Space Planes

[gaetanomarano]

"...they want to have a backup plan in the case of a contingency..."<br /><br />then, for 30+ years (before the Soyuz-backup era) was run by idiots... no, of course<br /><br />now NASA can use the Soyuz-backup thanks to russian democratic evolution, but this wasn't planned<br /><br />NASA flights (expecially Apollo) NEVER had a "plan B"!<br /><br />CEV-LEM2 missions appear the same of Apollo: NO BACKUP<br />

 

[propforce]

<blockquote><font class="small">In reply to:</font><hr /><p>So I'm in a goofy mood today. I have tomorrow off work and am going to the Science Museum, so hopefully you can excuse a little levity on my part. <p><hr /></p></p></blockquote><br /><br />Okay... dudette <img src="/images/icons/smile.gif" /><br /><br />How's Ada doing? It's been a while since her last status update, no?<br /><br /> <div class="Discussion_UserSignature"> </div>

 

[vt_hokie]

Ah, the L-1011...that was a better aircraft than it was given credit for. It's a shame you don't really see them anymore, while the inferior DC-10's and MD-11's continue on...

 

[wdobner]

<i>Why don't you contact George Lucas? I hear he's good at building SSTO space planes? </i><br /><br />Why do you dismiss this out of hand? What proof do you have of an SSTO not being possible? Clearly there are more than a few folks with more letters after their name than I'm willing to bet either of us have who seem to think that not only is an SSTO possible, a HOTOL SSTO is possible. Keep in mind we haven't built one, and our efforts to date have been half-assed to say the least, so there's not a whole heck of a lot of evidence either way. Technical challenges can always be surmounted with a proper R&D program. We had to surmount plenty of technical issues to get to the moon and even to achieve LEO. All you're saying by moaning on and on about how hard it will be to build an SSTO is that you clearly think the technologically pioneering spirit which gave us Mercury, Gemini, Apollo, and even the Space Shuttle has left us and all we can do is adapt 20-30 year old technology to do the same thing we did 30 years ago. Exploration isn't just some simpleminded pursuit of going to the next celestial body. That may be the most exciting side of things, but technological innovation has been a hallmark of NASA's space program since the very beginning. It's highly disappointing to see NASA shrink from the technological forefront at this point. Even though the shuttle may have been a bit of a failure operationally it advanced the science of creating robust ceramics by leaps and bounds. Further NASA programs, in partnerships with various universities, have further advanced the state of the art in ceramics manufacturing, to the point where we are now looking at a machinable, thermal shock resistant ceramic which behaves like a metal. Imagine a nut and bolt which can go in a 500 degree oven for 3 minutes, then be handled by unprotected human hands, loosened and tightened, AND can be immersed in water without shattering. I know I sound like Ron Popeil and this is onl

 

[dobbins]

It's hard to get to space, why make it harder by hauling a bunch of stuff up that you don't need when you get there?<br /><br />

 

[nacnud]

<font color="yellow">What proof do you have of an SSTO not being possible?<br /><br /><font color="white">Because there isn't one yet? OK thats a crass answer but if you do get a SSTO working with available technology then a TSTO would beat it for payload or cost. <br /><br />Unfortunatly I don't think there is a magic bullet on this one.</font></font>

 

[barrykirk]

I don't believe the starship Enterprise had any wings. And it certainly was a futuristic concept. It could do things far beyond the capabilities of anything we have now.<br /><br />Also the shuttlecraft carried by her didn't have wings either.

 

[dobbins]

Bingo! TSTO is more logical than SSTO and a far better investment.<br /><br />

 

[barrykirk]

So your saying that the heatshields and parachutes are so lightweight that their isn't much penalty for taking them to the moon and back.<br /><br />For that you get an anytime abort to earth "safety" capability for real cheap. Wow, the capsule is looking better.<br /><br />That anytime abort capability would be awefully expensive for a winged vehicle.<br /><br />I'm assuming that you don't drag the chutes and heat shield from Low Lunar Orbit to the Lunar surface and back. Is that correct?

 

[nacnud]

Yes, the heat shields developed for the shuttle, although fragile, are comparatively lightweight, as are parachutes. There are also more modern materials such as SIRCA.<br /><br />Yes hence the Luna orbit rendezvous where the CEV stays in orbit around the moon while a separate landed travels to the surface and back.

 

[vt_hokie]

<i>Bingo! TSTO is more logical than SSTO and a far better investment. </i><br /><br />I don't disagree with that. Perhaps that will change if we can manage to get a scramjet powered lifting body all the way up to orbital velocity, but for now, how about something like this?<br /><br />http://www.astronautix.com/craft/spiralos.htm<br /><br />Or this?<br /><br />http://www.astronautix.com/craft/liiplane.htm

 

[nacnud]

Well both of those are three stage to orbit vechicles or two stage plus droptanks, this migh be easier, maybe.

 

[barrykirk]

Where do I start?<br /><br />How does the thrust to weight ratio of a ram or scramjet compare to?<br /><br />a) Turbofan<br />b) Turbojet<br />c) rocket<br /><br />Let me explain where I'm going.<br /><br />I started a thread a few weeks back on the possibility of using a subsonic jet engine as a first stage or zero stage of a VTOL to take advantage of the extremely high ISP of jet engines in the lower atmosphere and to start the rocket stages above the thickest parts of the atmosphere. This would reduce max q since it would happen at high altitudes where there is less air.<br /><br />People here pointed out that the thrust to weight ratio of rocket engines far exceeds that of jet engines. In fact the best thrust to weight ratio for a jet engine comes from a turbofan style and even than, it would take one of the largest turbofans ever built to lift a Falcon 1 rocket off the pad.<br /><br />Now I understand that jet engines have much higher ISP than rockets which is a reason people want to use them for efficiency. I also understand that deriving a large portion of your lift from wings in a horizontal takeoff configuration can reduce the thrust requirements.<br /><br />If the thrust to weight ratio of a scramjet/ramjet is miniscule compared to a rocket than we may have a problem.<br /><br />Such a vehicle would have a very low acceleration in the upper atmosphere. So it would take a long time accelerating a large mass to high speeds. But since it would spend a large amount of time in the atmosphere at very high velocities wouldn't it lose a tremendous amount of energy to drag?<br /><br />The point i'm trying to make is that a gain in efficiency in one area, namely the higher ISP of a jet engine in a large region of the launch might be lost by a tremendous loss due to air drag.<br /><br />I don't know how these things balance, but I'm just throwing this one out there. Does anybody know the numbers?

