Lockheed Martin's CEV is winged! (Part 2)

[wvbraun]

"I'm sure Venture Star would have worked had they allowed it to proceed."<br /><br />The Lockheed engineers (who desgined X-33) certainly didn't think so...

 

[spacefire]

well, it certainly needed more $$$$ but the engines works.<br />interestingly enough, aerospike nozzles are still being tested long before the Venture Star was cancelled.<br />http://www.spacenewsfeed.co.uk/2004/25April2004_16.html<br /> <div class="Discussion_UserSignature"> <p>http://asteroid-invasion.blogspot.com</p><p>http://www.solvengineer.com/asteroid-invasion.html </p><p> </p> </div>

 

[elguapoguano]

the "aerospike" engine wasn't new either it was previously proposed before X-33. Linear Aerospike was a new twist on an old idea... <div class="Discussion_UserSignature"> <font color="#ff0000"><u><em>Don't let your sig line incite a gay thread ;>)</em></u></font> </div>

 

[najab]

><i>well, it certainly needed more $$$$ but the engines works.</i><p>Well great, stick that engine on the back of a 1975 Honda Civic and we'll have a spaceship!<p>Not.<p>Unfortunately it takes a lot more than an engine to make a SSTO, or any booster for that matter.<p>><i>interestingly enough, aerospike nozzles are still being tested long before the Venture Star was cancelled. </i><p>I assume you meant to say "long after the Venture Star...", but even so, there was nothing new about aerospike engines. They had been tested as far back as the 1960's and had even been considered for the Space Shuttle. What <i>was</i> new about X-33 was that they were using linear aerospike engines for TVC which would have been, I believe, a first.</p></p></p></p></p>

 

[spacefire]

TVC tested back in 2000<br />http://www.nasa.gov/centers/dryden/news/NewsReleases/2000/00-21.html<br /><br />can't find anything more recent <img src="/images/icons/frown.gif" /> <div class="Discussion_UserSignature"> <p>http://asteroid-invasion.blogspot.com</p><p>http://www.solvengineer.com/asteroid-invasion.html </p><p> </p> </div>

 

[jurgens]

AFAIK, a Northrop team actually tested a composite LH2 tank about 2 years after NASA canned VentureStar. So it COULD have worked.

 

[najab]

The questions that immediately come to mind though are (1) How heavy was it, if it wasn't significantly lighter than a comparable aluminun tank then they would still have had mass budget issues; and (b) would it have been stable over multiple flights, or would the repeated cool-heat cycles have resulted in delamination over time?

 

[jurgens]

The Press Release from Norhthrop didn't answer any of those questions, only that they succesfully built and tested a tank composed of composite materials. http://www.is.northropgrumman.com/media_news/2003_data/mn03_cryogenic_fuel_tank_test.pdf<br /><br />AFAIK, the VentureStar was also supposed to use Aluminum tanks, not composite. The X-33 needed composites because of it's size I believe. Then again I dunno, I mean, why bother with the composites if the x-33 is just the test vehicle? Does it HAVE to go to mach 13, can't it just go mach 12 for the test with an aluminum tank? I dunno, I don't build SSTO vehicles.<br /><br />But, imo the VentureStar looked like a winner to me. I still liked the DC-X/Y more though. Shame that NASA cancelled it.

 

[jurgens]

I know it was never intended to orbit newsartist, but why would it be really handy to have right now?

 

[spacefire]

"Using composite materials to reduce vehicle weight is one of <br />the keys to successfully developing a single-stage-to-orbit <br />launch vehicle. In November 1999 the X-33's composite liquid <br />hydrogen fuel tank failed during testing. An investigation <br />into the cause of the failure revealed that composite <br />technology was not mature enough for such a use. Lockheed <br />Martin proposed to complete development of the X-33 by <br />replacing its two composite liquid hydrogen tanks with <br />aluminum tanks. NASA agreed to permit them to compete for SLI <br />funding to do so. But the benefits of testing the X-33 in <br />flight did not justify the cost. "<br /><br /><br />ftp://ftp.hq.nasa.gov/pub/pao/pressrel/2001/01-031.txt<br /><br />says nothing about Venture Star<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>

 

[spacefire]

can you elaborate on other problems? <div class="Discussion_UserSignature"> <p>http://asteroid-invasion.blogspot.com</p><p>http://www.solvengineer.com/asteroid-invasion.html </p><p> </p> </div>

 

[spacefire]

but you are talking about the X33 here. it was posted earlier that teh Venture Star had Aluminum tanks by design. <div class="Discussion_UserSignature"> <p>http://asteroid-invasion.blogspot.com</p><p>http://www.solvengineer.com/asteroid-invasion.html </p><p> </p> </div>

 

[jurgens]

1207, I have heard rumors that the x-33 isn't dead.<br /><br />Also that Blue Origin is working on a vehicle similiar to the DC-X.<br /><br />of course all they are, are rumors. For now at least.

