Space Planes

[nacnud]

<font color="yellow">Why take the Earth entry vehicle to Mars and back?<br /><br /><font color="white">So you can use direct aerocapture from Mars. You'll loose the Mars vehicle though, I don't know whether the fuel saving is worth it either, any ideas?</font></font>

 

[radarredux]

> <i><font color="yellow">I am hearing that the CEV for a Mars mission will bewaiting in Leo or at a "L" site. Why take the Earth entry vehicle to Mars and back?</font>/i><br /><br />It sounds like there will not be an abort directly back to Earth from Mars as there will be for the Moon.<br /><br />The following is a silly and somewhat irrelevant question, but what I am thinking is: If the Mars mission will require a LEO docking and crew transfer before finally returning to Earth's surface, why not follow the same plan for the Lunar mission? This would provide a mission architecture more similar to t/Space than Apollo.<br /><br />If I was going to take a stab at answering my own question it would be: The abort to Earth option for the Lunar mission is more important because at this early stage we will prefer the extra level of safety AND the cost of moving the CEV back and forth to the Moon is a lot less than the cost of moving it back and forth to Mars.</i>

 

[darkenfast]

I have noticed in this and other threads a recurring proposal: a deep-space vehicle that will stay in orbit and be re-used (in this thread, the point was that it would be met by a space-plane). There are two big real-world problems with this. First, how do you slow down into low earth orbit from the inter-planetary or lunar return trajectory? Aero-braking is rough on a craft optimized for vacuum only, and carrying the fuel to and from the Moon or back from Mars (assuming in-situ manufacturing) is not exactly a good idea. Second (and to me the no-brainer), is: who is going to service and maintain this spacecraft in orbit? Look at what it takes to turn around the shuttle: a small army working for months! Take a look at the planning and preparation that goes into a spacewalk in the real world and then explain to us how a handfull of astronauts are going to refurbish and refuel a spacecraft for another deep-space mission. <br /><br />Someday I believe we will have the technology to go up in some sort of SSTO vehicle to a large space base, transfer to a nuclear-powered DSV and head for wherever. But now (and for the next few decades) we do NOT have that technology. It is in the realm of science fiction. However disappointing it is to some of the space cadets and trolls on this forum, it is not what we have in the cards now. Yes, we should continue research into new technologies, but not at the cost of cancelling all American manned spaceflight for many years (with the exception of the occasional bought seat on a Soyuz). Because that is what it boils down to. You can point to a dozen "Blank, Inc." wonderful proposals that promise miracle reductions in cost, but none of those companies has a chance in hell of changing the laws of physics, materials science, or safety considerations that make manned spaceflight so difficult.<br /><br />I don't care if the CEV looks like a flying can-opener, as long as it works, has a chance of being funded, and can go somewhere

 

[frodo1008]

How about a simple dose of reality here. This is the best of the future of NASA!<br /><br />The shuttle will fly for some 19 more flights in the next five years (2006 to the end of 2010), it will be used to finish as much as possible the placing of the rest of the already completed ISS components on the ISS itself. Sorry, anti-shuttle and anti-ISS people, but the reality is that is the way it is going to be. Any less than this and NASA's budget will take such a hit as to become basically non existant!<br /><br />In the time same time frame (if NASA is allowed to keep its current budget plus inflation) there will be enough money to finish the design and begin production on the capsule VSE. The VSE will have its first flight (barring show stoppers, and as Mike Griffin and NASA have chosen not only the least expensive option, but also the most produceable option then this may not eliminate all such show stoppers, but it does minimise them. Flights to LEO of the VSE on top of the five segment SRB should begin by 2007, and the design of the SHLV should be complete by the same time, and I would expect the first flight of the SHLV to begin by 2010. In the meantime, unmanned probes will also be continually sent to both the moon and Mars. <br /><br />I would hope to see the first flight to the moon by 2016 and the first landing by 2018. This IS NASA's current plan, and arguing over it is absolutely useless!! <br /><br />Quite frankly, I am not sure that I like all of this myself, but I am restrained enough to realize that there are those within NASA that do have more knowledge of these matters than myself. Also, the logic of using a tried and true method that is far less expensive than doing far more research into newer designs is simply inescapable. <br /><br />So let us go back to the moon in this time frame , and then work on building a far better space infrastructure between the moon and the Earth. This is going to take time, but at least it is possible with this kind o

 

[vt_hokie]

<i>The shuttle will fly for some 19 more flights in the next five years (2006 to the end of 2010), it will be used to finish as much as possible the placing of the rest of the already completed ISS components on the ISS itself. Sorry, anti-shuttle and anti-ISS people, but the reality is that is the way it is going to be.</i><br /><br />Let's hope so! I think we all know, however, that any significant problems, even if not catastrophic, could mean sudden death for the shuttle program. <br /><br /><i>Quite frankly, I am not sure that I like all of this myself, but I am restrained enough to realize that there are those within NASA that do have more knowledge of these matters than myself.</i><br /><br />Apparently the very intelligent engineers at Lockheed Martin felt that a lifting body design was a better way to go, but NASA shot them down and forced the capsule design.<br /><br />http://www.popularmechanics.com/science/space/1534782.html <br /><br />Also, the pure lifting body version of Russia's Kliper is indeed being designed for future applications beyond LEO (i.e. lunar missions).

