>>11056071
It even works without Lunar oxygen ISRU supply, Earth-based propellant only gets you ~100 tons to Moon surface and lunar oxygen gets you an additional 100+ tons for over 200 tons total useful payload mass. Even if you can't shuffle complex cargo like machinery into the cargo bay in Earth orbit (since Starship can't actually launch 200+ tons to LEO in reusable mode), you can always just include something like an empty ammonia tank and then launch 100 tons of ammonia on a different Starship to transfer across. Since ammonia contains nitrogen and hydrogen in an easy to store liquid form, it'd be quite useful to have on the Moon, where nitrogen is ultra-rare and hydrogen is tricky enough to get as well.

>>11055563
>It uses Methane as fuel which can’t be generated by ISRU on the Moon, unlike hydrogen.
Um, about that, how long will it take to get enough ISRU going to be usable? How long to find a site? How long to get the mining working? How long until you get a chiller and storage tank up there, especially hydrogen, which is a real bitch to chill?
My point is who gives a fuck about whether it can ISRU on the moon if we won't have any ISRU for multiple years later. This is starting to sound like another Helium-3 meme, only one that takes years instead of decades to be useful.

>>11056548
At least on the Moon chilling isn't going to be too hard, it's so fucking cold out of direct sunlight that all you'd need to do is shade your chilling unit and you'd do a lot of the work without having to spend electrical power.

>>11055994
He's catching shit for his terrible analogy and fallacy argument, not for "going against the company line". It isn't reasonable criticism, he has implied that it would be impossible for Starship to land on the moon.
>Using Starship as a lunar lander is like using an aircraft carrier for white water rafting.
>But you CAN’T use an aircraft carrier for white water rafting. It’s not just a matter of cost. It won’t fit in the river! If you tried to land Starship on the Moon its plume would dig itself into a crater, & destroy the base with its ejecta. It’d also be impossible to refuel it.

>>11054301
there isnt a government alive that will allow nuclear tech to used on a rocket which could blow up and spread nuclear waste for miles even with 0.00001% chance of it not happening.
nuke ships will only be used for cross planetary travel.

>>11056569
landing a Starship on the moon as a stunt is a good idea, kit it out with sensors to measure plume-regolith interactions and really advance the state of the art with some ground truth and put all that shit to rest
total cost: $200 million or so?
>>11056579
this isn't a super near-term thing, but a thorium reactor would be not only just mostly inert, but almost completely inert before activation

>>11056567
Chilling hydrogen is a pain in the ass because of the spin isomers. That still doesn't answer the question of how long it will take to A) find a site B) get equipment there C) get the equipment running D) make enough to refuel something E) ensure that the refueling equipment works on the moon? Yeah it would be great if you tried to refuel your only lander the first time and it didn't work.
We'll easily be on the moon a dozen times (and probably more) before ISRU is usable and working. Hopefully we won't have to wait on SLS launches for that.
Hydrogen vs methane is a dubious reason to ignore a lander vehicle. Especially if it turns out we'd just be doing oxygen ISRU anyhow.

>>11055319
>being sad because my parents were poor and I'd never have it
I know that feeling all too well.

>>11056579
More than 40 nuclear power systems have been launched into space, many of them are still orbiting over us right this second.

>>11056590
yeah landing starship as a stunt on the moon, especially before SLS(lets face it its will delayed to infinity) would certainly equate to NASA being immediately shelved or turned into the space equivalent of the DMV.

What im more pissed at is that more orbital housing companies like bigelow *sp.. arent putting their habitats into space to jumpstart the space tourism industries. I mean cant a couple billionaires front them the money

>>11056616
me thinks thats vastly different than the nuclear propulsive engine vs some rtg season to be used on satellites.

>>11056590
Thorium is radioactive and counts as nuclear contamination if spread (despite how retarded that is given thorium's 13 billion year half life), and thorium breeder reactors don't actually burn up thorium, they burn up a different and fissile isotope of uranium that thorium can absorb neutrons and turn into, hence the term 'breeding'.

