/sci/ - Science & Math

You'd think that if there was going to be one group of people who know how to make things happen it would be billionaires, but that doesn't seem to be the case. It seems like most billionaires who are interested in doing something useful with their money end up spending it to treat the symptoms of a primitive civilization rather than to move things forward. The ones that do have intelligent ideas generally do not have the competence to actually make things happen. Musk seems like he might be an exception to that, but I'll be impressed in ten years when he and all of his companies haven't gone bankrupt. I will give him credit for doing almost exactly what I would do if I were a billionaire. Spaceships, electric cars, and renewable energy. The Model S would have been better if I had designed it, though...

Oh, it's not just plans, either. They've got a full-sized first stage of a rocket hovering and landing itself safely:
http://spacex.com/multimedia/videos.php?id=0

Musk said he's hoping to have this thing do a supersonic test flight before the end of the year.

no1curr

Elon Musk giving a tour of SpaceX:

https://www.youtube.com/watch?v=TQ6tZtGrShg

This is also pretty cool:

https://www.youtube.com/watch?v=c1HZIQliuoA&feature=player_detailpage#t=375s

video looks amazing. i have no idea how to estimate when these things will be general use because I am in no way very knowledgable about the topic.

>multiple flights per day
holy shit that would be the most amazing thing

how can they land this big ass 1st stage thing safely on earth? this looks impossible.

>Flyback first stage
>Exoatmospheric turnaround
>2STO rocket
I really hope they rethink this. That, or only use it for the Falcon Heavy's boosters and nothing else.

>>5287831
>how can they land this big ass blimp thing safely on earth? this looks impossible.
No, but seriously, the landing is the more sane part of this proposal.

>>5287852
Well, they don't show the whole flight sequence. I don't imagine they'd actually fly down ass-end forward with the rockets burning the whole way.

They probably bring it to a reasonable speed roughly over the landing zone, then nosedive it until air resistance has them subsonic again, and turn around again with the maneuvering rockets to land.

>>5287902
Come to think of it, the landing gear might double as air brakes / control surfaces.

i wish space exploration can happen in my life time

Musk is the hero we have all been waiting for.

I hope I live long enough to see the day when I can afford to go into space. I wouldn't even mind dying upon descent.

I hope this leads to some more investment in space exploration:
http://science.time.com/2012/11/20/a-mars-announcement-for-the-history-books/

This would be cool:
http://www.space.com/17856-nasa-deep-space-station-moon-farside.html

I hope we build gigantic space stations soon, or a spaceport on the moon. Even though it would be incredibly expensive, we could have the benefit of easier launches. Maybe Planetary Resources will get the materials we need so we can start building bigger things in space.

Imagine going on a vacation, making a pit stop at the nearest space station, drinking space beer at the space bar, playing around in microgravity, watching the dozens of spacefaring vessels come and go from the docking bay. After a day, you go to the moon to spend a week driving a dune buggy in the craters, drinking moon beer at the moon bar, and visiting historical sites.

You take another small trip to the L2 space station, observing distant systems through Brobdingnagian telescopes with uninterrupted views of the universe. While you're there, you visit your son who is studying abroad, completing his specialized physics courses at the solar system's premiere astrophysics university.

You're sad to leave, but you remind yourself that the Mars commercial resort will be done in five years, and you'll finally be able to observe those bacteria you've been hearing about.

Oh, to live 700 years in the future . . .

>>5288045
Like Musk says, the launch prices could go down to $10/lb with this kind of system. A $10,000 space ticket isn't beyond imagining.

If it costs $10,000 to take a person up, you can send 100 people up for a million. That's a serious work crew, and all kinds of companies would be building orbital facilities. With equipment going up at $2000/ton, people would be starting space businesses on their credit cards.

Moon mining would quickly become a thing. Before long, you might see all of the re-entry craft produced from lunar materials, further reducing round-trip ticket prices. Rocket fuel, structural material, and all sorts of raw materials can be had from the moon, and launched for much lower prices than from Earth.

Orbital manufacturing and space solar power could become major parts of our economy.

>>5289089
>$2000/ton
Sorry, that should have read "$20,000/ton".

Anybody remember the last few times Humanity has gained new access to a previous restricted resource?

All the gold rushes in history wont compare to the investments going into space for the vastness of the minerals there

>>5289209
Even aside from the minerals, think of the energy. In space, you can make the concentrator for a solar power collector out of atom-thick foil. There's no wind to blow it over or tear it, and no force of gravity to pull it down. There isn't even oxygen to corrode the surface. You're not even attached to anything that turns away from the sun all the time.

You could build a gigawatt power station from perhaps a ton of materials, and it would generate at full capacity 24 hours a day, with only occasional eclipses.

>>5289209
Speaking of gold rushes, the latest model of heavy metal accumulation in the Earth's crust is that it's a product of meteor bombardment. The oceanic crust has been driven under and remelted since then, so it's depleted of heavy metals, but the continental plates have kept bobbing along the surface and retained its meteor deposits.

The moon has probably got about a third as much gold and other heavy metals as the Earth had before we started mining. On top of that, it's easier to dig in because of the lower gravity, and plentiful solar energy is available to power mining equipment and refineries.

The gold rush might be a very literal one.

>>5289293
Yes but there are tiny particles of dust and debris flying around faster than bullets.
Good luck with your atom thick panels.

>>5290094
You wouldn't build something like that in LEO. There's be too much exospheric drag for such a large object.

But occasional impacts wouldn't matter. They'd just poke tiny holes in the foil. Maybe every ten years or so, you'd have to make a new reflector. Or you could have a little machine recycling it bit by bit. Even if you spend a megawatt on maintenance all the time, it's insignificant.

http://www.bbc.co.uk/news/science-environment-20389148

>Elon: I'm hopeful we will send our first person to Mars in the 10-15 year time frame
>BBC: As soon as that?
>Elon: Yes, we can't wait too long. I don't want to be so old that I can't go.

FUCK YEAH

>>5287821
oooooooooh

Elon is a legend. I sincerely hope he is an absolute runaway success.

The more successful he gets, the more fun shit he will do.

>>5290064
you are very intelligent.
you have blown my mind sir, this space mining things has interested me, do you have any source?

For anyone wondering how they'd do it. They plan to launch from Texas and land in Florida

>>5291365
http://en.wikipedia.org/wiki/Planetary_Resources

>>5291373
>http://en.wikipedia.org/wiki/Planetary_Resources
thankyou anon

>>5291373
I thought the moon was primarily crustal from Earth material from the large impact which created it and that most of the heavy elements were left in the core of both worlds which fused into 1. I would think going to the moon for resources heavier than iron would be a bit wasteful as opposed to asteroid mining which has the same composition as the early solar system but retains the higher percentages of heavy metals because they had no planetary core to fall into.

yes?

>>5291411
There are no plate movements on the moon. Which means that all heavier elements deposited on the moon via meteor impacts since the formation and solidification of the moon are still on the lunar surface which should give it a better ratio than the earth, though perhaps not comparable to some pristine asteroids.

>>5289089
The nice thing about our corporate run society is that when ever something meaningful that benefits them comes about, they can use it.
If they really wanted and thought it was liable, we could very easily see geo-stationary space elevators in the near future

>>5291474
Things have to be cost effective, a space elevator is not such a thing, theres more problems with the concept than any sufficiently valuable gains. Rockets will dominate until something better comes along. If SpaceX can do what they set out to do, we will see a very large economic boom even before actual mining and energy production becomes a possibility. people will want to take space for themselves, so they will research. Research is one of the most expensive things that mankind ever did. Very resource, energy and manhour intensive. And im all for it. We need something to drive us, like during the cold war and its space race. The apathetic ways people live and go crazy for iphones is riddiculous, its as if we entered a new dark age since the cold war. Most research goes into developments for the media industry.

im more excited about skylon getting funding

http://nextbigfuture.com/2012/11/european-space-agency-gets-10-billion.html

>>5291563
It's just that most people find their navel more interesting than something outside it.

>>5291563
Even if the capital cost of building a space elevator is ignored, most plans for one are based on microwave power transmission, which would actually make them less energy efficient than a rocket launch.

It's a neat idea, and a fun theoretical application of material science, but compared to rockets, it's like an idea of replacing commercial airline routes with sky bridges held up by helium balloons.

>>5291569
The Skylon is a neat idea, but SpaceX would beat their $/lb program goal with just the Falcon Heavy with reusable boosters, which is based on working technology and seems feasible within two years.

The absolute earliest Skylon flight would be in 2018. By that time SpaceX's reusable rocket program could be mature and beating the Skylon cost effectiveness goals several times over. With lower capital costs per vehicle, it could also be expanded much faster, supporting a very high volume of traffic.

The SpaceX program might fail, and Skylon might succeed, but SpaceX by far is the more immediate prospect.

Serious question: How does Space X differ from Boeing and LockHeed Martin and their relationship with NASA?

Everybody keeps talking about the privatization of space flight and how Space X will revolutionize everything but politically and economically they seem to be in the same relationship that Boeing and LH. Martin already had with NASA, i.e. they big and win contracts. So what's so different about Space X?

Elon Musk would be the primary difference between SpaceX and any other corporations or competing contracts.

The man is a god damn genius, with a huge vision. True Humanist. I myself am very excited about both SpaceX and Tesla Motors (Musk's electric car company).

In combination with Planetary Resources, the exploitation of space is Humanity's best hope for survival and that is certain. Once we harness the resources of our Solar system we can kiss all the petty squabbling on Earth goodbye...that is as long as Religion finally gets put in its place.

>>5289293
> There's no wind to blow it over or tear it
Of course there is, do you know nothing of space? Guess where high-energy particle events in the atmosphere come from. Guess what the momentum of light is. Space may be really empty compared to earth but there is plenty of shit flying around up there, and it is going pretty fucking fast.

>>5292078
Nothing. It's more fake privatization, like defense spending. Companies are made from whole-cloth so that "the market" can "work." But there wasn't a market for space travel. Therefore the price mechanism cannot allocate resources any better than the government just because we've effectively sold NASA to some rich fucks.

>>5292113
>But there wasn't a market for space travel

>>5292158
There wasn't. What is there to dispute?

>>5289089
oh, there's nothing on the moon of any value
We need to go further out for actual bulk minerals which will take a bit longer

>>5287717

Excited? I've been fapping all day!

>2030
>Moving on holiday to Mars moon Deimos
>I sit down with other 10 people in skylon on spaceport
>Not even two hours later, we are in LEO, enjoying low gravity and docking with SpacePort3
>We have some low gravity food fun, then we move to spaceship that will take us to Planetary Resources refuel station halfway to Mars
>after two weeks we are doing flyby next to Planetary Resources heavy transport ship with size of Twin towers
>Land on hollowed out asteroid base for refueling
>Enjoy vacation with view on Mars and head home

where is Elon from?
I can't place his accent

>>5292331
nevermind, just watched the second video posted
He's from South Africa

>>5292207
>nothing on the moon
>regolith
>moonkrete
>helium 3
>water
>potentially iron
The moon is chock full of interesting goodies.

>>5290571
>based elon

>>5292207
>there's nothing on the moon of any value
There's plenty of whatever you find on asteroids, because asteroids have been falling on the moon for billions of years, and there's no weather to spread the materials around. That's why it's covered in craters. Some of those craters undoubtedly contain tons of gold.