 

[wdobner]

I have to say I agree DarkenFast. As much as the HOTOL SSTO RLV to specialized DSV appeals to me, it is alas a pipedream, a result of one too many Arthur C. Clarke novels. I readily acknowledge that at the moment the best we're going to get from NASA for a manned spacecraft is CEV and friends. Lets go back to the moon and hopefully do so in an economically efficient way such that money is left over for Mars and such. However, eventually we're going to reach the point where CEV will be more of a hinderance than a help and we'll need a dedicated deep space vehicle supplied by a vehicle capable of performing many cycles between the surface and LEO per year. It'll cost money to build of course, but in the long run the payoff would be more than worth it.<br /><br />The rub of course lies in the fact that NASA has drawn the X-43 and Prometheus programs down so much that I could swear they don't have a plan for getting anywhere in the solar system beyond the moon. Both projects are potentially useful to the long term inhabitation and exploration of space. However, both are recieving a starvation diet budget since the VSE was announced. Why does our little trip to the moon suddenly mean drastically reduced funding for other, potentially more important research projects? Are three guys standing on the moon collecting rocks and taking pictures really more important than the long term inhabitation of space in this half of the 21st century?

 

[josh_simonson]

Nasa is constructing a test facility for air breathing engines up to mach 20, meanwhile the military is working on hypersonic missiles. The X-43 program was a tremendous success as well, it seems to me that the whole scramjet concept is being quite adequately supported at the moment. However, it is silly to demand one when there is still basic research going on regarding how to go about simply getting one to work reliably at suborbital speeds (they're batting 50% success right now), let alone fly at orbital velocities. There was a long time between the first liquid fueled rocket and the first orbital flight. We can expect a similar development delay with scramjets. In the meantime, we need to go to space somehow, and it might as well be something cheap and easy for the interim. <br /><br />I'd be much more concerned with a more complex and expensive system that could gobble up funding like a 'son of shuttle'. The VSE is made of so many little pieces, instead of one big monstrosity like the shuttle, that it can be upgraded incrementally in capability at reasonable policial and financial costs.

 

[vt_hokie]

<i>However, it is silly to demand one when there is still basic research going on regarding how to go about simply getting one to work reliably at suborbital speeds (they're batting 50% success right now), let alone fly at orbital velocities. There was a long time between the first liquid fueled rocket and the first orbital flight. We can expect a similar development delay with scramjets.</i><br /><br />While I'm unaware of any recent evidence, there were certainly the unexplained sonic booms from some classified aircraft being reported over southern California back in the early 1990's. So, what were they flying out of Groom Lake or wherever the thing was based? Could there already be a high speed aircraft that uses scramjet propulsion? <br /><br />And as an aside, have there been any recent (say, post 2000) sightings of "Aurora", as it's come to be known? It seems like there was a lot of speculation 10 to 15 years ago, but I haven't heard much lately.

 

[vt_hokie]

Well, I dug up this site with google. Of course, there's no way to know if any of these reports are credible, but they are more recent than what I've seen before.<br /><br />http://users2.ev1.net/~w8368/aurora.htm

 

[drwayne]

Keep in mind, many more engines were specified for multiple starts and firings - this was needed to support test firings of flight hardware.<br /><br />I have a quote around from Hnery Spencer, the gist of which is that any regeneratively cooled engine is potentially reusable.<br /><br /><img src="/images/icons/smile.gif" /><br /><br />Wayne <div class="Discussion_UserSignature"> <p>"1) Give no quarter; 2) Take no prisoners; 3) Sink everything."  Admiral Jackie Fisher</p> </div>

 

[dobbins]

The Scramjet technology is something that would be of more use to the military than to space flight. They would be useful for very fast weapon systems, but for the Sci-Fi's fan's beloved SSTO space plane you wind up with a need for one engine to get the thing up to the speed a Scramjet can operate at, then the Scramjet engine, then a third rocket engine since the Scramjet can't operate in space. Three engines would make for an absurdly complex space plane. Of course some of the Space Cadets have an affinity for unnecessary complexity, considering it to be more advanced.<br /><br />