Basically, thorium is not fissile, it cannot sustain a chain reaction. All a thorium reactor really does is fission Uranium 233, making a strong neutron flux. A surrounding blanket of thorium absorbs these neutrons and goes through a decay process turning it into uranium 233 after about a month. The U-233 is then loaded into the actual reactor.

>>11056621
Most all of them used low-enrichment uranium, but at least one of the new NTR designs being proposed to NASA also uses LEU, and there are other reactor designs that operate in that way as well, including the Kilopower system which only uses it's radioactive component to generate a thermal gradient. >>11056625 also makes a good point about thorium reactors, a lot of memes are circulated about it but one definite advantage is that you can start with thorium and in a highly neutron reflective shell slowly breed up enough U233 to initiate a fission reaction, this means you could launch nuclear fuel which is essentially inert from a radiation perspective and through clever reactor design allow it to naturally decay into a different fuel which actually generates your desired energy.

>>11056617
>would certainly equate to NASA being immediately shelved or turned into the space equivalent of the DMV.
no, anon
crashing an unmanned starship onto the surface of the moon as a test of plume-regolith interactions is not going to cancel NASA
cancelling NASA isn't even a good idea

I'm trying to find the erosion rate of an ablator inside a rocket engine. Unfortunately, pretty much every source I could find was more-or-less empirically derived. So I've decided to try to solve for erosion rate more analytically. Here's the basics of what I got so far. How does it look?

>>11056653
It looks like a lot of math I'd have to brush up on to fully understand, but I assume you do what one does to verify it, build a test system with known parameters, plug those into your equation and get your result, then fire the test system and see if the results match. If they do, you're right, if not then you have to go back and re-assess your math.

>>11056602
In fact with oxygen ISRU the same benefits that methalox vehicles enjoy are actually magnified for hydrolox vehicles because of the even greater disparity in mass between the hydrogen require and the oxygen required to get back to Earth. The Space Shuttle launch vehicle, despite running significantly hydrogen rich well beyond stoichiometric, still had over six times as much oxygen by mass than hydrogen (630 tons oxygen vs 106 tons hydrogen), meaning any hydrolox vehicle operating at the Moon could get 6/7ths the benefit of a full hydrogen-oxygen ISRU setup through oxygen-only ISRU, which only needs incredibly common metal oxides instead of much more rare water ice.

>>11056659
I don't have a way to test it yet, so I'm trying to develop the theory as much as I can.

>>11056700
Kudos to you, I think that's a good idea, I just don't see how one could tell if it was sound or not without creating a test to verify it.

Is he a fraud or not?

>>11056705
Maybe burning an acetylene torch on some test material (or down a cylinder of it) might work, but the hard part would be to be controlling the conditions that the material is feeling.

>>11056755
Yes, the Bigger Elon Hypothesis is fake. There's no Bigger Elon, Regular Elon, nor Elon Prime.

>>11056639
>including the Kilopower system which only uses it's radioactive component to generate a thermal gradient
Via sustained fission, lest we forget.

>>11056642
who said anything about crashing, im talking a controlled landing AND yes that would kill nasa, because people would ask what the fuck has nasa been doing all this time

>>11056755
is this a shoop?

>>11056667
You're still ignoring what it takes to make the shit in the first place, like using a magnifyig glass on an ant when there's a pit bull running at you. How long to build that shit, you don't automatically get just from being there.

>>11056879
A: you don't need ISRU to get 100 tons of payload t the Moon's surface via Starship, it just improves performance
B: while it requires a lot of energy, electrolysing metal oxides of iron and aluminum into metals and liberating oxygen is not a complex process, even if you're doing it on the Moon. It won't be set up instantly of course but I wouldn't put it farther than ten years farther out from the first Starship Moon landing.

>>11056857
yes, I'm the anon who shoop'd it

>>11056991
>you don't need ISRU to get 100 tons of payload t the Moon's surface via Starship
That's what I started this whole reply chain with, someone was trying to use that as a reason not to use starship, pay attention to the quote links.

>>11056756
Update. Got the thing simplified down to this (along with figuring out how much heat would be transferred from radiation and conduction). The only major problem is A_abl. I don't know how to deal with this especially since I want to use this equation at specific stations at an engine which are treated to be infinitely thin (such as the nozzle throat and exit) and thus don't have an A_abl. Anyone got any ideas?

