Which one in the end will allow us to get more tonnage into LEO for the lowest cost?
Well what about what Virgin Galactic's approach but scaled to way bigger, I mean huge, I mean a much bigger carrier plane and spaceplane, could this ever beat rockets?
Wings are silly in space. Rockets provably can land like they always were meant to - on a pillar of flame, tail first. Hence, spaceplanes are pretty silly.
Which one in the end will allow us to get more tonnage into LEO for the lowest cost? Which one can scale bigger than the other? I'm assuming rockets can scale bigger than a spaceplanes can (since Elon stated that eventually they'll have a rocket that'll dwarf even the ITS).
My defenition for a spaceplane (what is yours?) is jet engine and wings.
Assuming reusability can reduce the cost of luanch to ~the price of fuel+refurbishment, spaceplanes may set a lower price due to:less fuel needed with the much higher ISP of jet engines andless refurbishment needed due to more lofted entry.
Quote from: dror on 06/02/2017 12:30 pmMy defenition for a spaceplane (what is yours?) is jet engine and wings.Topic is spaceplane, not airlaunch, so jet engine is not enough.Quote from: dror on 06/02/2017 12:30 pmAssuming reusability can reduce the cost of luanch to ~the price of fuel+refurbishment, spaceplanes may set a lower price due to:less fuel needed with the much higher ISP of jet engines andless refurbishment needed due to more lofted entry.Fuel price is insignificant.Regarding refurbishment, a spaceplane is always more complex than a rocket, so I don't you can just claim that refurbishment is cheaper.
Regarding refurbishment, a spaceplane is always more complex than a rocket, so I don't you can just claim that refurbishment is cheaper.
Both VTVL and HTOL rocket vehicles of (relatively) comparable performance have demonstrated low cost operations with turnaround times less than an hour
At this point I don't recall any rocket that has been recovered and re-used returning from an orbital velocity...
Quote from: Gliderflyer on 06/02/2017 11:54 pmBoth VTVL and HTOL rocket vehicles of (relatively) comparable performance have demonstrated low cost operations with turnaround times less than an hour I'm scratching my head to think what you're talking about? The only thing that comes to mind is the Rocket Relay League work that XCOR did but then I'm wondering what the VTOL you would be using for comparison is.
The difference between reusable rockets and spaceplanes is that we know a spaceplane can do the reentry.
Quote from: Rocket Science on 06/02/2017 01:17 pmAt this point I don't recall any rocket that has been recovered and re-used returning from an orbital velocity...True.In fact 3 designs with wings have demonstrated reentry from full orbital speed, with 2 (Shuttle and X37b) managing repeated reentries. The difference between reusable rockets and spaceplanes is that we know a spaceplane can do the reentry.The concepts of Philip Bono in the 60's did not think a conventional rocket aspect ratio could be landed, hence the shorter, wider style of his designs. We now know that, at least for the booster a LV wth this AR can be landed. We are hoping that SX will manage to find a way to make their upper stage recoverable on the FH but the truth is Musk has given up on doing this once before, so we'll have to see. The big difference is that with rockets you hope for full reusability but with spaceplanes you already known it can be done, the problem is in the engines since no one has ever designed a plane with a structure that's less than 10% of fuel weight. OTOH they have designed planes with structures < 26% of fuel, which is viable with something like SABRE.
Quote from: john smith 19 on 06/03/2017 02:19 pmThe difference between reusable rockets and spaceplanes is that we know a spaceplane can do the reentry.We know that VTVL has a good chance of working for first stages. We know that space planes work for reentry. The next step seems obvious.
Quote from: john smith 19 on 06/03/2017 02:19 pmThe difference between reusable rockets and spaceplanes is that we know a spaceplane can do the reentry.We know that VTVL has a good chance of working for first stages. We know that space planes work for reentry. The next step seems obvious. - Ed Kyle
Wrong, other structures can reenter
Quote from: edkyle99 on 06/03/2017 03:20 pmQuote from: john smith 19 on 06/03/2017 02:19 pmThe difference between reusable rockets and spaceplanes is that we know a spaceplane can do the reentry.We know that VTVL has a good chance of working for first stages. We know that space planes work for reentry. The next step seems obvious. - Ed KyleTurn the first stage into a spaceplane!
Spaceplanes can be very interesting. For example, the re-entry regime is much tamer for both cargo and crew. Another example is the ability to take something from orbit (a satellite for example) into your hold and bring it back to Earth. The rocket equation is pretty mean to SSTOs though. A two stage LV using a spaceplane (say, a re-usable booster with a re-usable spaceplane mounted to it) may in the future be(come) a good competitor to re-usable rocket launch.
Which structures did you have in mind that a)Reached orbital velocity and b) Can be reused afterward?
Quote from: Jim on 06/03/2017 07:43 pmWrong, other structures can reenterContext James, context. And in this context the key words are "reusable," "orbital" and "velocity."Which structures did you have in mind that a)Reached orbital velocity and b) Can be reused afterward?
