Lockheed Martin's CEV is winged!!

[starbaby57]

The next generation manned spacecraft does not have to "look" sexy, or futuristic, or cool; but it does have to perform its mission with the maximum degree of efficiency, reliability, safety, and economy possible. This is almost by definition, also a simple, clean design.<br /><br />The arguement that the lifting body is easier on the bodies of the astronauts returning to earth is weak to say the least. For earth orbit or lunar flights this is not an issue. And for Mars flights, extensive research is going into minimizing the impact of extended weightlessness by exercise, centrifugal beds, spinning on a tether, etc. To prevent the astronauts from being total invalids for much of their time after arrival at Mars, you can be sure such sytems will be used. And if they are used, the crew will be hearty enough to withstand a more ballistic return to Earth. <br /><br />One other thing that is killing me about these CEV concepts is the requirements for multiple launches to complete a single mission. Zubrin recently wrote a concise piece detailing the folly of the complexity of this approach. We need a large enough launch vehicle to put the entire lunar vehicle on its way in one shot. The Mars ship may very well require multiple launches, even if it utilized the Mars Direct approach.

 

[nacnud]

LM website for the CEV, contains the images seen previously and an interesting image showing a CEV launch and an orbital track ending in Australia.

 

[spacefire]

mrmorris:<br /><br />please review this design. yes, it is a lifting body, and it has been investigated thoroughly. had the ill-fated SLI been adopted, the OS would have probably looked like this:<br />http://www.astronautix.com/craft/hl42.htm<br /><br />It can land horizontally. Note that this was already considered a low-risk design, from back in the 80s, and it was investigate while the Shuttle was still considered reliable(before the Challenger disaster) <br /><br />also check this link for the HL20, which was design asa transfer vehicle to the space station (later it would be scaled down as the X-38 CRV)<br /><br />http://oea.larc.nasa.gov/PAIS/HL-20.html <div class="Discussion_UserSignature"> <p>http://asteroid-invasion.blogspot.com</p><p>http://www.solvengineer.com/asteroid-invasion.html </p><p> </p> </div>

 

[mrmorris]

<font color="yellow">"... and it has been investigated thoroughly..."</font><br /><br />How many of them were built?<br />How many times was it test flown?<br />How 'thoroughly' can you investigate something when it exists only as a paper design?<br /><br /><font color="yellow">"Note that this was already considered a low-risk design."</font><br /><br />Note that no one who is proposing a new spacecraft project to NASA is going to call it a 'high-risk design'.<br /><br /><font color="yellow">"...also check this link for the HL20..."</font><br /><br />...also a paper spacecraft.

 

[mrmorris]

<font color="yellow">"How many flights did Columbia have before STS-1"</font><br /><br />Excellent point. The shuttle program has met all of the goals set for it at the stage the CEV is now... NOT!

 

[spacefire]

the fact that capsules have flown more than lifting bodies is not a reason to use them again. capsules were used in the space race because it was a way to get people in orbit quick. I'm not saying cheap because a reusable lifting body orbiter who lands on a runway will have a longer service, with fewer parts replaced, than a capsule who lands/splashes down under a parachute. <br />If you envision a program like the Apollo program ,which, when ended, left no legacy of further exploration of the Moon, fine, use your capsule, fire a few shots to the Moon and Mars, then promptly forget all about it. It's not going to be cheaper, it's not going to be safer, it probably won't be any quicker, but the politicians are going to think it is, and in the end that's what counts.<br /> <div class="Discussion_UserSignature"> <p>http://asteroid-invasion.blogspot.com</p><p>http://www.solvengineer.com/asteroid-invasion.html </p><p> </p> </div>

 

[rubicondsrv]

why dose a capsule have to replace more components than the LM cev since neither can do a runway landing. and both require parachutes and some type of impact reduction on landing? <div class="Discussion_UserSignature"> </div>

 

[mrmorris]