I wish we had someone like musk in charge of sabre/skylon.

>>11057059
It's a britbong projects, it would be fucked even if someone more impatient and ambitious were in charge of it, on top of that SSTO spaceplanes are big gay and not worth the enormous investment necessary to make them work. Much better to use a lifting body second stage in a normal vertical stack rocket.

>>11057033
>pay attention to the quote links
no

Cancel SLS. Begin Private EM-1 development. NOW.

>>11054558
>Also if you suppose the tictac stories actually checked out, there are other problems with how you could even move and accelerate anything that fast in atmosphere. Also you can't see a fusion propulsion system on it.
Although this story is a fairy tale, it's theoretically possible to accelerate an object and make it do crazy maneuvers in an atmosphere with a Magnetohydrodynamic drive, you just have feed it enough power with something like a miniaturized fusion reactor for example.

>>11057159
Presuming of course you can build a mounting which will allow the drive to impart that maneuver to the rest of the vehicle without tearing itself clean out of the vehicle, and presuming the rest of the vehicle's structure is robust enough to not be instantly transformed into shrapnel by that same stress.

>>11055329
Orion *cough* SLS before it was called SLS *cough* was supposed to use an actual rollercoaster as a launch escape system.

>>11057152
W-What was LISA and Jupiter?

>>11057159
Fusion is 10x less power dense than fission, end this meme retard

>>11057210
>LISA
https://en.wikipedia.org/wiki/Laser_Interferometer_Space_Antenna

>Jupiter
https://en.wikipedia.org/wiki/Jupiter_(rocket_family)

Just my guess, though.

Put some pictures of Starship Mk1 through content aware scaling to make it even more crinkly. What do yall think?

>>11057221
>CHODE

>>11057210
Jupiter was the original rocket family design for SLS designed simply to replace the shuttle at first using previously used parts then be slowly upgraded to return to the moon but some suit decided that they wanted to eat all of the cake at once so SLS was conceived and the Jupiter family was tossed into the bin.

LISA is the Laser Interferometer Space Antenna that NASA was building with the ESA until ((budget constraints)) forced them to drop the funding and the ESA have been desperately trying to cover the shortfall. They recon it will now take 15 years to develop without NASA.

>>11057222

>>11057225
>take 15 years to develop
>anything
>ever
interesting to see that the ESA is just as much a corrupt mess as NASA is
getting rid of the death penalty was a mistake

>>11057064
SSTO with Sabre could be very viable actually. Shame they are using LH2 meme fuel and not based Methane. They are also oldspace tier at developing it.

>>11057222
UH THIC

>>11057235
>Skylon
>37 years in development
>no hardware of anything
This is beyond oldspace. At least oldspace would've made something tangible to show off. This is more like oldspace 2.

>>11057245
>Development hell boogaloo

>>11057245
They got their fancy heat-exchanger at least...

>>11054515
laser fusion was always a meme-even if the NIF has worked (and even 7 years after its initial failure its still way off) turning that monstrous assembly of lasers into an economical power plant is virtually impossible.

I keep an eye on the next gen tokamaks and some of the FRC designs getting messed with. ITER is interesting, but if THAT is what fusion power has to look like to work, it's hardly worth pursuing.

>>11057262
It's an amazing piece of engineering I have to say.

>>11055153
Muon beam inflection - Gage interaction propulsion
Small semi-stable fuel source - Isotope of element 116, mistaken for 115 by Bob Lazar

Muon beam straight down from a cone.
Second muon beam 90 degrees off from that one, near the end of the cone.

The beams intersect perpendicular near the cone opening.

Precision adjustments in the 90 degree off-set beam, change the propulsion properties, via quantum Gage interactions. The vectors of individual tensor moments in space-time can be flip flopped with relative ease, utilizing this design.

The interaction with atmosphere can be limited with a dampener unit that acts on the same principle, a second assembly outside of the main propulsion assembly, where the vector flip flops are only used to dampen the Gage quantum effects from the first engine.

But what the hell do I know? I'm just a random guy that got abducted, told all of these technical scientific secrets in a room with Michio Kaku and Dr. Steven Greer, by a being that needed assistance fixing it's craft, and I was allowed to keep some of the memories.