The moon's close to hand. It has enough gravity to be convenient, not enough to be inconvenient. Lots of sunlight, no weather, relatively good stability. The common soil can be processed into rocket fuel, fuel tanks, rocket nozzles, and heat shields of sufficient quality for launching stuff from the moon, for orbital maneuvers, and for Earth re-entry.

Once we get reasonably good LEO launch capabilities, the moon is the natural place to start working.

>>5292377
Oh, I hadn't thought about the addition of asteroid mass
I was just thinking about how the moon is primarily composed of shallow earth metals

>>5292110
>build giant atom-thick solar panel
>accidentally a solar sail

>>5292399
Well yeah, but earth materials are worth more if they're already in orbit. It costs a lot of money to bring stuff up and if we can have stuff that's much easier to access, that's all the better.

>>5292405
and that includes water. The potential for large amounts of water in space means that effective fuel can be produced off of our planet

>>5292402
You do have to account for the solar sail effect, of course, but it's not that big of a deal, especially when you're in orbit and have a gigawatt of electricity handy.

You might need some small shipments of reaction mass from time to time (and I imagine most of these power plants would be attached to factories of some kind, so they'd be getting regular shipments), but mostly you'd be able to cancel it out by playing with the angle of thrust as you orbit.

Speaking of solar wind, though, I've been thinking for a long time about a system for the inner solar system, where the solar wind is more intense, that would selectively capture the solar wind, while also generating power. So you could collect large amounts of helium or hydrogen, depending on what you prefer, and also produce antimatter with the energy excess, for your interplanetary and interstellar propellant needs.

>>5292415
Water's good for top-performance hydrogen fuel, but the common soil is full of aluminum oxide, and a slurry of powdered aluminum in gelled liquid oxygen is also quite adequate as rocket fuel.

Aluminum can also be used to make thin foils for solar sails and solar reflectors. While solar sails are kind of wimpy, you can get insane Isp out of a big solar reflector/generator used to accelerate just about anything for reaction mass, and it's easy to control the direction of thrust, too.

Lunar ice would be a convenience, but it's not essential.

>>5292345
You forgot nickel and titanium. Moon has shitloads of them, on surface, readily available.

Moon mines will completely change our mechanical engineering, you mark my words.

>>5292473
> 2012
> not considering metallic sodium as a fuel for plasma rockets

Personally I'd limit water mining on Moon for now. Hydrogen & oxygen are good, but we'll forget that we ever used used them as rocket fuel for bodies without the atmosphere in 200 years or so. Scarce moon water may be depleted by then.

Fuck yeah SpaceX!

>>5292703
Sodium is inferior to aluminum as fuel, and not really plentiful on the moon.

>>5292454
You speak truth. Active stabilization will take over pretty much everything on Earth very soon. Why avoid it in space, where it was probably used earlier than in any other place?

>>5292732
Everything built in space will need some form of RCS. Can you imagine giant stations with small streams of gas coming out at various intervals? Would look beautiful.

>>5292725
I spoke of electric plasma rockets. They need ionized medium to accelerate, and sodium is very easy to ionize.

There's no need to use chemical rockets on Moon, really. Payloads can be driven to LMO with electromagnetic launchers only a couple of kilometres long, and that's if you want no more than 2-3 g of acceleration. I don't remember actual number, though, and I am to lazy now to look up or calculate Moon's escape velocity.

>>5292749
Fuck yeah, steampunk returns!

>>5292768
With any kind of catapult, you still need rockets, for circularization if nothing else.

A catapult would be something for an advanced level of lunar development, just to make things more efficient, not a basic facility for the pioneering phase.

Musk appreciation thread? Richard Branson is fine too

Has he made in progress with that electric jet idea yet?

I am fucking excited... I dream of the day when humanity can split into a hundred different branches based on the direction they travel. We could visit Earth in only a hundred years and observe our "ancestors" in their natural habit (all the ones that stayed).

I dream I dream I dream. The stars. I long for the adventure!!! To BOLDLY GO WHERE NO ONE HAS GONE BEFORE! Yes, yes I am fucking excited. Endless possibilities... for every ancient sailor that turned the bow of his ship towards the unknown horizon...

The dream is Elon Musk represents the best of what it means to be a human being.

Plus picture related
it's his wife

>>5293129
God DAMN. Fuck you, Elon.

>>5293174
s'cool, bro. They divorced. He has five sons from his previous wife, though. That was one of the pressures on him to put five seats in the back of the Tesla Model S.

>yfw his sons continue the dynasty, each taking their own kickass technology to fruition.

>>5287717
Yes, I am unreasonably excited about Elon Musk's ventures:

* PayPal, to build his internet fortune
* SpaceX, because NASA wasn't getting to Mars fast or cheap enough for his tastes.
* Tesla and SolarCity, to get the US off of fossil fuels.

The only thing that could make him more insanely cool would be to get behind LFTR for base-load power generation.

more fucking cool rockets up in this thread

>>5293280

>lose an engine 82 seconds into flight
>complete the mission anyway
>AS DESIGNED
>LIKE A BOSS

>>5293234
btw, that picture was taken in his private jet. He uses it to hop between the two companies he runs, SpaceX and Tesla.

This is Elon standing next to the Merlin 1D. It was designed for cheaper manufacturing (explosive forming of the engine lining, fuck yeah!) and reusability, using lessons learned both on the current engine and from building the Tesla production line.

>/sci/ raging over an engineer

How ironic given the usual appreciation that engineering gets on /sci/!

Musk is might cool but you guys are acting as if he literally designs and builds the entire things himself.

>>5293438
He has a harder job: hiring an exceptional team, retaining them, and being a hard-nosed perfectionist on the production line. He is mostly an exceptional businessman, keeping these companies solvent despite HUGE up-front development costs and uncertain returns. Sometimes I wonder whether Steve Jobs died because Elon stole his Reality Distortion generator...

>pic: the first Falcon 9 strongback falling apart just after launch. oops. amazingly, no one used this to attack SpaceX.

This site is relevant:

http://shitelonsays.com/

>>5293258 The only thing that could make him more insanely cool would be to get behind LFTR for base-load power generation.

LFTR is imaginary technology that will cost way more than Elon can afford.

>>5292078

SpaceX got there first.

Boeing and Lockheed have a lot of other shit on their plate to deal with. There is no doubt a metric fuckton of bureaucracy in this companies regarding investments poking on the billion door.

SpaceX can dedicate all of their attention and resources to their primary objective and it has worked so far. They've resupplied the ISS successfully!

This doesn't mean other companies are out of the picture. The idea of orbital/sub-orbital commercial flights is a great big dick that wants to fuck their markets.

When Reaction Engines complete their proof of concept to the ESA their funding will explode and other companies better bite the pillow because they'll be going in dry.

>>5293500
>http://shitelonsays.com/

Haha, awesome.

>>5293500
>>5293908

viral marketing

>>5293910

Fuck off, that's a lie and even if it's not IDGAF

>wanting space development
How about you fix your problems on Earth first?

>>5293927

How about you shut your goddamn whore mouth Mr Bumfucker?

>>5293927
>1492
>wanting faster trade routes
How about you fix your problems on Europe first?

>>5293996

I'll have them launch a cable for my space elevator and put them out of business

>>5287902
>I don't imagine they'd actually fly down ass-end forward with the rockets burning the whole way.
That's not the ridiculous part. The ridiculous part is wasting shitloads of propellant trying to make your first stage do a U-turn in outer space. Might make sense for the boosters, or a small first stage of a 3 or 4 stage rocket, but not for this. It just costs you too much valuable payload capacity.

>>5291569
Skylon is fucking retarded. There's a reason HOTOL was dropped like a hot potato; airbreathing engines are just too fucking heavy to lug all the way to orbit.
http://forum.nasaspaceflight.com/index.php?topic=24621.195;wap2
>MFW Skylon, with it's la-la-land structural weight figures, could carry more payload to orbit with conventional rocket engines than it would with those P.O.S. SABRE engines

>>5294416
>surely they have not thought of an issue and balanced the pros and cons of different approaches over their years of dedicated work on this, while i can spot the flaws at a mere glace, while not even being an expert in the field as they are.
>comon guys, its not rocket science

>>5294467
I don't need to weigh the pros and cons. NASA did it for me decades ago.
>http://ntrs.nasa.gov/search.jsp?N=0&Ntk=All&Ntt=flyback&Ntx=mode%20matchallpartial%2
0
>All those rejected proposals

SpaceX is doing some pretty cool stuff.

I wish I could get them out of my head as competition with NASA. NASA is near and dear to my heart so seeing other things doing cool space stuff makes me see them as bad guys.


Its fucking stupid I know.

>>5294518
NASA cited for coherent practical decisions. My sides.

>>5294518
This is the same NASA that decided to build a reusable "space truck" launch system to reduce launch costs for a high volume of traffic, and ended up with the space shuttle: a vehicle that cost more to refurbish after each flight than a single-use rocket of similar payload would cost to build, and which also required more fuel and more elaborate ground facilities, could only rarely be flown, and was fundamentally unsafe.

Then, when it became fully obvious that this was no "space truck" and would not save any money, or support a high volume of traffic, they built four more of the useless fucking things.

So, no, I'm not going to be terribly interested in what they were saying about why they couldn't do any better than they did with the shuttle.

>>5294563
>Implying they hadn't planned to build a fleet of Shuttles from the very start
>Implying the Shuttle didn't support a high volume of traffic

>>5294461

Would you like to point us to anything particular in that thread? Rolls-Royce and BA engineers are fairly qualified people and I would be tempted to say they have decent judgment.

Found a documentary about Skylon / Reaction Engines that I'm about to watch.

First aired Sept 12 2012 on BBC4

http://www.youtube.com/watch?v=NNtr1PuhlPI

>>5293877
He's expressed interest in LFTR's. And also said he cant afford them... Yet

>>5294461 airbreathing engines are just too fucking heavy

This is not the reason.

>>5294856
>Modern afterburning turbofan engine: <10:1 thrust/weight ratio
>SABRE: Allegedly 15:1
>Liquid rockets: Typically ~80:1
>Solid rockets: Up to 400:1

>>5293904

>SpaceX got there first.

Or rather, SpaceX was the first opposition to the incumbents who were pretty comfy with the huge contracts they were winning over from NASA. Why compete for $0.8B contract when you and your opponent can both manage to get $2B contract instead?

>>5290571


>Elon: I'm hopeful we will send our first person to Mars in the 10-15 year time frame
>BBC: As soon as that?
>Elon: Yes, we can't wait too long. I don't want to be so old that I can't go.

Holy fuck, this actually gives me some hope. God speed you musky bastard.

>>5294882
>focusing on something that's beside the point of it all
Expand your horizons, at least beyond your own navel.

>>5294882

This is not the reason either.

Horizontal take off does not require the same thrust as vertical take off.

>>5294901
The point is to build a reusable SSTO, no?

So how about ditching the mediocre vaporware and building something realistic instead? Hell, they'd be in orbit by now if they weren't delusional crackpots stuck on a failed technology.
>>5294919
>Implying I'm talking about increasing thrust
>Implying I'm not talking about reducing weight
Get with the program.