 

[frodo1008]

Let us not completely disregard the scramjjet and NASP concepts even though at this time I fully support NASA's current shuttle, ISS, and VSE efforts. I also think (You know, it IS possible to take a reasonable support position for both space planes and the current capsule design, there really isn't anything stoping such a position) that the more distant future may very well belong to such "space planes". Once the area of hypersonic scramjet flight is researched to the level of possibility, then even the complexity of a multiple engined craft becomes a possibility, and then quite possibly even a certainty.<br /><br />The advantages of such HOTOL taking off from airports around the world and using conventional engines to get to the start area of the scramjet and such a craft then taking passengers anywhere on the Earth in at most a few hours will indeed be realized within some twenty years, about the same time frame as the first human beings on Mars! Then probably using a built in linear aerospike type of engine (such an engine would not need a very high thrust as the craft would already be flying at 10-15 mach on its scramjets at an altitude of 100,000 feet or more) thrust itself into LEO.<br /><br />I think that with a large enough craft, and enough flights it may be quite possible to bring the cost of placing a pound into LEO down to the $500 - $1,000 per pound level from the current $10,000+ per pound level. Thus kick starting such areas as true space tourism, and possibly even solar power stations!<br /><br />This would then suffice until a true space elevator to GEO further drives the per pound cost down below the $100 per pound to GEO level. At this point not only does complete exploration of the solar system become possible, but the exploitation of the solar systems almost limitless resources also becomes possible. This would then become the jumping off place for true space colonization.<br /><br />To me at least the time frame is as follows:<br /><br />Current

 

[dobbins]

You are old enough to remember 1950s Sci-Fi. SSTO rockets with huge fins that looked more or less like like V2s and which used VTOL. Now it's 50 years later and the giant fins on the V2 style rockets have turned into wings and VTOL has changed into HTOL. Other wise it's the same old 1950s Sci-fi, and I have no reason to think it won't still be Sci-fi in another 50 years.<br /><br />If NASA had tried to build these SSTO V2 clones in the 1960s it never would have reached orbit, let alone the Moon. The same would happen if we listen to the Sci-fi buffs of today and try to build their dream rockets.<br /><br />

 

[vt_hokie]

I'll settle for a fully reusable two stage system! <img src="/images/icons/wink.gif" />

 

[dobbins]

Reusability is a means to an end, not an end in itself. If the service costs of a RLV exceed the costs of an ELV then building a RLV doesn't make any sense. For now the launch rates preclude an economically viable RLV, though partial reusability of a system may work.<br /><br />The goal needs to be getting launch costs down by whatever means possible, if it's cheaper to expend all or part of the system, then expend it. As the lower costs raise the launch rate then more reusability will become possible.<br /><br />

 

[gaetanomarano]

<br />"...X-43 program was a tremendous success..."<br /><br /><br />first Apollo models fly was in 1961, after only SEVEN years Apollo 7 was in orbit<br /><br />now X-43 (one of many spaceplanes's fathers...) is only a model that fly very well, then... in 2005+7... (while first uncrewed CEV test will fly)... the spaceplane... may be...<br />

 

[CalliArcale]

<blockquote><font class="small">In reply to:</font><hr /><p>The Scramjet technology is something that would be of more use to the military than to space flight. They would be useful for very fast weapon systems, but for the Sci-Fi's fan's beloved SSTO space plane you wind up with a need for one engine to get the thing up to the speed a Scramjet can operate at, then the Scramjet engine, then a third rocket engine since the Scramjet can't operate in space. Three engines would make for an absurdly complex space plane. Of course some of the Space Cadets have an affinity for unnecessary complexity, considering it to be more advanced. <p><hr /></p></p></blockquote><br /><br />Yes, it does seem to violate the KISS principle (Keep It Simple, Stupid, a popular engineering mantra <img src="/images/icons/wink.gif" /> ). Plus, of course, you're left having to lug those airbreathing engines around in space. Of course, one popular concept that keeps coming up, although I'm not sure it's quite time for it yet, is the idea of a two-stage RLV where the first stage is a purely airbreathing winged vehicle -- basically a very fast high-altitude carrier aircraft. Of course, there are problems there as well, chief among them the fact that scramjets require their airframe to form a fundamental part of the engine and operate in the extremely tight aerodynamic envelop fundamental hypersonic flight. Separation of the hypersonic carrier aircraft and the orbital vehicle could be very dangerous. There certainly would be little margin for error. <div class="Discussion_UserSignature"> <p> </p><p><font color="#666699"><em>"People assume that time is a strict progression of cause to effect, but actually from a non-linear, non-subjective viewpoint it's more like a big ball of wibbly wobbly . . . timey wimey . . . stuff."</em>  -- The Tenth Doctor, "Blink"</font></p> </div>