(Just because a being can operate one of these things, doesn't mean that it can make extensive technical repairs on it's own! :D Brought in some outside help.)

Of course there was the typical "Nanananana na no one's gonna believe you!"

But I really didn't care, and neither did Kaku. Kaku was just stoked he got to watch all of their technical scientific discoveries and learn how a bunch of big universe stuff worked. He didn't give a single fk about the memwipe.
Dr. Greer went up in arms over the memwipe, was pissed he wouldn't be allowed to tell people. He got pissed at me, that I was going to be allowed to keep memories, and I was refusing to disclose or snitch on our little buddy in an official capacity. Greer was subsequently booted from the event.
Kaku and I got to stay, Kaku got his memwipe. I got to keep some memories, and the secret is safe as it can be, because I'm a Nobody.

>>11057399
You get a few minutes to screencap my post, if you want. Then I'm ripping it down, before someone that knows a little bit about whether my claims are true or false actually sees it.

>>11057034
pvdf film probe, at your "infinite thin" zone
As far as testing goes ^ This would allow you to get some real fine, real time data.

Do you account for vibratory variance and radiative interference sources?
You better do your test in a clean room, with a faraday cage.

(Depending on your precision)

>>11057407
You are dumb. I am not whoever you were talking to before, I just wanted you to know how dumb you are.

>>/sci/thread/S11054241#p11057399

>>11057407
Oh look, archives. I'm making a mistake replying to you, because you're just doing this for attention, but eh.

>>11057225
>Common tanking
The biggest lie ever told.

>>11057235
They are looking at methane: https://forum.nasaspaceflight.com/index.php?topic=40846.900

>>11057245
You're talking like there's been a team on it for 37 years, whereas the truth is there's been years with barely any funding and just a few people keeping the idea alive. Current rate of development and actual working hardware on the stand suggests it's a bit premature to mock. And I'm guessing if it were American you'd be all > 'woo yeah go USA muh ingenuity!!!1!11! '

>>11058096
Don't flatter yourself britbong, I don't pick on Skylon any more or less than on the Shuttle or SLS for using the RS-25, another hydromeme engine which is simultaneously ingenious and also dramatically overpriced, overhyped, and underperforming. Skymeme isn't a flawed idea because of it's country of origin, it's flawed because SSTO spaceplanes are a sub-optimal design without mass drivers or skyhooks.

>>11058138
I say again: they are looking at methane so the hydromeme jibe is somewhat premature, and apart from that SSTO isn't the only application of the tech that's of potential interest in this forum. Hypersonic transport and a high altitude / high speed mothership a la stratolaunch spring to mind. I don't think this tech is disappearing any time soon, but granted Skylon was always a bit of a PR meme and SSTO a very big reach.

>>11058138
I might add there's plenty to mock about Britain's almost complete refusal to even attempt to compete in space (along with pretty much everything else) but the sabre tech isn't really reasonable to include in that list.

>>11058096
>Let's start with Methane: Yes, RE are actively looking at how performance would be changed by a switch to Methane, as well as confirming that it would simplify structure (prop density) and greatly simplify ground handling and safety particularly for manned flight and spaceflight. This also came with confirmation that while SSTO remains the 'holy grail' goal, RE are taking a much more pragmatic approach to development with TSTO being more viable.

Interesting. Skylon as a methane TSTO may actually work.

>>11058389
isn't it easier to make a methane SSTO than a hydrogen SSTO?

>>11058389
I wonder though, once the first stage booster is expended what would be the point of an air-breathing second stage when the vehicle will have already been yoten nearly out of the atmosphere by the booster by that point? I'm imagining a reusable methane breathing TSTO, it's ideal configuration being a vertical stack, and some form is materializing in my mind...it's got aerodynamic surfaces to give it some extra lift during atmospheric travel and to aid in returning to Earth at lower temperatures to improve it's safety and lifespan...oh that's right, I know where I've seen that before!

>>11058405
Not really. The required mass fraction would be pretty high for a methalox SSTO compared to a hydrolox SSTO.