THE FREE MARKET FIXED IT

>>5294936
Like I said, it's about more than that. Read up on it a bit, would you kindly.

>>5294949
>THE FREE MARKET FIXED IT

But SpaceX's money comes from NASA.

>>5294949
>THE FREE MARKET FIXED IT

But SpaceX's money comes from NASA.

>>5294936
>>Implying I'm talking about increasing thrust
>>Implying I'm not talking about reducing weight

You're not understanding what you're saying.

If you're talking about a ratio then you're talking about both parts of that ratio. Weight isn't the problem.

Problem with HOTOL was a center of gravity and center of pressure mismatch, causing instability as fuel was used up. It's explained in this documentary. They say that problem has been solved by putting the engines on the wing tips.

Documentary also shows the Sabre engine passing a major milestone with its cooling system.

>>5294751 http://www.youtube.com/watch?v=NNtr1PuhlPI

>>5294936
Not the guy you're debating but
>>Implying I'm not talking about reducing weight
>Implying using air as an oxidizer does not reduce weight.

>>5294958
>Implying I haven't read thoroughly about Skylon
Please, tell me this hidden purpose that Skylon will somehow fulfill better than a conventional rocket.
>>5294994
>Weight isn't the problem.
But it IS when your new, supposedly game-changing technology can't even match the end-game performance of conventional rocket engines.

Read the link I posted above. It makes it pretty damn clear that Skylon's usage of the SABRE engines really just doesn't pencil out.

>>5295015
It reduces launch weight, but increases empty weight. Net result: even less payload capability than if you were to simply reallocate propellant tankage and build the thing with pure rocket engines instead.

>>5295020
The internet says so, so it must be right!
If skylon can build a reusable SSTO they'll have a profitable cashcow, fuel is cheap. End of story.

>>5294990

Not only money, but also a lot of R&D and other technical help. It's kind of like NASA is funding SpaceX but now new developments within SpaceX are privately held and not accessible to the public anymore. If anything politically it worst than before.

>>5295024
>The internet says so, so it must be right!
If you can't follow his logic and derive the numbers he found, then you have no business even being in this thread. This is babby-tier rocket science. Tsiolkovsky's rocket equation. That's it.

>>5295037
What numbers?

>>5295037
>Tsiolkovsky's rocket equation. That's it.

The equation that says all reactant mass must be carried onboard applied to a partially air breathing propulsion. Good job anon.

>>5295041
Because all I see is some guy posting random questionable figures.

>>5295020
http://www.bbc.co.uk/news/science-environment-13520948

>Dr Mark Ford, Esa's head of propulsion engineering, told me:

>"We've not looked at everything; we've focussed on the engine and the [Skylon's] structure. But from what we've seen so far, we can't identify any showstoppers. It's certainly a very interesting approach and it's a very interesting technology, let me put it that way.

>"It has certain advantages over other approaches which have been proposed. As I've said in the report, namely that you can test the engine on the ground; you don't need to do an air launch or anything expensive. And also, it appears to have a high thrust to weight ratio, which again is another positive. So, it's quite an innovative technology if it works."

>high thrust to weight ratio

ESA head of propulsion engineering vs RobLynn

>>5295041
http://forum.nasaspaceflight.com/index.php?topic=24621.195;wap2
>Replace Sabres with 3x SSMEs to reduce weight
>New on-orbit mass w/ same payload: 46 tons
>Assumed delta-V: 9.2 km/s (pessimistic, since he's basically ignoring the benefit of the wings for the time being)

>Resulting initial mass req'd: 418 tons, or 1040 m^3 of propellant
>Fits in Skylon's tankage with room to spare

>>5295053
>high thrust to weight ratio
He's comparing it to other airbreathing engines, which are all positively ABYSMAL compared to pure rockets. See [>>5294882]

>>5295057
It's a concept testbed. What the hell do you expect from it?

Would you have abandoned the use of rockets because the first rockets were more expensive, hazardous and unreliable than bombers?

>>5295055

Is he directly comparing fuel volume and not specific volume?

Skylon has been designed to use very large tanks but filled to a lower pressure to reduce stress in the vehicle structure.

>>5295069
Going by Wiki to calculate expected Skylon fuel capacity
http://en.wikipedia.org/wiki/Skylon_%28spacecraft%29

Loaded Weight - 345000 kg
Empty Weight - 53000 kg
Payload - 15000 kg

Fuel = 277,000 kg

Going by figures found http://forum.nasaspaceflight.com/index.php?topic=24621.195

3 SSME imaginary thing
1040m3 capacity @ 358 kg/m3

Fuel = 372,320 kg

If we go by the sought after $500,000 ticket price to Mars, and we have 10-15yrs to save $$$ for it, how would the average person save up enough for this? I'm probably looking at starting a lab position at $20k-$30k/yr. $500,000 isn't a huge amount of money, but it would require some serious effort to secure.

>>5295027
SpaceX and other private companies are doing what NASA can't do anymore: risky long term projects and cost reduction. NASA is finding itself hogtied politically, to the point that they cannot build cheaply any more. Constellation showed that even a good project can be toppled by shifting political winds, and there is a good chance that SLS will go the same way, wasting billions in the process.

SpaceX's innovation is not in their technology (yet!) but in choosing low cost routes through vertical integration and flat management structure. The same rocket built by NASA would have to use contractors from a dozen more states and use ATK solids from Utah in order to be politically viable, thereby tripling the costs. And the government is too risk-averse to develop cost-saving technologies like the Grasshopper fly-back reusable booster.


Did you know that the most launched currently active US rocket is also from a private company? Pic related.

Who will be our wayland company ? SpaceX or Planetary resources ?

>>5295617

I don't think it's fair to say NASA can't build things cheaply or even that they should be aiming to be cheap. They have a lot on their plate and it's all groundbreaking new stuff. Why should they waste their time and limited resources on something simple like launching?

I just wish JWST would hurry up ;_;

>>5295069
>Skylon has been designed to use very large tanks but filled to a lower pressure to reduce stress in the vehicle structure.
So has almost every other liquid-fuel rocket stage since 1942. That's what turbopumps are for.
There's a point where the weight savings of this cease, though, as thrust and aerodynamic loads surpass tank pressure as the most significant stresses. Around this point, tank pressure goes from nuciance to major structural asset, as it helps rigidify the rocket. Karel Bossart's balloon tanks, like on Atlas and Centaur, epitomize this.

By reducing pressure even further, MRL has only necessitated the addition of more internal structural members to maintain integrity. I just can't see them actually achieving any real gains by doing this, since doing the EXACT OPPOSITE is what made Centaur into the highest-performing upper rocket stage of all time.

>>5296130
>MRL
Oh, what the fuck?
I mean REL.

>>5295955
>Why should they waste their time and limited resources on something simple like launching?
Because NASA already has more time and ideas and plans than they know what to do with, and they're going to have to pay for their launches no matter who provides the service.

If they can figure out a cheaper way to launch payloads than commercial launch services can, then they should do so. If not, then they're better off paying those funds to someone who can make their dollar go further.

>Overtures cumbuild

>>5295955
>something simple like launching
Launching is THE technical challenge. It's both the hardest thing and the most important thing.

If LEO launch had a success rate comparable to commercial airline flights, and $10/lb launch costs, people would do stuff like NASA's missions for school projects.

99% of the non-launch challenge is doing otherwise easy stuff with the minimum of mass, because launch costs are so high.

>>5296347
>Launching is THE technical challenge.
I dunno, man... Things like rendezvous, docking, deep-space navigation, aerocapture, etc. seem pretty damn challenging to me.

And of all spaceflight-related deaths, most seem to happen on reentry, suggesting that's pretty challenging too.

>>5295794
Virgin Galactic, because they're the launch company for Planetary Resources

>>5296828
They ALL get easier when you can put more mass in space.

Rendezvous and docking really aren't that hard. They're high school physics in the purest form. The primary difficulty comes from the low margin for error due to limited propellant load, due to the cost of launching stuff into space.

Deep-space navigation is really not hard. Space is very transparent, and the math of motion in space is child's play. The primary difficulty is limited instrument and propellant load, due to the cost of launching stuff into space.

Aerocapture is an answer to seriously inadequate propellant loads, due to the cost of launching stuff into space.

Re-entry is relatively easy. The only real re-entry failure was Columbia, and that was due to damage on launch. Of the two Russian "re-entry" failures, one happened prior to re-entry (opened a valve in space and let the air out), and the other after (parachute failure). The first was really a launch failure, and the others could have been made much less likely with higher safety factors which were infeasible due to the cost of launching stuff into space.

>>5296894
They've just started working on orbital launch capability, and their target is to achieve $100,000/kg in 2016.

SpaceShipOne was cute, but it was basically optimized for crossing a meaningless XPrize finish line, and the approach had no real potential for orbital flight.

Virgin Galactic isn't a serious contender, except in the field of suborbital tourism.

SpaceX should establish on the moon first as has been bought up a couple of times in this thread. Would be a great place to launch from LEO, as well as providing masses of resources. Also lots of space for building/testing.

From there ships/drones can be sent to nearby asteroids planets for resources and scouting.

>>5297073
SpaceX is a rocket company. They should focus on building and operating rockets, and not plan on going into competition with their potential customers.

Providing a reliable and cost-effective high-volume launch service is ambitious enough. If someone does it, the rest will happen.

>>5296961
>Rendezvous and docking really aren't that hard. They're high school physics in the purest form.
So is launch. Hell, it's even EASIER, as far as navigation goes.
>The primary difficulty comes from the low margin for error due to limited propellant load
Lol, okay, Buck Rogers. Whatever you say.
>the math of motion in [deep] space is child's play
Again, not nearly as much so as at launch.
> The primary difficulty is limited instrument and propellant load, due to the cost of launching stuff into space.
Instrument weight is virtually a non-issue. It's the precision of these instruments that's a challenge in itself.
And again, no realistic amount of propellant is going to make up for pisspoor navigation. If you launch for Mars outside a year before an optimal launch window, you're going to take a fucking decade and an inordinant amount of propellant just to sync orbits with Mars.
>Aerocapture is an answer to seriously inadequate propellant loads, due to the cost of launching stuff into space.
Pissing away propellant when there's a perfectly satisfactory aerobraking opportunity is as retarded as it gets.

I bet you think drifting is the fastest way around a racetrack, too.

>Caling Soyuz 11 a "launch failure"
10/10, I raged.

>>5297134
>So is launch. Hell, it's even EASIER, as far as navigation goes.
Launch isn't a navigation problem, it's an issue of extreme high-performance engineering. It's simple in principle but making it efficient is a deep technical challenge.

The rockets you need for rendezvous aren't technically challenging or expensive, and it's done in an ideal environment with the simplest possible physics. Docking is literally just hooking two things together with a tight seal, again, in an ideal environment with the simplest possible physics.

There's a reason that NASA has been able to do these other things with reasonable competence, but has only been able to achieve launch with extreme inefficiency and murderously poor reliability: launch is by far the hardest part.

There's no fundamental theoretical objection to high-volume $10/lb orbital launch, but NASA's best effort at low-cost, high-volume orbital launch did not go below $25,000/lb, and 2 of 5 vehicles failed spectacularly, killing all crew and passengers.