 

[j05h]

>I have a quote around from Hnery Spencer, the gist of which is that any regeneratively cooled engine is potentially reusable. <br /><br />Does Henry Spencer post here? I wondered at first if user "Henry" might be him, but (no offense) he is most defenitely not Mr. Spencer. Henry Spencer is one of the pillars of the sci.space.* community, well, before the trolls and spammers destroyed it.<br /><br />Josh <div class="Discussion_UserSignature"> <div align="center"><em>We need a first generation of pioneers.</em><br /></div> </div>

 

[j05h]

>I'll settle for a fully reusable two stage system! <br /><br />I'll settle for a $500,000 flight to orbit on any safe rocket! I don't really care if it's got wings, is/isn't reusable or has an inflight meal. CHEAP Access to Space, let the market decide.<br /><br />Josh <div class="Discussion_UserSignature"> <div align="center"><em>We need a first generation of pioneers.</em><br /></div> </div>

 

[gaetanomarano]

<br />"...shuttle will fly for some 19 more flights in the next five years..."<br /><br />there are claims that NASA Shuttle can do only two flights per year and only 8 in total (7 ISS resupply and 1 Hubble) within 2010 for technical and budget problems<br /><br />but you have seen the Discovery delays in 2005, also the next flight will have many delay and many other problems will happen at each new flight!<br /><br />I think that, within 2010, Shuttles flights will be less than five!<br /><br />your evaluation is VERY optimistic, not real<br /><br /><br />"...first flight in late 2011..."<br /><br />about CEV you are far more optimist than with Shuttle, CEV have ALREADY had this years its first delay (summer 2006 for CEV selection) and, like all complex project, it will have LOTS of delays, NOT lots of accelerations!<br /><br />after two Shuttle crash, NASA can't have rush with future crewed vehicles, it's too risky!<br /><br />revise your prediction!<br /><br />original plan was: 2012 for first simplified orbital crewed CEV flight + first 2005 delay = 2013 (not 2011, your watch runs back???)<br /><br />add one-two years of new (unexpected) delays in next years = first orbital manned CEV flight only in 2015 ! <br /><br />

 

[dobbins]

My view of SSTO is it consists of saying "It's hard to get to orbit, let's make it harder by hauling up a bunch of stuff we don't need once we get there". A two stage RLV makes more sense, however you have to keep economics in mind too. It has to have service costs that are lower than an ELV or the only thing you accomplish is making it more expensive to get to space.<br /><br />For now I think the best way to go is with a sub-sonic first stage that just uses plain old jet aircraft technology. Then your service costs are the same as with any other sub-sonic jet and the service can be farmed out to any facility that services jets. This gives you the economics of scale on servicing the first stage without having the flight rates needed to make it affordable with in house servicing. For now it will still be cheaper to use an ELV as the upper stage.<br /><br />Once you get higher flight rates then you can start looking at super-sonic first stages, and later on RLV upper stages.<br /><br />

 

[gaetanomarano]

<br />"...shuttle will fly for some 19 more flights in the next five years..."<br /><br /><br />no, last claims say "8 flights"... I think may be only ONE per year, then 4-5 flights, that may quickly fall to ZERO (in 24h!) after the next shuttle's safety problem!<br /><br /><br />"...this IS NASA's current plan..."<br /><br />it's clear that no one can predict the exact time, but, generally, big and complex plans have a lot of DELAYS<br /><br />NEVER a complex project respect the times planned, this is NOT due to NASA, all big projects (public or private) have delays: new airplanes, new cars, new processors, new ships, new softdrinks, new pizza, etc.<br />

 

[dobbins]

No, the plans are for 19 flights. As usual you are displaying an ability to ignore any and all reality if it isn't what you wish to believe.<br /><br />

 

[gaetanomarano]

"...the plans are for 19 flights..."<br /><br />no, "was" 19, in september, but I've read a few days ago (now I search the source to post the link here) that NASA can't do more than two per year, so, max 8-10 flights within 2010, or, 19 flights, but, within 2015, not 2010<br />

 

[drwayne]

"Does Henry Spencer post here?"<br /><br />Not that I know of.<br /><br /><img src="/images/icons/frown.gif" /><br /><br />Wayne <div class="Discussion_UserSignature"> <p>"1) Give no quarter; 2) Take no prisoners; 3) Sink everything."  Admiral Jackie Fisher</p> </div>