>>11058405
20-30% greater weight of propellant, 40+% smaller fuel component tanks with no need for insulation. The overall payload can be slightly increased in mass and significantly increased in volume. Significant reduction of turbomachinery mass and complexity in the engines which is kinda hard to quantify without a complete engine to go off of.

>>11057059
They don't need Musk, they just need the kind of money Musk poored into SpaceX to get Falcon 1 into LEO.
It's the old story of no one believes you can until you do with the only difference being Skylon isn't owned by a billionare.

>>11057204
is that a roller coaster?

>>11058464
Even astronauts need to have a bit of fun.

>>11057451
>>11057449
>>11057407
wow, that's . . . stupid.

>>11058411
That's the thing, a much better mass fraction is actually a lot easier to get with methane than with hydrogen, because liquid methane is about 5x as dense as liquid hydrogen. Conversely if we could get a 90% propellant mass fraction out of a hydrolox rocket, that's definitely enough to do SSTO even with conventional rocket engines and nozzles (no aerospike meme or air breathing boost phase etc). The problem becomes, how the fuck do you do all the structure AND landing gear AND TPS coating etc and still get a useful payload, or even achieve orbit at all? Doesn't help either that hydrogen fueled rockets have lower TWR inherently because they need larger pumps to move around lower density propellant,. meaning there's always going to be a disadvantage in terms of engine thrust and/or weight when compared to a similar methalox engine. Just compare the size of Raptor and the SSME for an example of what I mean, and note how much smaller Raptor is despite getting about the same thrust (less in vacuum, more at sea level, future Raptor engines will be more powerful than SSME across all pressure ranges).

>>11058464
For escape.

>>11058529
Escaping boredom?

>>11058522
>Just compare the size of Raptor and the SSME for an example of what I mean, and note how much smaller Raptor is despite getting about the same thrust (less in vacuum, more at sea level, future Raptor engines will be more powerful than SSME across all pressure ranges).

That’s not true at all, the reason the RS-25 is so big is because it has an altitude compensating nozzle, which allows it to achieve a good specific impulse at sea-level (ISP:366), all the way to vacuum (ISP:452).

>>11058547
It's not so much altitude compensating as it is that is has a nozzle that's just small enough to be stable at sea level but larger than typical so it's more efficient in a vacuum.

>>11058522
>Raptor engines will be more powerful than SSME across all pressure ranges

I highly doubt this considering RS-25s have been ran at 113% thrust to produce 2360KN of thrust, whilst Raptor is struggling to go past 1800KN at 250 bar.

>>11058567
*at sea-level

>>11058547
Dude, look at the size of the power pack. It's huge compared to Raptor. I agree that the nozzle is not indicative of actual engine size, because the power pack is the actual engine.

>>11058567
is 2360 kN sea level or vacuum?

>>11058567
RS-25 generates 1887.1 kN of thrust at sea level at 113% throttle. You're confusing sea level thrust for RS-25 in vacuum for sea level performance. 100% throttle RS-25 "only" produces 1670 kN at sea level. It's in vacuum at 113% that they get 2361.7 kN.
SpaceX eventually wants to get Sea level Raptor up to around 2500 kN of thrust, which I think they'll achieve since they're going to be keeping up this process of continuous development and improvement as they go. I don't know if that figure is for operating in vacuum or for sea level, but I do know that it is a performance metric of the sea level variant. The vacuum engine operating in vacuum would definitely be more powerful than RS-25, even with the current Raptor power pack.

/g/ is making me mad with starlink fuddery

>>11058609
see >>11058632
It's vacuum performance. Also, due to the large disparity in vacuum vs sea level Isp, there is also a large decrease in thrust at sea level proportional to the vacuum performance of the RS-25 engine

>>11058635
The problem is lots of retards think it'll be high bandwidth, it won't.
It'll be low bandwidth low ping which is better than nothing for the 3rd world and good enough for high speed traders.

>>11055799
Methalox RCS is absolutely going to evolve into a secondary set of smaller OMS-style methalox engines on the lunar Starships, mark my words.