>>>The only real re-entry failure was Columbia, and that was due to damage on launch. Of the two Russian "re-entry" failures, one happened prior to re-entry (opened a valve in space and let the air out), and the other after (parachute failure). The first was really a launch failure, and the others could have been made much less likely with higher safety factors which were infeasible due to the cost of launching stuff into space.
>>Caling Soyuz 11 a "launch failure"
>10/10, I raged.
>List of three things. "The first was really a launch failure" obviously refers to the second of the list, and not the first, which had previously been noted to be a failure due to problems with the launch.
Whatever you say, chum.

>>5295794
Martin Jetpack, based solely on the vaguely similar logo.

>>5295794
Martin Jetpack, based solely on the vaguely similar logo.

>$10/lb

$1500 for a skinny person?

>>5297453
Well, in this case "payload" has to include some kind of vehicle. To take up a 150 lb person, sustain their life in space, and bring them back down safely, you'd probably need to pay for a ton (that's for each passenger in a fully-loaded vehicle).

If it was a one-way trip, with facilities in space paid for separately, they could probably go up for as little as twice their weight.

Let's say $25,000 for a short LEO space vacation, $4000 for the first stage of emigration, and $10,000 for emigration to the moon, assuming you've already got a job lined up that will pay for your accomodations.

Of course, $10/lb is very ambitious. $50/lb is much more plausible.

>>5297240
>Existing launch methods
>Inefficient
Did you even read OP?
>Murderously unreliable
Right, because cost-cutting is really going to help with that.

>>5297481
I'm just pointing out that's not at all 'like a plane ticket' as some people claim.

>>5297488
OP isn't about a NASA project. SpaceX is a private corporation. NASA is just one of their customers.

Congress stopped giving NASA money to develop their own launch options because they suck so much at it.

>>Murderously unreliable
>Right, because cost-cutting is really going to help with that.
A highly reliable reusable vehicle is essential for getting costs low. So yes: reliability and low prices go hand-in-hand.

Do you think a commercial airline would be able to provide low ticket prices if they had even a 1% flight failure rate?

>>5297240
>NASA's best effort at low-cost, high-volume orbital launch did not go below $25,000/lb
The space shuttle was a manned launch vehicle, comparing it to unmanned rockets is not legitimate. The orbiter itself is the payload (like dragon is for falcon 9) so costs are less than a fourth of what you claimed.

> 2 of 5 vehicles failed spectacularly
Nonsense statement, the failure began in the nonreusable sections in both incidents so only 2 of 135 vehicles failed which is a very reliable launcher.

>>5297519
It's not hard to spend $1500 on a plane ticket.

Anyway, even if it's not as cheap as a plane ticket, just being available like one and reliable like one would be world-changing.

A $1,000,000 space vacation might be very popular among the rich.

A $100,000 moon trip would be accessible to the bulk of the first world population, and people might have a lot more money once commercialization of space gets rolling.

Frankly, while the peak of the first generation might run on kerosene and cost $50/lb for LEO launch, the second generation might run on liquid hydrogen and oxygen produced by soaking up peak time excesses of cheap solar power and cost $1/lb to LEO.

>>5297588
You can already buy a seat on Soyuz.

>$1/lb
There will always be maintenance, parts and vehicles will need to be replaced. Such a cost reduction is totally unforeseeable. These numbers are pulled out of nowhere.

>>5297588
>while the peak of the first generation might run on kerosene and cost $50/lb for LEO launch
Even SpaceX's generous estimates put the real figure at $1286/lb. Your estimates are fantasy.

>>5297558
SRBs are reusable up to 20 flights.

>>5297558
>The space shuttle was a manned launch vehicle, comparing it to unmanned rockets is not legitimate.
It was meant to compete with unmanned rockets. People only started talking like this after it was demonstrated to be such a miserable failure.

At the time, a human crew was an important control system, not just part of the payload. If the shuttle had worked as intended, it would have been a real "space truck" with cost effectiveness unsurpassed by anything that has been done in the real world.

>The orbiter itself is the payload (like dragon is for falcon 9) so costs are less than a fourth of what you claimed.
Falcon 9 can launch other payloads than the Dragon. The shuttle could not launch without the orbiter, and the orbiter was never meant to be the "payload".

Note that the Dragon was designed from the beginning as a passenger vehicle. The resupply missions, though they serve a purpose, are only a series of tests for human rating. There would be no sense in bringing a reentry vehicle on an unmanned resupply mission, except to test it.

>the failure began in the nonreusable sections in both incidents so only 2 of 135 vehicles failed which is a very reliable launcher.
Even if you had your facts straight, that would be the most ridiculous rationalization I've ever heard. Anyway, the SRBs *were* reusable. Claiming that the fuel tank was a "vehicle" is absurd.

>>5297588
>A $100,000 moon trip would be accessible to the bulk of the first world population

>>5297641
>Even SpaceX's generous estimates put the real figure at $1286/lb.
I have no idea where you're getting this ridiculous number. Their current advertised price for launch services available from them right now is is under $1900/lb.

Maybe your ~$1300/lb is their estimate for the non-reusable Falcon Heavy, and it would be by no means "generous".

The estimate for the first few launches with the Falcon Heavy with reusable boosters is $500/lb, and Musk has stated that their own first-generation fully-reusable launch system could go down to $10-20/lb with a sufficiently high launch volume (I think that's pushing it, and this system will never go under $50/lb before being replaced). Without a sufficiently high launch volume, the cost of the vehicles couldn't be amortized over many flights, so low volume launches would be stuck in the $100-500/lb range.

>>5297618
>>$1/lb
>There will always be maintenance, parts and vehicles will need to be replaced. Such a cost reduction is totally unforeseeable. These numbers are pulled out of nowhere.
At $10/lb, the cost is mostly fuel. Solar power development could easily bring hydrogen fuel prices down this much. Furthermore, the engines can be made significantly more efficient, particularly at liftoff.

Material science and manufacturing are also advancing, which is why SpaceX has been able to do so much with simple designs. As our fundamental technical capabilities increase, everything gets better, easier, and cheaper.

>>5297678
Do you know what people spend on education, cars, and housing in the first world?

If you could reliably get a six-figure salary (plus accommodations) on the moon (and I can't see jobs there paying any less), you'd have little trouble getting a bank loan for a $100,000 emigration.

>>5297678
>People mortgage houses for hundreds of thousands.
>People spend tens of thousands of dollars (upto hundreds of thousands with interest) for education
>People spend tens of thousands for cars
>People spend tens of thousands for housing items (couches, TV, computers)
>etc...

>$100,000 once-in-a-lifetime-vacation is suddenly too expensive.

http://www.bbc.co.uk/news/science-environment-20510112
>Skylon spaceplane engine concept achieves key milestone
>Reaction Engines Ltd (REL) of Culham, Oxfordshire, ran a series of tests on key elements of its Sabre propulsion system under the independent eye of the European Space Agency (Esa).

>Esa's experts have confirmed that all the demonstration objectives were met.

YES!

>That feel when Elon Musk is the founder of real life Weyland Industries

>>5297775
You forget that most of those are paid with loans and others accumulate as time goes on, only a few people have 100k $ of spare cash lying about.

>>5297775
>mortgage, education
>vacation
ROI

>car
>household items
>$100,000 each
>available to most people in the US
for real?

LANDING ENGINES ON EVERYTHING
Does Elon have a personal vendetta against parachutes or something?

>>5298671
http://www.skymania.com/wp/2012/11/major-boost-for-skylon-spaceplane.html/7216/

>

British engineers have made the biggest breakthrough in flight technology since the invention of the jet engine. They have successfully tested a new propulsion system that could power a space plane to orbit and also cut an airliner’s journey times from London to Sydney to less than four hours.

I'm so fucking excited

>>5298910
>They invented the internet
No, that's just plain wrong.
>They they they they
No, English citizens did all those things, most of which are dead now. England and its current citizens have absolutely nothing to do with it

Shit, maybe a moon base in the 2020s isn't as far fetched as I thought. I hope we're at the brink of a revolution in space travel.
About fucking time.

>>5298902
The stages don't just fall in thick atmosphere. They move fast as fuck thrugh thin atmosphere, and then hit the thick atmosphere.

What happens is that the stages are destroyed before they hit the ground, it's not viable to use parachutes to break them.

>>5298925

>No, that's just plain wrong.
That isn't wrong. Tim Berners-Lee invented it, everyone else just developed it.

>No, English citizens did all those things, most of which are dead now. England and its current citizens have absolutely nothing to do with it
So? They were still British you moron.

>>5299337
Why not successive drogue chutes?
Powered descent really seems like a waste of fuel.
Even using descent engines to slow the stage down enough to deploy a parchute seems like a better idea.
>>5299383
Tim Berners-Lee invented the World Wide Web, not the Internet.
They're different things, invented in different decades on different continents.

>>5299443
Parachutes have a pretty high failure rate, and are just not good for landing at a specific destination.

>>5291952
>replacing commercial airline routes with sky bridges held up by helium balloons

That's...that's...AWESOME! Give this man some money, I want a working prototype by 2014!

>>5299443
I agree with the chutes, especially in earth's atmosphere

however attributing such a massive engineering feat to a single person is utter retardation

"father of the telephone" "father of the radio" "father of the laser" "father of the tv" "father of the internet" "father of the www" you need to realize that all this is bullshit. if they hadn't existed we wouldn't feel a significant difference.

this also applies to the other nigger you responded to.

>>5294990
>But SpaceX's money comes from NASA.

That's not even true if you based it on the amount of contracts. NASA makes up less than a third of their contracts. People somehow forget that there's lots of satellites up there and many more each year. Do you think they get up there magically?

>>5300518
I thought they flapped their solar panels.

>>5299443

Have you considered that the fuel used for powered descent is less than the amount required to lift your parachute device into space?

Chutes don't work well on really heavy things because huge forces.

>>5301089
Interadasting. Very valid point.

Wouldn't it cost almost as much energy to land it safely as it would to send it into orbit ?

all this talk about mining the moon!

>removing mass from the object that creates tides
>messing with a 4.5billiom year old system

ya huh typical dumbass humanity thing to do

>fucking with your planets natural sattelite..

>>5301885
I really can't tell anymore where trolling ends and stupid starts.

>>5298925
It's meant to be a troll image.

>>5301887

then you are a fucking idiot

go learn what happens to the gravity of an object when you remove mass

then go research the relationship between the moon's gravity and the earth


maybe then you will realize why its a dumbass idea to mine the moon, move the moon, effect the moon in any fucking way if you want life to continue as is on earth

ignorant pleb

>>5301891

here's a clue:

the moon is pulling all the water on earth towards the equator

if you reduce this effect then guess what happens? flooding near the poles, that's right!

>>5301899

those 24 hour days you all love so much? moon in action

gravity in action

>>5301891
No, I can't tell if this post is trolling or stupid either.

>>5301887
sums up /sci/ pretty well

It had some merit, like disallowing some unhealthy people from reproduction could prevent their genes from being passed on. However there were also many human rights abuses. Also, intelligence does have a genetic component and some researchers think humans are getting genetically dumber.

http://abclocal.go.com/wls/story?section=news/health&id=8883776

The future of eugenics is bright due to genetic engineering.

>>5301891

The moon is fairly big.

Mining isn't going to remove a substantial amount of mass. Most of it is useless and will be returned.

You're stupid.