<font color="yellow">". I'm not saying cheap because a reusable lifting body orbiter who lands on a runway will have a longer service, with fewer parts replaced, than a capsule who lands/splashes down under a parachute."</font><br /><br />Apparently, because my quote from Griffin didn't mention lifting body -- you ignored everything else in it. To repeat (broken into smaller pieces to make it a bit easier for you to comprehend.<br /><br /><i>"It is likely to be more volumetrically efficient and to have less mass than a winged vehicle for the same overall mission requirements, and <b>is much better adapted to any requirements to go beyond low Earth orbit.</b>"<br /><br />"<b>Either design can be equally reusable</b>, with the possible exception of the heat shield for the semiballistic vehicle, which will almost surely encounter a higher heat load than for a gliding entry vehicle. However, and in strong contrast to a winged vehicle, the semiballistic can be designed such that the heat shield is both very simple, completely separable, and easily detachable from the core vehicle, resulting in a system with only one non-reusable component that is not particularly weight critical and can be, almost literally, dirt cheap."<br /><br />"It is often stated that the landing accuracy of a semiballistic vehicle will be inferior to that of a winged design. <b>This is nonsensical</b>. If a parachute or parasail is used, today's steerable designs, with pinpoint GPS guidance, allow either design to achieve highly accurate landing point control."<br /><br />"Furthermore, historical data indicates that even without benefit of steerable parachutes and GPS, entirely acceptable landing accuracy can be obtained. ... It is seen that the worst-case landing dispersion would have been trivially contained within the boundaries of Edwards AFB, or White Sands Missile Range, or even within acceptable landing areas at Cape Canaveral or Wallops Flight Facility. <b>Most of the Apollo landing dispe</b></i>

 

[spacefire]

all the advantages of a capsule design apply to a lifting body as well. <br />I'm not talking about the Lockheed CEV here-that design is gonna change a bunch of times before it(if) gets built so the current configuration is irrelevant.<br />I'm talking about previous, promising designs like the HL20 and HL42 or X33. <br />In addition to the low-risk re-entry approach of a capsule,witha lifting body you have better cross-range, possiblity of landing on a runway, lower G loads during reentry.<br />If NASA supports the Lockheed CEV concept, expect a speech from Griffin where he praises lifting body vs. capsule design. Understand that Griffin(and NASA too) is in a position where they have to go not with what's best but whatever the government decides, so if congressman Smuckface or even the president says he thinks a capsule is better, Griffin will have to smile pretty and pick a capsule design and then praise it to get everybody else to accept it. I'm at least glad that Lockheed showed a bit of initiative and wisdom and chose a lifting body design, which it is most suited to build from previous experience with the X33 <div class="Discussion_UserSignature"> <p>http://asteroid-invasion.blogspot.com</p><p>http://www.solvengineer.com/asteroid-invasion.html </p><p> </p> </div>

 

[scottb50]

I think the one thing the lifting body tests proved was it wasn't the answer. True it may have nearly as benign re-entry capability as a capsule, but its descent rate and landing qualities proved to be a definite problem. Just watch the introduction to the Six Million Dollars Man.<br /><br />The Shuttle wings offer some options in case things go wrong where a lifting body would not. That being said I would have to agree with SG that a lifting body and a runway don't go together.<br /><br />Capsule obviously offer the lowest cost solution and could be in service relatively quickly using existing launchers, though the costs would still be high they could at least get things started and be used for an initial construction phase of LOE assets. For commercial operations I still think wings make the most sense, we can live with the landing characterists and logistics of a capsule as long as it is professionals involved but more control has to be available for passengers. <div class="Discussion_UserSignature"> </div>

 

[spaceiscool]

Morris. You're allowing your anti-Shuttle attitude blind you into thinking returning to the 1950's is the best option. I hate the Shuttle with a passion cause it's a death trap, but you want to send them up in flying metal hot tubs? Your patronising attitude shows you have to get all hot and bothered to defend your minority held view. Stop watching Apollo videos and work out NASA is no longer in the 1950s.