>>11058637
3rd world, HSTs, lots of the low-pop-density parts of North America, and also great for boats and planes and trains and whatnot

>>11058653
>lots of the low-pop-density parts of North America
This. It'll be nice to not randomly lose internet for the whole day because McFarmer's electric fence found a new connection to the buried telephone/internet cable.

>>11058652
why

>>11058635
What I don't get is how some are shitting on the discussion because they think Elon Musk is a Reddit thing. IIRC Elon isn't active there.

>>11058665
https://www.youtube.com/watch?v=OIRZebE8O84

>>11058682
I have been listening to his audiobooks on youtube, he's one of the good one that puts a lot of though into his ideas.

>>11058589
for some reason I was naively assuming that the hydrogen meme's low density would cause the thrust density to also be low, but is that true? low prop density is going to impact your engine T/W due to the size of the required pumps, but will it impact the size of your nozzle? On second thought, I don't think so.
RS-25 has a thrust density of 454 kN/m[math]^2[/math]
Raptor has a thrust density of ~780 kN/m[math]^2[/math]

Why aren't there more jet based VTOL aircraft? Are they just that difficult? I'm talking more helicopter-like airframes in terms of function and workload, not so much hovering jets like the harrier.

>>11058740
>Why aren't there more jet based VTOL aircraft?
Because jet engines need fresh air to operate well. Air that has contaminants in it and reduced oxygen (such as the exhaust from a jet engine) will cause the jet engine to reduce in power upon ingesting it. For a jet VTOL, it'll very quickly be surrounded by this less useful air during take off and landing due to it blasting its exhaust into the ground (which it is very close to). So any VTOL jet will be very vulnerable to engine stalls during take off and landing (which are the parts of a flight that are most accident prone) as more of the air around it gets filled with its own exhaust. There are some work arounds to this but are limited solutions.

>>11058757
neat, thanks. do you know any places I could read more about this? I've been googling dumb phrases trying to learn more about it.

>>11058740
VTOL nut here, disc loading.

>>11058764
I don't know any singular source that has everything about jet VTOLs but the Avrocar is a perfect example of how not to do a jet VTOL so that might be a good read.

/sci/ needs to do a screening of this:

https://www.youtube.com/watch?v=aS-9dYFb_9A

>>11058632
>>11058636
The RS-25 produces 1,860 kN of thrust at sea level though, slightly more than Raptor does currently.

>>11058809
>That strap on booster staging.
M U H

It should be noted that the RS-25 is easily double the size of a Raptor, with a substantially larger combustion chamber and an expansion bell almost large enough to fit an entire Raptor inside of.

>>11058828
I'm still amazed that those boosters could be done like that back then. I would've been very nervous about the idea of having partially attached boosters which still have their engines firing, especially if I had to work with analog computers for the GNC and staging.

>>11058857
So you're saying it's not about size but how you use it?

>>11058809
Damn, this looks pretty good.

>>11058868
no it's about propellant density
common tank subcooled propane and LOx, with one of them in a bladder

>>11058868
Ah enginelets, when will they learn...

https://m.youtube.com/watch?v=5cnC5j95axw

>>11058885
This is my favorite one.
https://youtu.be/6YTaG91KD5s

>>11058868
Yes, and about what you put through your engine. Raptor burns Metha/LOX, a much denser propellant mix while the RS-25 burns Hydro/LOX, if they were the same size and operated at the same pressure the Raptor would greatly outstrip the RS-25. Or say if you made a Raptor-like engine the same size as the RS-25 it would put out much greater thrust. The same goes for tankage and plumbing, Metha/LOX is 20+% less efficient in terms of Isp compared to Hydro/LOX, but it's tanks on average require 40-ish% less volume, they're much closer to the size ratio of Kero/LOX tanks. It's why I'm always so critical of hydromeme engines and rockets in all of these threads, hydrogen is only the most ideal propellant on paper and too many space agencies and projects become fixated with those big paper numbers. This is especially true for sea level stages, your hydrogen tanks are bigly yuge and you'll have to drag those things most of the way up with you, Saturn and N-1 had the right idea, your booster stage doesn't need to be efficient, it needs to be compact with high TWR to yeet the payload as quickly as possible past the densest parts of the atmosphere. Once you're up you can start thinking about more efficient second stages, where efficiency can actually be useful to you.