0/10

>>5302587
"moon is fairly big"

Moon is way smaller than earth DUMB FUCK

>>5302634
He never said anything about its size relative to earth.

Oh, and the moon is fairly big.

>>5302634

The amount of material we currently could take from it would be negligible ELEGANT GENTLEPERSON

>>5302683
>elegan/tg/entleperson
Wait... was this about neutronium golems eating the moon?

>>5298910

Skylon is a bunch of quacks running a startup who talk a big self promoting game but whose efforts are to ensure they receive a modicum of funding to sustain their dead end career jobs in a backwater dead end field that once seemed promising and that they've sunk the better part of their lives in.

>British engineers have made the biggest breakthrough in flight technology since the invention of the jet engine.

That's them, describing themselves, in their own press release.

*Some evidence of unrelated general quackery:

In a self-published book[2] co-authored with Mark Hempsell, an engineer at the University of Bristol, [Alan] Bond claimed to have deciphered an Assyrian clay tablet dated to 700 BC that they argued might describe an asteroid strike causing a landslide at Köfels in Tyrol in 3123 BC. They relate this to the destruction of Sodom and Gomorrah.[3] The landslide is normally dated to about 9800 years ago,[4] long before the tablet was recorded and over 4500 years before the Bristol researchers' date.[5] Bond and Hempsell have suggested that there was contamination, a claim that has been denied by other research.[6] The impact theory had already been proposed in 1936 by the Austrian scientist Franz Eduard Suess and later on by Alexander Tollmann, who hypothetized impacts in around 7640 BC and 3150 BC, respectively. The question of whether an impact caused the landslide has been researched by others and no evidence was found for an asteroid, meteorite or comet, and geologists consider it to have been caused by other factors such as 'deep creep'.[7]

>>5302730
Jelly as fuck.

Also, nice ad hominem, I guess we should dig up some retarded 4chan post you've made(like this one) and discard your career entirely based on that one instead of your other credentials(though in your case, you probably have none)

>>5302765
He's got a point, though, that this:

>>British engineers have made the biggest breakthrough in flight technology since the invention of the jet engine.
>That's them, describing themselves, in their own press release.

...does not sound like particularly sane people.

The idea of a hybrid airbreathing/rocket engine is hardly a new one, and it's not like they've actually made one that works.

>>5302791 >and it's not like they've actually made one that works.

Well what they do have is a cooler that takes 1000ºC, Mach 5 air and cools it to -140ºC in 0.01 seconds.

The rest is comparatively easy.

This is revolutionary if it works, I'm not sure you can possibly question that.

>>5303385

>This is revolutionary if it works, I'm not sure you can possibly question that.

Or it could go nowhere because it doesn't have significant real world practical applications as opposed to deluded hype.

>>5302634

Are you sure about that? Venus is about the same size as the Earth, but clearly tiny compared the big moon in the sky. That's why we orbit the moon and not the other way around.

>>5303385
>The rest is comparatively easy.
I wouldn't say that. I wouldn't say that at all.

They're a long way from making a complete engine, let alone a complete spaceplane, and the projections they're making for the rest of the spaceplane are far beyond anything anyone has done.

>>5303455
The moon orbits around us. It's the sun that orbits around the moon.

>>5303423
>incredibly fast cooling and distillation of hypersonic hot gases doesn't have significant real world applications
Doe you realize how much stupid you just managed to fit into one post?

>>5304278
Are you making a joke?

They only did this with a large, stationary ground-based apparatus. Are you seriously saying that you think there's a lot of application for cooling hypersonic gasses for brief periods in a laboratory setting?

>>5304348
You're really, seriously insisting there isn't?

I personally know a few companies in which this tech is talked about non-stop because it would be extremely useful for them.

>>5304350
>ludicrous claim
>no supporting argument
>alludes to special real-life connections that somehow prove claim
>appealing to authority of unnamed parties making unspecified statements
Yeah, I'm taking you seriously.

>>5304278
>>5304361
Also: they aren't distilling anything, you utter retard.

>>5304361
An you're appealing to... absolutely nothing.

Also, I'm claiming that this new, efficient cryotech is very useful for business purposes, while you're saying that it isn't. Now reflect on that and try again.

>>5304348
>Are you seriously saying that you think there's a lot of application for cooling hypersonic gasses for brief periods in a laboratory setting?
>for brief periods in a laboratory setting

Not the other guy, but most new tech starts out this way anyway.

>>5304368
It's not "new, efficient cryotech", you utter dickwad. They're circulating helium gas between a cooling element and a pool of liquid nitrogen.

Their grand accomplishment is that the cooling element isn't icing up.

Seriously, this is nothing special, and you obviously have no comprehension of what they're doing.

>>5304417

Oh I'm sorry. I forgot you have your own aerospace company and are making technological breakthrough on a daily basis.

Do carry on.

>>5304436
>I might have just proven myself to be a complete idiot, and you might have just explained why this isn't any kind of breakthrough, but I bet you didn't build a rocketship today, so there!

>>5304361 troll

>>5304363 semantics

>>5304211 lolipops

>>5304447
>when I say wrong and stupid things, and people point that out, I say, "semantics" at them

>just because

>>5304446

Stop shitposting

>>5304368

You too

>>5304446

>imdonewithyouandyourshit

>>5304457
This, what you're doing here, is shitposting.

When two people are arguing over something, and one is being a fucking moron, and the other one is pointing out how the other one is being a fucking moron, with actual facts and clear explanations, only one of them is shitposting.

When someone jumps in and claims both of them are shitposting, now two of three people are shitposting.

Layman here.

Planetary Resources is the horse to bet on in the long term, because investments i orbital mining will eventually negate the importance of Terrestrial assembly/launch facilities.

>>5304596 >investments i orbital mining will eventually negate the importance of Terrestrial assembly/launch facilities.

No. While returns from mining may eventually be huge actually getting the whole project going requires seriously cheaper launching and "trucking" capability.

The ISS has a /tiny/ fraction of the mass you will need with mining equipment.

>argue with someone
>go to sleep
>come back a day later to find out the other guy has kept on arguing with other people and the argument did, predictably, devolve into namecalling
Which rocket scientist pissed in your morning cereal to make you hate new rocket technologies so?

>SSTO Rocket
>Lands back on the earth
Do you realise how difficult this idea is? Try doing it in KSP first then come back.

>>5305197
I've done it six months ago. Stock parts.
Belly landing on the runway. Only the belly wings and engine bells detached.

Also, the space shuttle is already a step in the same direction.

>>5292238
>enjoying low gravity
>Americans would rather go to space than diet
I'm just joking, but i think it will get a good amount of puke before common joe starts "enjoying" 0g.

>>5305189
Nobody "hates new rocket technologies".

The Skylon is an interesting idea, and if it could be built and would actually work as planned, that would be great. But saying things like, "what they do have is a cooler that takes 1000ºC, Mach 5 air and cools it to -140ºC in 0.01 seconds. The rest is comparatively easy." is just ignorant and stupid.

They've done brief testing under ideal conditions of one fairly straightforward part of an extraordinarily ambitious project. The extremely light airframe surviving even one launch would be unprecedented. The reentry mode would be unprecedented. Reliable repeat operation of such a high-powered, complex, and lightweight rocket engine would be unprecedented. The fucking landing gear would be unprecedented.

The space shuttle was also an interesting idea, and even when it came out, it was still expected to operate like a commercial jet, reduce spacelaunch practically to the cost of fuel, and serve as the USA's ONLY orbital launch system. We all know how that worked out in practice: refurbishing the engines and repairing the heat shield cost as much as making a new disposable rocket, a whole fleet of them could only fly a few missions per year, and two of five vehicles were catastrophically lost.

The differences with SpaceX's system are, in the first place, they're already doing regular orbital launches with demonstrated competence, and secondly, they're making a disposable rocket reusable. Each failure of reusability is STILL the world's cheapest (per pound payload) orbital launch system. They could get it wrong over and over again, and still have a profitable, sustainable business which continues to incrementally lower the cost of orbital spacelaunch and support their continuing experiments with reusability.

>>5305529
I want a party palace on the moon, with a big glass window centered on the full Earth at the new moon.

Tits are going to look amazing in the low gravity. I wonder how girls will dance in one-sixth gravity.

On a completely unrelated note: the SpaceX Falcon rockets are named after the Millennium Falcon.

>>5305544

Unprecedented isn't a fair description for most of those you listed because they're so similar to regular aircraft and we have learned a LOT from the mistakes in the Shuttle. The guys behind Reaction Engines aren't taking any of this lightly. They've dedicated almost 30 years developing this and for the most part have been privately funded. They've taken lessons from their HOTOL project and every other space mission you can think of.

I think it's fair here
>Reliable repeat operation of such a high-powered, complex, and lightweight rocket engine would be unprecedented.

I can see this being the next great challenge, they're estimating a 2 day service interval. That sounds tough, if they can pull it off they deserve a giant medal. Material science has come a long way from the 70s when the shuttle was developed. I'm going to make a speculation that because the engines work with fresh, chilled air for a lot of the journey rather than pure rocket burn then this could help reduce wear.

Reaction Engines - Alan Bond lecture

This lecture is fairly technical and he discusses a lot of the issues that come to mind when thinking about this project. Very worth the watch.

http://www.youtube.com/watch?feature=player_embedded&v=2G-HPHNrrLQ

>>5305687
>Unprecedented isn't a fair description for most of those you listed because they're so similar to regular aircraft
With that level of blind optimism, SpaceX's reusable design is trivially equivalent to established rocket technology, and they should be 100% guaranteed to reach their $10/lb ultimate goal within a few weeks.

These things are "similar to regular aircraft" in the same way that a commercial jetliner is "similar to a paper plane". There are some similar principles involved, and a couple of similar superficial features, but everything else is different. The re-entry mode IS completely unprecedented. Nobody has tried to take off and land such a large, fast-moving thing on such flimsy landing gear before. Nobody has tried to carry such a load in such a light airframe, let alone at such speeds and accelerations, and for such a busy work schedule. Do I have to point out that the engine is still vapor and fairy dust?

This requires a half-dozen major technological breakthroughs to work. By my count, they have made about 0.02 of a major technological breakthrough.

>They've dedicated almost 30 years developing this and
...have not a single working vehicle or engine to show.

>I'm going to make a speculation that because the engines work with fresh, chilled air for a lot of the journey rather than pure rocket burn then this could help reduce wear.
That's a ridiculous speculation, because it's only "fresh, chilled air" at the intake, and it's still "pure rocket burn" at the exhaust nozzle.

>>5305529
I heard that trained athletes a most likely to be uncomfortable in 0g cause their sense of balance gets confused the most. Normal people are usualy fine.

>>5305743

You are exaggerating and taking extremes way too much.

>100% guaranteed to reach their $10/lb ultimate goal within a few weeks.

What the fuck, no.

> Nobody has tried to take off and land such a large, fast-moving thing on such flimsy landing gear before.

What makes you think it needs landing gear any better than the space shuttle or any other fuckhuge airplane? It's well established technology that will require some adapting, minimal concern.

>...have not a single working vehicle or engine to show.

They're confident saying the major problem with their design was the frosting of the cooler. They don't need a fully manufactured engine to know where the largest hurdles will be and now that they've solved this problem the next step is to build a fully functional scaled model to prove the jet to rocket transition. I'm happy to be swayed a little by the fact they're coming from Rolls-Royce and British Aerospace, if anyone is going to know jet engines and rockets it's these people.