 

[mrmorris]

<font color="yellow">"all the advantages of a capsule design apply to a lifting body as well. "</font><br /><br />No. They don't. <br /><br /><font color="yellow">"In addition to the low-risk re-entry approach of a capsule..."</font><br /><br />A lifting body enjoys no such capability. It still has a high-risk re-entry. The TPS is only on the leading edges and bottom. As with the shuttle -- a lifting body is fully capable of tumbling, and if it tumbles, it fries. By contrast a capsule cannot tumble because the flight aerodynamics preclude it.<br /><br /><font color="yellow">"...possiblity of landing on a runway..."</font><br /><br />Which the Lockheed CEV concept is not designed to do. It still lands vertically via parachute. Why you think a lifting body landing via parachute is so much better than a capsule landing via parachute is a mystery.<br /><br /><font color="yellow">"Griffin will have to smile pretty and pick a capsule design and then praise it to get everybody else to accept it."</font><br /><br />Again -- the article in question is from <b>8 May 2003 </b>. Griffin was not the NASA admin two years ago, nor was he considered a candidate for it. At the time, he was simply (IIRC) the head of a committee looking into alternatives for the OSP. In that -- no government force was pushing for a capsule. His commentary on the benefits of them were not based on any <b>need</b> to put a good face on a political requirement.<br /><br /><font color="yellow">"If NASA supports the Lockheed CEV concept, expect a speech from Griffin where he praises lifting body vs. capsule design <br /><br />... Griffin will have to smile pretty and pick a capsule design and then praise it to get everybody else to accept it."</font><br /><br />So if a lifting body design is picked and Griffin praises it -- he's telling the truth. If a capsule is chosen and he praises it -- he's lying through his teeth.<br /><br />It is incredibly hard to reply

 

[padrat]

>>Lifting bodies are not safe to land on a runway ! Their approach speed is much too high as in their glide angle. The Space Shuttle orbiter is as close to a lifting body as anyone should ever consider trying to land.<<<br /><br />You're incorrect on this one, SG. The four designs flown by USAF/NASA during the 60s flew approaches that served as the proof of concept for shuttle landings. They all flew 18-21 degree glide slopes, used the concept of heading alignment circles and aim points, and made precision spot-landings at ~200 kts. They are no more unsafe than shuttle.<br /><br />That said, it must be noted that LM's use of a lifting body shape has absolutely nothing to do with the actual landing event - that will entail parachutes and airbags. Rather, the lifting entry will satisfy LM's desire to mitigate g-loading on a zero-g adapted crew and to execute a relatively pinpoint dry landing. The vehicle shape also enhances LM's ability to meet the NASA requirement of living space per crew member, something that will be harder to do with a capsule.<br /><br />BTW, yes, lifting bodies have made successful reentries from space. X-23 (PRIME) and ASSET demonstrated lifting entry in the early 60s.<br /><br />-Pad Rat-

 

[mrmorris]

<font color="yellow">"The vehicle shape also enhances LM's ability to meet the NASA requirement of living space per crew member, something that will be harder to do with a capsule. "</font><br /><br />How exactly are you figuring this? Lifting-bodies have less volume for a given mass than capsules -- so where is the extra space per crewmember coming from?

 

[najab]

I guess he's thinking in terms of 'usable' living space - the pointy end of the capsule and the volume around the base aren't accessable to the crew as living space.

 

[tap_sa]

There are lifting bodies and there are lifting bodies. Whether it can safely land on a runway depends heavily on the wing load, or in this case body load. L-M CEV's body load appears to be so high that it's aerodynamic shape has meaning only at supersonic re-entry speeds. OTOH something like X-33/VentureStar would be just a big empty tank, it might have trouble landing at all because of the boyancy in hydrogen tank <img src="/images/icons/wink.gif" />

 

[mrmorris]

<font color="yellow">"...'usable' living space..."</font><br /><br />I could easily be wrong on this -- but I don't think NASA has a 'usable living space' calculation to make this kind of determination. It's going to get *very* subjective making a determination that <b>this</b> nook over here counts as living space but <b>that</b> cranny over there does not. In general -- the crew-space calcs I've seen have simply taken total pressurized volume and divided by the number of crew on-board.

 

[tap_sa]

All hail najaB <i>the moderator</i>!