Quote from: john smith 19 on 06/04/2017 06:25 amQuote from: Jim on 06/03/2017 07:43 pmWrong, other structures can reenterContext James, context. And in this context the key words are "reusable," "orbital" and "velocity."Which structures did you have in mind that a)Reached orbital velocity and b) Can be reused afterward? Any of the Apollo, Gemini or Dragon capsules.
Considering what happened to Columbia, I'm not sure why you're advocating for wings. "It's always been done that way" is rarely a good argument, especially if it's only ever been done once. Twice if you want to count the X-37, but Gemini 2 did that first.
and you forgot Buran.
I meant to include airlaunch as well when I made this thread. So airlaunch where the carrier plane carries a spaceplane or where the carrier plane carries a booster. Say you take the stratolaunch plane and take the second stage off the ITS and put them together, would that be superior to the ITS as a whole? I mean I just sit here and day dream about the future of spaceflight and we have all these new people on the scene with all their schemes but I keep wondering which one in the end will be the superior way of doing things. I think at this point Elon And Jeff have the right idea with VT/VL rockets but at the same time I dont want to shut the door prematurely on other ideas as well. Say you were given a 100 billion dollars to revolutionize spaceflight so that one day the average man might be able to book a flight into space. Which route would you take? Would you go down the path Elon and Jeff are taking?
Quote from: Clueless Idiot on 06/07/2017 07:58 pm I meant to include airlaunch as well when I made this thread. So airlaunch where the carrier plane carries a spaceplane or where the carrier plane carries a booster. Say you take the stratolaunch plane and take the second stage off the ITS and put them together, would that be superior to the ITS as a whole? I mean I just sit here and day dream about the future of spaceflight and we have all these new people on the scene with all their schemes but I keep wondering which one in the end will be the superior way of doing things. I think at this point Elon And Jeff have the right idea with VT/VL rockets but at the same time I dont want to shut the door prematurely on other ideas as well. Say you were given a 100 billion dollars to revolutionize spaceflight so that one day the average man might be able to book a flight into space. Which route would you take? Would you go down the path Elon and Jeff are taking?ITS won't fit. It's supposed to be about 12 meters in diameter. That's roughly the distance between the two bodies on the Stratolaunch, but the ground clearance for the payload is about 1/4th that. That aside, air-launch doesn't give you much of a benefit, yes, you save roughly 10% of the fuel it takes to get to the launch altitude, but really it's simpler to just make the first stage ~10% bigger. The major pluses are you do avoid the costs of having to build or lease a launch site and maintain it, and you have more control over when you can launch.
"But yes, Stratolaunch would have to be TEN TIMES bigger to lift the ITS upper stage." Lol well that's not practical at all so I guess for the foreseeable future reusable rockets really are the future eh? So Elon and Jeff chose the right route to take it seems
Fella's I think the verdict is out on this one, reusable rockets will give you the best bang for your buck,
Quote from: edkyle99 on 06/03/2017 03:20 pmQuote from: john smith 19 on 06/03/2017 02:19 pmThe difference between reusable rockets and spaceplanes is that we know a spaceplane can do the reentry.We know that VTVL has a good chance of working for first stages. We know that space planes work for reentry. The next step seems obvious. - Ed KyleVTVL 1st stage + spaceplane upper stage?
Quote from: Barrie on 06/03/2017 10:17 pmQuote from: edkyle99 on 06/03/2017 03:20 pmQuote from: john smith 19 on 06/03/2017 02:19 pmThe difference between reusable rockets and spaceplanes is that we know a spaceplane can do the reentry.We know that VTVL has a good chance of working for first stages. We know that space planes work for reentry. The next step seems obvious. - Ed KyleVTVL 1st stage + spaceplane upper stage?Something along those lines. The upper stage would need to reenter at much higher velocity than the first stage. The winged reentry method (STS, Buran, X-37B, etc.) is proven. The problem is that this limits the upper stage to LEO. - Ed Kyle
I've never ceased to be boggled at the concept of VTHL. You need a vehicle that's strong in two major axes and big enough to carry all the propellant.
LEO isn't a problem if it can hand off the payload to a cislunar tug. That will cover everything except the occasional interplanetary mission.
Yes, and that applies to both VTHL and HTHL. (The latter is actually worse, since it needs to sit on the tarmac and lift off fully loaded, whereas VTHL spaceplanes only need to support its near-empty weight while horizontal)
Quote from: RonM on 06/09/2017 03:27 pmLEO isn't a problem if it can hand off the payload to a cislunar tug. That will cover everything except the occasional interplanetary mission.I think in the future this will eventually prove to be the most cost effective solution as this makes full reusability a lot easier.Kinda like how things were in the Space Odyssey movies.
If lunar or asteriod supplied fuel to LEO ever becomes cheap enough it could partially refuel a SSTO for earth return. A SSTO becomes lot simplier and lighter if it has amble fuel for retropulsive burn and landing.Water or cryo fuel can also be used for cooling of heat shield surfaces.