>>5305743
>they should be 100% guaranteed to reach their $10/lb ultimate goal within a few weeks.
It has been said before but you ignored it. Their goal for a fully reusable falcon 9 is not $10/lb. It is a long way off but the only good estimate they ever gave is old and that was $1286/lb.
Stop pulling numbers out of your ass.

>>5305743
>This requires a half-dozen major technological breakthroughs to work.
Please list them with citations.

>That's a ridiculous speculation
As opposed to "100% guaranteed".

>>5305544
>Each failure of reusability is STILL the world's cheapest (per pound payload) orbital launch system.
This is not true. The ex-soviet launchers are still cheaper. And if a fully reusable falcon was destroyed you can bet that would cost more to replace than a current one.

The rest of your rant is just baseless claims.

>>5305544
> The differences with SpaceX's system are, in the first place, they're already doing regular orbital launches with demonstrated competence
Suck billionaire cock a little more. It isn't like we haven't had 50 years of research going on and it isn't like SpaceX isn't filled with NASA people.

Fucking fuck I hate the spacex dicksucking.

>>5305911
>>That's a ridiculous speculation
>As opposed to "100% guaranteed".
Are you an idiot? That was a comparative example of how ridiculous he was being. The point is that it's equally obvious that SpaceX's reusable spacelaunch system will not be a mature technology within a few weeks as it is that Skylon isn't "so similar to regular aircraft" that now that the precooler's working, the whole concept is likely to work.

Skylon is a crazy hybrid of aircraft and rocket which must overcome all the difficulties of both, and new ones that arise from the combination, with novel solutions that can't be drawn from the experiences of either due to very different operating requirements.

They've been trying for 30 years to produce only one of the needed components, and they have only now managed to make a feasibility test prototype of a lab version of one subcomponent of it. They have just announced three-year plan to attempt to build a non-flyable lab prototype of the engine.

There is absolutely 0 hope that the Skylon spaceplane will fly within 10 years. While the engine is under development, the spaceplane is still in the CONCEPT STAGE, and there is a very good chance that it will never fly. They've also presented a concept for a much less ambitious atmospheric aircraft based on this engine technology, and have claimed it could be developed in TWENTY FIVE YEARS. There is no timeline for Skylon at all.

Falcon 9 is an operating spacecraft which has flown several successful and productive orbital missions, including sending what is basically a vehicle for human passengers to the ISS. And they've already demonstrated a production rocket motor on a production first stage doing a takeoff, hover, and landing, proving that the main part of their working space rocket is capable of landing and reuse with only slight modifications.

>>5305896
>the only good estimate they ever gave is old and that was $1286/lb
You never offered a source for that, I gave the source for the $10/lb claim in OP, and I've pointed out before how the $1286/lb number was almost certainly for a non-reusable version of the rocket, since it's in spitting distance of their current prices for the single-use version of the Falcon 9.

>>5305925
>The ex-soviet launchers are still cheaper.
Nope. SpaceX is already advertising the lowest per-lb price in the world, and have made contracts at that price.

Falcon 9 1.0 was close to being the cheapest, Falcon 9 1.1 is the cheapest. Falcon Heavy will cost about half as much as its nearest competition even with no reusable components, and may have its first test flight next year. If the flyback boosters are ready (and it looks like they could be), that will cut its price in half again.

>Are you guys excited about SpaceX?
Not really. I gain nothing from it.

>>5305997
>There is absolutely 0 hope that the Skylon spaceplane will fly within 10 years.
I completely agree. But I would say the same for a reusable falcon 9, it's not "slight modifications"

>>5306027
>SPACEX ANNOUNCES THE FALCON 9 FULLY REUSABLE HEAVY LIFT LAUNCH VEHICLE
> Falcon 9 is priced at $27 million per flight
http://www.spacex.com/press.php?page=18

Musk is talking out his ass when he talks about 100 times reduction. There will always be more than fuel: infrastructure, servicing, non-reusable components and replacement vehicles. That is not a plan that is just someone talking.

Soyuz costs about the same as falcon heavy. I'll find the numbers later.

>>5306149
Soyuz-ST (not the cheapest soyuz) flies at ~3050$/lb. That's cheaper than falcon 9.1 but not cheaper than heavy but that's the only rocket I've checked.

http://www.aero.polimi.it/~lavagna/bacheca/SOYUZ-ST.pdf

>>5306172
My bad. Total bollocks used lbs when the other one was in kg.

>>5306149
>I would say the same for a reusable falcon 9, it's not "slight modifications"
They already have a slightly modified Falcon 9 first stage taking off, hovering, and landing. All they did was add landing gear and reprogram it. Musk has stated a goal of having this test model go supersonic before flying back and landing safely before the end of 2012.

>http://www.spacex.com/press.php?page=18
"Reuse is not factored into launch prices."

It's as I previously said: that's not a price based on reusing the rockets.

Falcon 9 was designed from the start to be reusable, but they were initially going to just try for parachute descent with ocean splashdown and recovery, like the space shuttle boosters. If it worked: bonus. If it didn't: meh. They weren't counting on it, and it was never the main plan.

What they're working on now is a version capable of flyback and soft landing on the launchpad, with turnaround times in the single-digit hours.

>>5306172
>Soyuz-ST (not the cheapest soyuz) flies at ~3050$/lb. That's cheaper than falcon 9.1 but not cheaper than heavy
That's barely cheaper than the price PER KILOGRAM of the Falcon 9.1. You compared $/lb to $/kg. That's more than twice the price of a Falcon 9.1 launch, and significantly worse than Falcon 9 1.0 flights of the past.

And that's a price from 2002. It's unlikely that they've significantly improved the cost efficiency of their rocket, enough to offset a decade's worth of inflation.

>>5306227
Hence why I said I was wrong.

>>5306252
Yeah, sorry, I didn't understand your second post until after I made my post. Anyway, this makes your meaning clear for anyone else reading the thread.

To put this in perspective, a single Falcon Heavy with all stages and boosters fully reusable with flyback capability and "single-digit hours" turnaround could put the components for another ISS up in a single week, at a launch cost under $200 million, including the cost of constructing the vehicle (which, ideally, would still be in good working condition and able to do similar work next week at considerably lower cost).

The launch costs of the actual ISS exceeded $50 billion, it took two years to become habitable, and construction was still ongoing after four years when the Columbia disaster caused a major delay.

And they're designed for mass-production.. With Apollo-program-like funding, it's conceivable that a fleet of these things could put a CITY on the moon by the end of the decade.

News: they're switching to methane fuel.
http://www.flightglobal.com/blogs/hyperbola/2012/11/musk-goes-for-methane-burning.html

They're so serious about the reusable system that they're actually concerned enough about the fuel cost to redesign their motors and fuel tanks around a cryogenic fuel.

This would probably save less than 1% of their non-reusable flights, for a major expense in research and development, but it might cut their fully-reusable flight cost by half or more and extend engine life.

>>5307257
>http://www.flightglobal.com/blogs/hyperbola/2012/11/musk-goes-for-methane-burning.html

>However love cannot so easily be discarded and we are happy to report that Elon and Talulah are now back together again. Even better, they are both again engaged to each other and plan to remarry soon. As such,now that their Mars retirement plan is back on we at Flightglobal's Hyperbola blog wishes them both the best of both British and Martian luck for their future together.

>If we can just manage to get space flight really cheap, then space flight will be really cheap.
Wow that is exciting

>>5306532
MY SPACE BONER IS NO LONGER BOUND BY THE LAWS OF PHYSICS.

>>5307885

>>5306532

And now couple it with the use of Bigelow inflatable modules, instead of rigid ISS tin cans, which have several times the habitable volume per unit of mass you need to lift into orbit. A single 50 ton BA module could be larger than the entire ISS.

Space hotels, here we come!

Of course I am. Elon Musk is the man. 100 years later, he would be praised as Edison or Wrights are now.

>>5293927

I know this is a troll post, but the fact that I hear this bullshit so often really rustles my Jim-bobs.

>>5306080

>average public opinion.jpg

>>5295084

95,000kg of fuel goes a very long way to reducing overall cost, especially over multiple flights.

>>5304417
>Their grand accomplishment is that the cooling element isn't icing up.
>Seriously, this is nothing special, and you obviously have no comprehension of what they're doing.
"Everyone know that those wing shapes can lift heavier than air objects if moving fast enough. All the Brothers Wright did was constructing a motor light enough to propel their contraption. And not even that high, I might say. Seriously, this is nothing special, and you obviously have no comprehension of what they're doing."

This is you.

>>5308072
> science fans
why do you exist, seriously

the message, not the messenger, dude

>>5306532
http://www.youtube.com/watch?v=LYos3J_8D5Q
>Expendable rockets are for ladyboys and anti-intellectuals

>>5308643

i am actually intrigued by this one

>>5308643
The whole point here is that SpaceX is making a REUSABLE launch system, based on simply building a better disposable rocket and programming it to land the same way it takes off. They've demonstrated every necessary function (orbital launch, reentry, powered soft landing) and may very well succeed in putting them together into a fully functional demonstrator next year, and be providing launch services on fully reusable rockets in 2014.

Read the thread. The Skylon people have no timeline for actually building their spaceplane. They're basically saying, "Someday after we're retired, someone else might make it." They're on a three-year project just to build a non-flyable lab prototype of the engine, to see whether it can work at all, let alone the rest of the spaceplane design, which is pretty iffy even if the engine works exactly as claimed.

>>5308316
You too. Read the thread. The Skylon plan will, at absolute best, cut fuel consumption marginally, a couple of decades after half a dozen more practical reusable orbital launch systems have been put to regular commercial use. Comparing them to the Wright Brothers is utterly laughable.

Elon Musk is one of my idols. He uses his massive fortune to further human progress.

>>5308937
Fact: the writers of Iron-man 1 and Robert Downey Jr. inspired themselves from Elon Musk to define Tony Stark in the live action movie.

>>5308917
My point was to highlight your attitude when confronted to the engineering feat they managed to do with the cooling system.

Theoric plans exist of hybrid Hydrogen engine for space launch exist since almost 50 years. The blocking stop everyone else had tripped on previously was the management of the intake of the air at high temperature.

Reducing a success everyone else had failed to "nothing special" is either a blatant display of ignorance or trolling.
Their cooling device is no way "nothing special". They did what many had tried before but no one else had succeed.

The rest of the technology required to build Skylon is well known knowledge, worked on and resolved since almost 50 years. We are not inthe theorical zone anymore.

And one of the reason skylon has a way slower pacing of development is that they are working on a way lower budget than SpaceX.

>>5309114
>The blocking stop everyone else had tripped on previously was the management of the intake of the air at high temperature.
Oh bullshit.

>Their cooling device is no way "nothing special". They did what many had tried before but no one else had succeed.
Others haven't tried it, let alone "many". It's not that good an idea. What they're doing now may not work on an actual vehicle.

What they're doing now is rapidly cooling air from the (stationary, ground-level) intake with a big tank of liquid nitrogen, which is boiled off in the process. The Skylon's not going to have a big tank of liquid nitrogen on it, they'll be using the fuel, and by their own figures they'll be boiling off more hydrogen fuel precooling the air than they'll be able to burn with the air. The rest will be burned off in sort of a second-rate ramjet.