>>11058900
>"It's why I'm always so critical of hydromeme engines..."
>tfw your favorite rocket engine is the J-2

>>11058906
>tfw
>no face

>>11058930
>tfw
>no feel

>>11058930
tfw is "that feel when", not the same as mfw "my face when"

this has been old memes with anon brought to you by xbox hueg

>>11058906
damn thanks anon

bump kek

>>11059155
you dont need to bump on/sci/ especially in /sfg/, it's a slower board during the day.

>>11059161
it takes what, 24 hours for a thread to fall off of /sci/?

Elon on Raptor

https://twitter.com/elonmusk/status/1183813898748563456

>>11058809
Made on $6M USD(400M Ruble) budget. The power of PPP makes this equivalent to $20M USD. Sounds about right.

https://twitter.com/virgingalactic/status/1183819914823503872

New launch animation as of an hour ago. Same one from the presentation, but at a better bitrate.
https://youtu.be/C8JyvzU0CXU

>>11059192
This week will truly be something else for space/flight suit enthusiasts.

>>11059208
they partnered with fucking Under Armor, goddamn what the fuck
I want to see all these IVA/launch/landing suits on a catwalk

>>11059192
When will Roscosmos team up with Adidas? Will we see some of those stripes on the suits?

>>11059218
>Federation is confirmed to have a massive fucking subwoofer that can shake the entire ISS with hardbass

>>11059228
Would loud music sound more intense on a spacecraft/spacestation since there's no atmosphere for the sound waves to escape to so they just bounce around inside the craft/station?

>>11059240
everything would probably resonate for longer

>>11058823
slightly, and currently.

What happened to this MIT tensile spacesuit? There hasn't been an update on it for fucking years.

>>11059240
What about a pulsed laser that through thermal shock vibrates other stations walls to play hardbass.

*flys*

>>11058671
Because Raptors are absolute overkill for landing on the moon.

>>11059192
>>11059208
>>11059211
>the advent of spaceleisure attire that will dominate urban fashion in the mid-2020s
>>11059218
>>11059228
S P A C E | G O P N I K

>>11059869
unless you're landing with a 600 ton vehicle.
Hover-slams are reliable, we don't need a tiny engine to land at cm/s.

>>11059887
Someone also raised that the methalox thrusters might have just barely enough thrust to deal with cutting the Raptors a little higher off the surface than you might otherwise.

>>11059887
For lunar payloads, fitting a pair of Merlin-class methalox engines for descent thrust represents a negligible weight penalty for the great improvement in descent/landing reliability that they offer.

They're absolutely not needed for earth-orbital and Martian-use Starships, but I can very easily see there being a lunar Starship variant with a slightly different landing leg and engine configuration optimized for lunar operations.

>>11059375
i dont know but we need to get into the skinsuit era of space travel ASAP

>>11059911
Consider the economic side of things, and realize that developing an entire additional engine purely for Moon landings is the cost here, not the added weight per vehicle.

>>11059876
Кocмичecкий Гoпник!

>>11059895
Maybe a virtual hoverslam some distance above the surface with the rest handled by thrusters

>>11056082
>Begone from this place Shelby, and take your expendable vehicles with you.

Doesn't work that way... he won't "begone" until he loses an election.

Remember that next time he runs, toss a few bucks to his opponent.

>>11056755
Depends on context.

Tesla is a long con on the government.

Boring Company is pretty obviously a joke his fanbois took seriously.

SpaceX seems, so far, a lot more legit.

>>11057195
>>11057159
what it would do to the atmosphere would be pretty fucking noticeable.

>>11059003

>>11059211
>>11059218

>>11060066
>energizer logo
>on the booster that burns out a minute and a half into flight

>>11059951

>>11059375
They've made some progress by including a titanium alloy wire corset that encloses the wearers torso, by passing a low electric charge through this wire it will contract where some as-yet undesigned mechanism will then lock it in place to compress the chest sufficiently. This also has the benefit of acting like a heating element, so the suit can quickly be brought to a comfortable temperature. Elastic as it turned out wasn't sufficient to provide pressure in all the right places, they needed something which could contract in a different way, thus the titanium alloy.