 

[scottb50]

Spirol would be pushing technology now, let alone 30 years ago. Sounds awfully complicated to me.<br /><br />The quickest and safest way to orbit can easily be built today using Shuttle proven assets, facilities and personnel. 0/0 zero escape provisions for people or cargo. <br /><br />Four autonomous SSME's, two hybrid solid motors, with Shuttle steerable nozzles, and two high bypass turbofan engines power the first stage. The Second stage has two RL-60, re-startable engines and stability thrusters for autonomous operation. Payloads attach to the Second Stage, which becomes a Tug when it reaches Space.<br /><br />Payloads are carried in standard containers or fairings are used to enclose any number of payloads.<br /><br />Using the same two structural pieces throughout the system also makes it super cheap, repeatable and multi-taskable. The same design can be built the size of a pen, for lap-top computer fuel cells, or other storage accumulators of various sizes. They can also be used as cargo containers, propellant tanks or as Stations, Tugs, Cyclers, Landers and surface facilities on the moon and Mars, or Antarctic or anywhere else. <br /><br />Basically it's pretty simple, two identical Segments are locked together, over single piece fiber-wound tubes to form Modules, the ends are identical so they can dock to any other Module. The Segments have identical ends and a central reinforcement structure that carries adapters allowing Modules to dock side by side with any other adapters, of that size.<br /><br /> <div class="Discussion_UserSignature"> </div>

 

[vt_hokie]

<i>Spirol would be pushing technology now, let alone 30 years ago. Sounds awfully complicated to me.</i><br /><br />I don't mean to turn this into a conspiracy thread, but what do you think about the likelihood of an aircraft like this one existing?<br /><br />http://www.abovetopsecret.com/pages/svalk.html <br /><br />fwiw, I don't think such a vehicle exists. I think they've got something - perhaps an aircraft that flies in the Mach 6 range - but certainly not a "mini space shuttle". It is interesting, though, that there have been supposed sightings of this XB-70 sized aircraft in addition to the smaller, presumably hypersonic vehicle.<br /><br />

 

[krrr]

Interestingly, the Russians aren't giving up on the spaceplane. Latest iteration is called MRKS. Roskosmos' budget for 2006-2015 has more than 9 billion roubles allocated to it.<br /><br />The MRKS system consists of a large flyback booster and an (initially) expendable upper stage. It is supposed to carry 25 to 35 tonnes into LEO.<br /><br />One concept I have seen uses six 200-tonne LOX-Methane engines for the reusable booster and LOX-LH2 for the upper stage. They are also talking about using two boosters in tandem for 70 tonnes to LEO.<br /><br />Development is to begin in 2009.<br /><br />This thread from the Novosti Kosmonavtiki forum has some information.<br />

 

[dobbins]

The Russians aren't in the position of betting their manned program on a space plane. If Klipper turns out like just about every other effort to develop a space plane, then they will still have the Soyuz.<br /><br />We are not in that position, we need something that the Russians already have a system that works.<br /><br />We have allready had one long grounding of the American manned space program due to developing a space plane. We have already gotten stuck with a space plane who's service costs were higher than an expendable capsule. We have already had a long series of paper space planes that never carried anyone into space. Enough is enough.<br /><br />I want something that works. I don't care if it looks like a Model T Ford, gets shot out of Jules Verne's Moon cannon, and splashes down in a giant vat of Jello, as long as the darn thing actually works.<br /><br />

 

[vt_hokie]

It may work, but it will do nothing to open up access to space. It will carry a few select astronauts a couple of times per year - fewer than the space shuttle - at a cost of billions of dollars. And the sole justification for using this expensive, antiquated system is so that 4 people can go back to the lunar surface for a week in 15 years. Sorry, but that doesn't excite me very much. In fact, I find it rather pathetic, considering where we should be by now!

 

[spacefire]

ya'all are probably wondering why I didn't join in...well I was away on a business trip. I'll check back on this post tomorrow at work when will have more time to waste <img src="/images/icons/wink.gif" /><br /><br /><br />Lifting bodies are THE answer, just so you know. <div class="Discussion_UserSignature"> <p>http://asteroid-invasion.blogspot.com</p><p>http://www.solvengineer.com/asteroid-invasion.html </p><p> </p> </div>

 

[henryhallam]

<font color="yellow"><br />The CEV is designed to fly unmanned. The CEV that takes the Mars crew to LEO will not wait for them for 2 years, it will return to Earth. The CEV to take the crew back to Earth would be launched later.<br /></font><br /><br />How do the Mars crew brake into LEO on their return for transfer to the CEV? If by aerobraking, why not go all the way to the surface? If by an enormous rocket, why not replace that mass with a direct-entry heatshield?

 

[vt_hokie]

Or why not just use this instead! <img src="/images/icons/wink.gif" /><br /><br />http://www.mufor.org/lazar.htm<br /><br />(tic)