This is TERRIBLE for fuel-efficiency. It very nearly defeats the purpose of an airbreathing rocket. For all of this investment in complexity, you get a miniscule boost in fuel economy compared to a pure rocket. As others have pointed out, you could just put existing conventional rocket motors on the theoretical Skylon spaceplane (with all its wishful-thinking numbers), and you'd only have a modest reduction in payload compared to the best-case fantasyland scenario of the Skylon engines working exactly as wished for. The most likely outcome is that it will actually perform worse in practice than a simple rocket.

There's a very good reason these are basically the only people who have persisted with pursuing a precooling-based airbreathing rocket design past the initial analysis, and it's most certainly NOT that they're the only ones who can get it to work. This adds a lot of drag and wastes a lot of fuel, to save a little oxidizer.

>>5308917
Compared to SpaceX, Skylon has an other big advantage, other than a lower fuel consumption. It will only have two identical engines, whereas the current design of the spaceX (it's still that one, right http://www.spacex.com/multimedia/videos.php?id=3&cat=recent ?) requires three different engines and the requirement to work around the deformations caused by the stress of reentry to re-stack the rockets for a new departure.

This will dramatically increase the maintenance cost and complicate the engine-check-up procedure, especially for the engines used for the landing on re-entry of the top part.

Not to mention that after landing, the one-part design of the Skylon is almost ready to relaunch, needing only to be refuel and a easy-to-do change of the utility charge, whereas the SpaceX will require a precise operation of re-stacking and controlling the sealing between each part for a new safe departure, which mean more time on the ground where the rocket can not be exploited. For an equivalent amount of ships, this make Skylon again more profitable than SpaceX

All of this combined would clearly make Skylon the cheapest system and not just by a small margin. They might come a few years after SpaceX is in full commercial use, but it will still be a game changer.

And finally, I have always understood the suspicion on the capacity of the SABRE engine to not become a clogged block of ice. Managing to cool temperature without frosting was always the big "MAGICAL SUPER SOLUTION WE KNOWN BUT WON'T TELL HOW IT WORK" that would define whether or not the SABRE engine can actually work, for me.

But now that they have demonstrated their cooling technology is actually an exiting thing that practically function, I don't see what could prevent Skylon from becoming a real thing, if not for fund cutting.

>>5309194
>and by their own figures they'll be boiling off more hydrogen fuel precooling the air than they'll be able to burn with the air.
[citation needed]

>>5309194
>The Skylon's not going to have a big tank of liquid nitrogen on it, they'll be using the fuel, and by their own figures they'll be boiling off more hydrogen fuel precooling the air than they'll be able to burn with the air.
Isn't the whole point of the SABRE engine that the used hydrogen it burns with the air is enough to cool the air? (actually, via the helium, in HX4, that will the one to cool the air)

That's the base of their technology and I though the prototype engine they are building now and for the 3 next years would actually prove this is a workable solution.

>>5309211
>the current design of the spaceX (it's still that one, right http://www.spacex.com/multimedia/videos.php?id=3&cat=recent ?) requires three different engines
The Dragon capsule is basically only for crew transport (though it's being used for unmanned resupply missions as a way of testing its reliability). Most payloads won't involve it, and it's not important that it be capable of rapid turnaround and reuse.

So it's two engines, and one is simply the more vaccuum-efficient variant of the other. They are designed to be simple and reliable, and I don't believe that the plan is to do any maintenance between most flights. Elon Musk has been talking about turnaround time in the single-digit hours, which barely gives them time to run diagnostics, refuel, restack, and load the new payload.

>the requirement to work around the deformations caused by the stress of reentry
The first stage will not be doing any orbital re-entry. The second stage will be comfortably behind a heat shield. There's little reason to expect much in the way of "deformations caused by the stress of reentry".

>>5309224
https://en.wikipedia.org/wiki/SABRE_%28rocket_engine%29#Ramjets
"even simply cooling the air needs more liquid hydrogen than can be burnt in the engine core."

(there are references, but the Skylon people have since taken this information offline, and replaced it with "under construction" notices and stuff that's more vague)

>>5309235
>Isn't the whole point of the SABRE engine that the used hydrogen it burns with the air is enough to cool the air?
No. First of all, water can't come through the precooler. It would frost it up.

There has to be a bypass for much of the air that comes in the intake, if for no other reason than to carry the water rejected from the precooler.

Anyway, the heat capacity of liquid hydrogen isn't sufficient to cool enough air to combust it.

The excess hydrogen is burned with the bypass air in the "spill duct ramjet burners", which you can plainly see in the engine diagram on page 4 of the SKYLON Users' Manual 1.1:
http://www.reactionengines.co.uk/tech_docs/SKYLON_User_Manual_rev1-1.pdf

>>5309274
>https://en.wikipedia.org/wiki/SABRE_%28rocket_engine%29#Ramjets
"...The excess is dumped overboard through a series of burners – "spill duct ramjet burners"[4][16] which are arranged in a ring around the central core. These are fed air that bypasses the precooler."
Excess, as in, the excess amount of intaken air that can't be cooled by the burned hydrogen.

This seems to be part of the design and has always been. As Bill Gates would say, it's not a bug, but a feature.

Still, trying to know more about those "spill duct ramjet burners" and how they actually work would be interesting.

>>5309300
Wild and utterly uniformed thought...could they be crack the water that would otherwise be ice to generate additional oxygen?

>>5309300
The "spill duct ramjet burners" are still present in their most recent website design, tough. It's not something they wiped out.

>>5309274
>Elon Musk has been talking about turnaround time in the single-digit hours, which barely gives them time to run diagnostics, refuel, restack, and load the new payload.
Is that safe?

I know the shuttles could pass several days of entire check-up after they had landed. How can SpaceX bypass that?

>>5309360
>This seems to be part of the design and has always been.
Of course it's part of the design. Anyone with basic high school physics could figure out that the heat capacity of hydrogen is insufficient to provide the amount of cooling they're talking about.

But the point is, to feed their efficient rocket (or, let's be honest: jet), they need to process significantly more air than they use in it and burn some of their fuel in an inefficient ramjet.

>>5309360
Oops my bad.

excess of non-burned Hydrogen, indeed.

>>5309360
Here is the clean version of the image, in case anyone is interested.
Source:
http://www.reactionengines.co.uk/image_library.html

So when are we realistically going to send people to the moon? Mars?

>>5292113
Privatization rarely does any good.

Muh profit.

>>5309398
>Is that safe?
Hell no. But neither was the space shuttle.

They are planning on having a high initial rate of failure on reused stages.

Most missions will be unmanned. The first stage won't be doing re-entry. The second stage will never be manned on re-entry. The Dragon capsule will be capable of separation and safe landing at any stage of launch. So there's most of your risk to human life eliminated.

The launch system components come off an assembly line, so replacements are available and affordable. Each stage or booster will cost no more than $30 million, and each is intended to pay for itself on the first flight, so they can do a lot of replacements until they get it right.

When they do get all the bugs worked out of the system, after thousands of launches, it could be as safe for passengers as a commercial airline flight. Compared to the space shuttle, everything is far simpler. No tiled heat shield. No human crew. No hydrogen embrittlement. No refurbished solid rocket boosters. No crumbly foam external fuel tank with owls nesting in it. No wings. Far, far simpler rocket motors.

>>5309434
Hopefully to Mars within the next 100 years.

Maybe we need to put someone back on the moon again to spark interest again into the space program.

>>5309444
>When they do get all the bugs worked out of the system, after thousands of launches, it could be as safe for passengers as a commercial airline flight.
There was a French cartoon, called the Shadock, telling the story of a bunch of inept alien birds wanting to explore space.
They rocket where so shitty that they only had one chance out of 1000 to work, so they decided to make the 999 first rocket as fast and as shitty as possible so that they could build the 1000th as soon as possible and mount on it. This is strangely reminiscent.

>>5309274 >"even simply cooling the air needs more liquid hydrogen than can be burnt in the engine core."
>(there are references, but the Skylon people have since taken this information offline, and replaced it with "under construction" notices and stuff that's more vague)

If you watch the lecture above, or maybe the interview, he makes a statement along these lines but what's quoted is incomplete. He claims careful playing with thermodynamics allows for a much greater efficiency in the hydrogen required for cooling.

I'll try to find it before it completely forget.

>>5310334
>>5309274


http://www.youtube.com/watch?feature=player_detailpage&v=2G-HPHNrrLQ#t=817s

They can use heat from the hydrogen to drive a turbine

>>5310361

>If you get to grips with the thermodynamics and invoke entropy as well as conservation of energy then there are some interesting tricks that you can play.

>Perfect gas relationship for change of entropy of a fluid. Involving temperature ratio and pressure ratio

>Set delta entropy to zero

>Trade temperature ratio for pressure ratio.

>Use hydrogen not only as a coolant but as a heat rejection system lots of interesting things are possible.

i.e less hydrogen is required for cooling and waste heat is being used to drive the compressor. Hence more fuel efficiency

>>5310361
Of course. And you can see from their design, or from taking 10 minutes to do the very simple math with an elementary knowledge of thermodynamics, that they still obviously need more hydrogen to cool the air than they're going to burn with the air they cool.

Liquid hydrogen has just not got a high heat capacity. Incidentally, they need to supercool the liquid hydrogen, almost to the freezing point.

Skylon is an interesting idea, but it's not as good as it sounds. It's an absolute bare minimum of 10 years from the first orbital test flight, no matter who starts throwing wads of money at them, the efficiency gain from airbreathing engines is less than it's made out to be, it's not clear that the engines are even going to work, and it would be extremely easy for a small reinforcement here and there and additional maintenance requirements to turn it into a hangar queen with no payload capacity to speak of. That's if it doesn't just come apart mid-air and turn out to be the world's most expensive expendible rocket.

There are VERY good reasons not to do a reusable SSTO. You're lifting the whole vehicle to orbit, just to get the payload up, and the whole thing has to go through re-entry.

There are VERY good reasons not to do either horizontal launch or airbreathing engines (except in a rather slow-moving first stage, generally referred to as "air-launch"). You pass through a lot more thick lower atmosphere and suffer much more drag.

>>5310566
The bottom line is that the Skylon people are saying if you bring them dump trucks full of R&D money, and everything goes exactly according to plan, you might see spacelaunch at $1000/kg in 2025. And there's a good chance that you wouldn't see spacelaunch at all.

Whereas the SpaceX people are saying that as long as they keep getting contracts, you might see $1000/kg in 2015, and if that attracts enough new business, and everything goes exactly according to plan, there's a smooth slope all the way down past $25/kg. And they're already almost down to $3000/kg and saying they could do $2000/kg next year if they could find heavy launch customers, even if their plans for reusability don't work.

While an airbreathing, horizontal-takeoff SSTO spaceplane fueled by liquid hydrogen is intuitively appealing, it pays severe penalties for matching that description.

>>5310566
http://www.youtube.com/watch?feature=player_detailpage&v=2G-HPHNrrLQ#t=1878s

Just leaving this here. Back later.