>>11058464
yes. It is a rollercoaster, did you not read my post?
>>11058530
Escaping a fiery inferno of death. For Orion a rollercoaster was necessary to get the hell away fast enough.

>>11060066
it actually looks good.

>>11060066
>imagine the PR hit if that was Challenger or Columbia

>>11055452
we're fucking doing it

probably taking the aerosurfaces off of the lunar version

gonna need like six, maybe eight tanker flights, but this is the kind of mission we're going for here

>>11055563
jesus nobody here ever thought of any of that! oh my god thank you so much, this is just like that time somebody in this thread reminded us to put toilets into the starship design!

>>11059003
for great justice

>>11060248
>we're
>us
hi musk

>>11060248
>this is just like that time somebody in this thread reminded us to put toilets into the starship design
t-thunderf00t?...

>>11055294
lol thanks for the chuckle

>>11060369
no just some peon in hawthorne

and I know I'm not the only one in this thread either

>>11060551

>>11060248
So if you're taking aero off is it expendable, or reusable from Gateway, or what?

>>11060551
What are you doing about the landing site issue? Mars might be ok but the moon is just fat stacked layers of regolith.

I wonder what Shotwell smells like

>>11060630
Methane and oxygen braps

>>11060630
Elon Musk's semen.

>>11059961
*laughs in orion*

>>11060882
Helps when the government bankrolls everything down to your executives luxury yacht.

>>11059951
asuka spaceshuit when

>>11059375
How does the tensile thing work around your nuts? You just put up with your balls being squashed or what?

>>11059375
>>11059951
>>11060076
>>11060963
>>11060970
Skintight cucks begone...

>>11061014
xEMUchads rise up!

>>11061014
SpaceX isn't a proper suit, but it does look pretty good, nowhere near as good as skintight but still a bajillion times better than this NASA trash

>>11061016

>>11061014
hello, yes, I have bad taste, how could you tell?

>>11061042
>>11061052

I’m sorry that I prefer the functionality of being able to operate in a vacuum and on the surface of another body, over being able to look like an extra from a campy science fiction B-movie.

>>11060071
>they want to take this from you

>>11060248
>probably taking the aerosurfaces off of the lunar version
They need to get it back, anon. That means aerobraking at Earth.

>>11061109
you don't like this?

>>11061133
>that face
Christ-

>>11061133
Sure, in the future. But current skintight suits seriously limit movement (e.g. SpaceX’s DM-2 astronauts take off their gloves and roll up their sleeves to get better movement) so big and baggy is the only viable choice for an astronaut who actually wants to get shit done.

>>11061125
specialized lunar starship could make sense if they use lunar orbit rendezvous, with a modified ship going between LLO and lunar surface repeatedly

>dabs on you
Or rather, attempts to dab.

>>11060332
>xbox hueg colony drop

>>11061202
The Boeing suits are actually more flexible than the SpaceX ones apparently. However, the life-support connection being on the chest looks intrusive.

>>11060951
Assuming that engines cost about 60% of development as they do account for 60% of a launcher's cost, then Merlin cost about 180 million to develop. It's not *that* much assuming SpaceX continues to profit well from their already existing launching business.

>>11060600
the biggest issue I can see with using a Starship to deliver cargo to the moon and then attempting to recover it is, where the fuck are you going to put the cargo that it won't get blasted by launch?
I think expendable is better at least until there is ground truth on large landers
>>11060970
I would imagine a balloon cup?

>>11061249
Behind deflection panels. Make sure the end of the panels closest to the rocket are buried in the regolith, and angle them up and away.

>>11060970
The suit only needs to squeeze you at 1 bar of pressure, it wouldn't squash you any more than the atmosphere normally does, probably even less for most parts of your body, maybe half a bar.

>>11061259
if you're breathing pure oxygen in your bubble helmet you can get away with like... 5 psi or something ridiculously low like that? I don't know what pressure or what mix of nitrox you need to eliminate pre-breathe considerations going from 78-22 at 18 psi
I wonder what the international/interplanetary breathing air standard will become?

>>11061255
oh, that's a good idea

>>11061332
new
early because you idiots can't be trusted to make an op