 

[padrat]

>>How exactly are you figuring this? Lifting-bodies have less volume for a given mass than capsules -- so where is the extra space per crewmember coming from?<<<br /><br />Based on the cutaways, the LM shape allows living space to extend aft to the mission module through a hatch which will not feel the brunt of reentry. It looks like a rather roomy interior, even allowing for the intrusion of systems and lockers mounted on the walls.<br /><br />The LM CEV doesn't have the classic shape of previous lifting bodies, either. It's more like what we called a sled shape during OSP. That lends itself to better volumetric efficiency than a body shaped like an HL-10 or an X-24 by creating a rectangular cabin space. <br /><br />A capsule in the pattern of Apollo will have a conical interior that will place serious limits on individual crew space, since its diameter will be limited to some extent by the launch vehicle. A tube will provide more space than a cone.<br /><br />-Pad Rat-

 

[padrat]

>>There are lifting bodies and there are lifting bodies. Whether it can safely land on a runway depends heavily on the wing load, or in this case body load. L-M CEV's body load appears to be so high that it's aerodynamic shape has meaning only at supersonic re-entry speeds.<<<br /><br />Exactly. The lifting body aspects of the shape have no use after the bulk of deceleration is done. LM has provided just enough lifting entry shape to the design to enhance the entry qualities it felt were valuable. There was never any intent on LM's part for this design to land horizontally.<br /><br />-Pad Rat-

 

[padrat]

>>Possibly so but if I am than so is John Young. he considers lifting bodys as to unsafe to fly operationally.<<<br /><br />Interesting comment from someone who never flew one, yet relied on the principles and techniques they pioneered in order to safely land the orbiter.<br /><br />It's hard to argue with history, though. The one unsuccessful landing in lifting body history was due to the pilot being distracted.<br /><br />-Pad Rat-

 

[nacnud]

<font color="yellow">It's hard to argue with history, though. The one unsuccessful landing in lifting body history was due to the pilot being distracted. </font><br /><br />What happened?

 

[padrat]

>>What happened?<<<br /><br />The pilot was on final when he noticed a rescue helicopter that he thought was too close to his flight path. When he returned attention to his landing, he was too low for complete landing gear extension. The result was the opening scene of "The Six Million Dollar Man". The pilot survived with injuries that later forced him to retire from flying duties. The test team also came to realize that the lack of landmarks on the lakebed affected pilot's depth perception, which could affect when certain tasks were performed during approach.<br /><br />-Pad Rat-

 

[spacefire]

mrmorris:<br /><br />here's lockheed's perspective and how they justify the lifting body configuration for their CEV proposal:<br /><br />"McKenzie said the lifting body design was preferred over a capsule for several reasons. <br /><br /><br />For one, that approach allows more cross-range maneuverability, thus the craft can touchdown on land versus water. Secondly, a lifting body can lessen the g-loads on returning crews from long-duration space stints, McKenzie said.<br /><br /><br />Whether they are lengthy stays in Earth orbit, a prolonged mission on the Moon, or the round-trip trauma on the human body from a Mars mission - the lifting body approach helps to minimize the g-forces on crew members, McKenzie noted"<br /><br />I believe his points are valid. He claims a capsule will have to splashdown. I believe a capsule designed to land-(intact, to be reused) will be much heavier than a lifting body that can land.<br /> <br /><br /><br /> <div class="Discussion_UserSignature"> <p>http://asteroid-invasion.blogspot.com</p><p>http://www.solvengineer.com/asteroid-invasion.html </p><p> </p> </div>

 

[najab]

><i>He claims a capsule will have to splashdown. I believe a capsule designed to land-(intact, to be reused) will be much heavier than a lifting body that can land.</i><p>Not true at all. The reason they chose splashdown for Apollo was because America 'ruled' the oceans. They had a large Navy looking for a job to do and only a few missions, which made ocean recovery an obvious choice. Compare that to the Soviet Union which was never a major naval power, and had lots of open land, and a large Army looking for a job to do. That made land recovery an obvious choice.<p>As for the actual landing, there's very little to choose between the LM lifting body and a capsule. They will both be slowly descending under a parachute, and they both will hit the dirt on their heatshields.</p></p>