>>5310613

http://www.youtube.com/watch?feature=player_detailpage&v=2G-HPHNrrLQ#t=2100s
>Even with these thermodynamic tricks the engine still takes in far more hydrogen than it needs
>That extra hydrogen is added to the burners in the bypass duct

>>5309300 >There has to be a bypass for much of the air that comes in the intake, if for no other reason than to carry the water rejected from the precooler.

The captured airflow does not match the engine air flow. The bypass duct corrects this.

>>5310639
Sorry, but "takes in" is confusing. The exact wording is more clear:
>Even with these clever thermodynamic tricks the engine still takes far more hydrogen than you need for combustion in the main chamber

>>5310652
>The captured airflow does not match the engine air flow. The bypass duct corrects this.
If this was the problem, the smarter way to handle it would be to capture less airflow, a thing normally done by moving that cone thing forward and having a smaller intake.

They have other reasons to bypass air: to sweep away the rejected moisture and to provide oxygen for the ramjet portion, which is actually where most of the fuel (about two thirds) is going to be burned before the switch to rocket mode.

Skylon (2025 ?)
>payload - 15 tons
>fuel mass - 277 tons
>service life - 200 missions
>turnaround - 2 days
>unit cost - $650 million
>launch cost - $1000/kg

Falcon 9 1.1 (2013)
>payload - 13 tons
>fuel mass - ~450 tons
>service life - 1 mission
>turnaround - N/A
>unit price - $54 million
>launch cost - ~ $3400/kg

Falcon Heavy -- reusable variant (2015 ?)
>payload - ~30 tons
>fuel mass - ~1300 tons
>service life - ???
>turnaround - "single-digit hours"
>unit price - $100-150 million ?
>launch cost - from $4000/kg (total reuse failure) to $25/kg (total reuse success)

Note that although the fuel mass of the Skylon is lower, there would be no savings on fuel. A much lower fraction of that mass would be liquid oxygen, which is pretty much always going to be the cheapest component, and the rest will be liquid hydrogen, which carries about three times as much energy per unit mass as kerosene does, and has a more-than-proportionately higher price. And SpaceX is switching from high-grade RP-1 kerosene to the much-cheaper liquid methane.

>>5303385
>This is revolutionary if it works, I'm not sure you can possibly question that.
It's already been established ITT that, even if they DO somehow achieve they're projected figures, it's STILL inferior to conventional rockets due to the sheer weight.

However, the SST application might have some promise.

>>5310566
How about a reusable 2STO? Or an expendable SSTO?

>>5310942
The SpaceX plan is a reusable 2STO, and it looks pretty good to me. I think a 2STO or even 3STO (jet takeoff to launch zone, ramjet boost to high-altitude supersonic, rocket shot to orbit -- all three land separately) spaceplane would be alright, if you don't want to rely on vertical landings, but SSTO imposes some really severe constraints.

An expendible SSTO would start to make sense once you had a recycling plant in space. It's not a bad way to move fuel tanks and rocket motors to LEO, if you've got something to do with them there.

Even so, it would work a lot better if launched at mach 3 in the upper stratosphere. A flyhome reusable first stage just makes so much sense, even if it only makes a modest contribution to speed. You can optimize your rocket for low-to-no pressure, and it doesn't have to fight air resistance for long.

If the SpaceX second-stage re-entry plan doesn't work, I hope they'll stockpile them in orbit rather than send them down to be burned up. That's probably a ton of lithium-aluminum and a good vacuum-optimized niobium rocket nozzle. Someone will find a use for those on a trip to Mars or the moon.

>>5292238
>After two weeks we are doing flyby next to Planetary Resources heavy transport ship with size of twin towers
>and all of a sudden, two space ships crash right into them.
>It was the 29th anniversary of 9/11
>They did it for the lulz.

>>5310655
I consider the most interesting part is what he say right afterward afterward, that's it, that the spill duct ramjet burners are mostly used during Mach 3 to mach 3.5 (the moment the engine is the less efficient and Hydrogene is used the most to cool down the intaken air), but one it reach mach 5, it's almost completly efficient and almost none of the intaken air is bypassed.

He do not precise if there is still an excess of hydrogen being rejected, there.

>>5310889
>A much lower fraction of that mass would be liquid oxygen
Sorry, I got this wrong.

The Falcon 9 1.1 carries about 150 tons kerosene to 300 tons oxygen, while the Skylon would carry 66 tons hydrogen to 150 tons oxygen.

To put it in perspective, if the Falcon 9 1.1 ran on hydrogen, it would probably take in the neighborhood of 40 tons hydrogen and 320 tons of oxygen, due to the superior performance of hydrogen.

>>5311037
>one it reach mach 5, it's almost completly efficient and almost none of the intaken air is bypassed.
>He do not precise if there is still an excess of hydrogen being rejected, there.
There would have to be a larger excess of hydrogen, because the air would be hotter. Most would probably not combust in the ramjet burners, but burn uselessly in the air behind.

However, there would still be a propellant mass advantage as long as less than 8 times as much hydrogen was used to cool the air as was combusted in the main chamber.

>>5310994
>That's probably a ton of lithium-aluminum and a good vacuum-optimized niobium rocket nozzle. Someone will find a use for those on a trip to Mars or the moon.
Come to think of it, most of that mass could be converted to propellant.

All you'd need is a way to powder it, and you could mix it with liquid oxygen or water about 1:1, and the aluminum-lithium-oxygen slurry would make pretty decent rocket fuel.

>>5293297
FUCK YES!

>>5310683 >If this was the problem, the smarter way to handle it would be to capture less airflow, a thing normally done by moving that cone thing forward and having a smaller intake.

The air captured isn't useless, it's just not optimal for the main engine. Perfect for the excess hydrogen from the cooling system.

Do you have a reference about the moisture? It sounds like an interesting idea but I can't remember seeing it mentioned anywhere.

>>5310942 How about a reusable 2STO? Or an expendable SSTO?

An expendable SSTO makes no sense.

If it's expendable there's no reason to not make use of the chance to shed a lot of weight. Automatic fuel consumption reduction.

Even with advanced engines if you have this opportunity there's no real choice but to take it.

>>5311389
Kind of noob, there, but what does 2STO and SSTO stand for?

>>5311410

Two stage to orbit and Single stage to orbit.

>>5311488
Thanks.

I'm excited about spacex

However there is something I do not understand.

Elon Musk seems rather dismissive of Reaction Engine's technique for lowering the quantity of fuel you need to put into orbit (I recently watched the Astronomical Royal society video on youtube he was at a couple of days/weeks ago, and it came up). Their idea was to have a rocket engine capable of using oxygen as it goes up, only switching to its oxygen supply once there's no 'free' oxygen to be had. This seems like a sound principal, every gram counts after all, and Elon Musk is all about lowering the amount of stuff you need to carry up there.

Any explanation?

>>5307873
oh! I guess your jealousy can go full throttle
>>5293129
>>5293174

>>5311562

>Elon Musk is all about lowering the amount of stuff you need to carry up there.

He is not, he is about reusability and low costs. Fuel is cheap and there is no reason to seek lower mass at all costs.

>>5311580

Obviously I meant lowering the amount of stuff that isn't payload.

Jesus.

>>5311562
We just have got a long discution about Skylon, in case you didn't notice.

But, I consider kind of normal that Musk will mostly focus on his own project and won't try to divert attention to concurrency. It's fair business practice, after all.

>>5311581

Thats what I meant. Reusable Falcon 9 will have lower payload mass and higher structural/fuel mass than non-reusable versions. Still, it will likely be much cheaper.

>>5311585

I forgot the name of their project, so yeah I didn't notice.

Not drawing attention to potential competition makes sense from a business perspective, but is disappointing from a sci/eng point of view. The best ideas often wind up being combinations of several other ideas, not just 1 big one devised completely on its own. Intellectual property theft FTW.

In any case I think there's nowhere near enough capital going into research for this kind of stuff, whether it's spacex or reaction engines. It's pitiful.

>>5311592

Aha, gotcha.

Pic related to topic. Turns out it wasn't a joke after all.

>>5310942
Yeah, Atlas was an interesting design. Ditch two of your engines but keep the tankage. They only got away with it because they used really thin balloon tanks, so there wasn't much dry weight penalty. Unfortunately, that kind of tank was hard to transport and handle unless you kept it pressurized, and it doesn't scale up well. The last to use this architecture, the Atlas II, could only take 7 tons to orbit.

(Trivia: WD-40 was developed to keep ocean spray from sticking to Atlas tanks before they were launched from Vandenberg. It stands for "Water Displacement formula #40")

>>5311597

I enjoyed Black Books, but that was a while ago.

Point stands, for every decent BBC TV serial I can think of like 10 ones from the US.

Sure with competition you get a lot of drek, but you get real gems too.

>>5311562
http://www.youtube.com/watch?v=wB3R5Xk2gTY

Elon Musk lecture at the Royal Aeronautical Society

>>5311766

Elon says full re-usability is still another 5-6 years away, I'm not sure I like the sound of that. They have a lot of new technology to think of and develop in that time. I can see they've been successful in making an assembly line for already existing technology but I'm not recognizing any major advancements on their part. I can see them hitting a roadblock they haven't predicted along the way to full re-usability.

The Reaction Engines Sabre / Skylon design looks much more mature and complete. They can talk you through every single nitty gritty step of the design about how it will work and how it can be manufactured. I think they will be spending their time on getting infrastructure to build the Sabre engines and help other companies get started manufacturing of the Skylon itself.

>>5312055
You have to understand that "full reusability" means the second stage and the Dragon capsule also being fully reusable.

Dragon capsule reusability is a special challenge because that's a vehicle for humans. They have to run a lot of test flights before used capsules can be rated for human passengers.

The goal of second-stage reusability has a lot of people scratching their heads. The second stage has to go through re-entry, and it's quite a large object. On top of that, it only has one rocket motor on it, and a much smaller tank. It's a much greater challenge to recover for a much smaller savings than first-stage reusability.

First-stage (and booster) reusability is what makes the most sense, and they might begin testing next year, and do actual work with it the year after that. The first stage is by far the most expensive part, and reusing it would cut launch costs at least in half.

For a Falcon Heavy type of design, probably about 90% of vehicle cost would be in the first stage. Just making the first stage reusable could be enough to achieve $100/lb launch costs.

>>5310994
>If the SpaceX second-stage re-entry plan doesn't work, I hope they'll stockpile them in orbit rather than send them down to be burned up. That's probably a ton of lithium-aluminum and a good vacuum-optimized niobium rocket nozzle. Someone will find a use for those on a trip to Mars or the moon.
There's a thought.

You know, NASA had plans to drag Shuttle ETs into orbit (since they were already 97% of the way there at jettison) to build a massive wet-workshop space station with. They axed the plans after the Challenger disaster.

>>5311389
>If it's expendable there's no reason to not make use of the chance to shed a lot of weight. Automatic fuel consumption reduction.
Not necessarily true. With Atlas, Convair looked at the possibility of splitting it in two to make a true two-stage rocket, and concluded that the weight of the staging hardware would cost them more performance than just dragging that lightweight balloon tank all the way to orbit.

Eventually they wound up going in the OPPOSITE direction with Atlas H (seen in [>>5310942]), actually STRETCHING their 1.5th stage considerably.
>>5311605
>Doesn't scale up well
Why do you say that? Just because they haven't built a large balloon tank doesn't mean it's unfeasible.