 

[rocketwatcher2001]

<font color="yellow">A capsule design is better in all the catigories you mentioned with the technology available today.</font><br /><br />If "better" means cheaper, than yes, I agree........but I don't like that definition of "better". I don't mean to single you out Shuttle_Guy, this is meant for most of the capsule folks. I'm sick and tired of our Space Program being run by accoutants on a shoe-string budget. We can afford to spend more, a lot more, The CEV is one part of our Space Program that is going to be pulling a lot of weight for a long time, and I hope we don't cut too many corners to save a buck here and there. I know for a fact that new fibers are being developed that are much stronger and heat resistant than Kevlar, and are as much a leap in technology over Kevlar as Kevlar was to Nylon in the 1970's. Sure, newer materials will need to be developed still, but it will be done. But it won't be cheap, nor do I really want it to be, actually I wouldn't mind if it were cheap, but I don't expect it to be, and I won't be put off because it's expensive. It's worth it to me to have it cost a little more, or a lot more, if it's truely "better". However, better at something isn't the same thing as better for everything, and that's why I want to have more than one design in the hanger, and use the best one for it's intended mission. That costs more in some ways, but I still think it's better. <br /><br />I'm not saying we should be wasteful, certainly I don't want to drop a dollar to pick up a dime. But to cut down the vehicle's capability to save every pound and increase it's efficency just to make a mission/program cheaper seems dumb to me. That's why I don't drive a Yugo, and my Mazda has been faithful to me since I bought it in 1991. I know that every extra pound means extra fuel, there's no getting around the laws of physics, no matter how much I'd like to, and that's why 40 years ago Grumman was given a million dollars for every pound the <div class="Discussion_UserSignature"> </div>

 

[najab]

I'm at the other end of the scale from you. I'm a 'the destination is important' kind of person. If a capsule will get us to the Moon fastest, then a capsule it is.<p>The Shuttle is a truly beautiful machine, but it was built a generation too soon. Like the article ASCAN1984 posted says, it was built before anyone figured out what they were going to do with it. Let's not repeat that mistake with the CEV.<p>Also, the CEV <b>system</b> is intended to be modular, we can use a capsule now and if it doesn't meet our needs, it can be replaced by something else.</p></p>

 

[gofer]

<blockquote><font class="small">In reply to:</font><hr /><p> If "better" means cheaper, than yes, I agree.... <p><hr /></p></p></blockquote><br /><br />Yes, capsules are *also* cheaper. But that's the thing, no arguments have been presented so far as to what what's wrong with capsules except possibly:<br /><br />1. better cross-range (a moot point in this day and age of helicopters and GPS gadgets; and capsules are NOT THAT bad at it)<br />2. slightly lower but longer lasting peak G/Heat loads (also a moot point: higher but shorter loads are actually *better* and the )<br />3. Capsules are 'cramped sardine cans' (moot point, as they DON'T HAVE TO BE if that's your pleasure [edited for clarity], but it's irrelevant given the shortness of the re-entry phase)<br />4. Capsules look oh so 'antique' and don't have the sex appeal of the X-wing * (for some reason this point is stressed THE MOST by the 'spacecraft should look like an aircraft' enthusiasts)<br />5. We need to 'do something new' because 'that's what we gotta to do to develop a better TPS' (laughable, yeah we've got all these heaps of cash so we need to make up a reason to spend it)<br /><br /> Actually, looking at the Lockheed's proposal I thought "at least it's not winged/ruddered/wheeled!" Could be much worse. I'm actually almost Okay with a 'blunt press iron' lifting body shape for the discriminating tourist, if they can be made as robust as capsules in orientation failure recovery.<br /><br />*I I'm going to find that Japanese UFO like capsule proposal I've mentioned, that baby looked like a real spaceship (unlike the aircraft shaped space wannabes) <img src="/images/icons/wink.gif" /><br /><br />

 

[rocketwatcher2001]

Naj-<br /><br />Who was it that said, "Cheaper, faster, better....pick any two."? <div class="Discussion_UserSignature"> </div>

 

[spacefire]

I maintain that lifting bodies have all the advantages of capsules plus those of winged vehicles.<br />I just don't understand why people can't see that!?!!??! <div class="Discussion_UserSignature"> <p>http://asteroid-invasion.blogspot.com</p><p>http://www.solvengineer.com/asteroid-invasion.html </p><p> </p> </div>

 

[gofer]

<blockquote><font class="small">In reply to:</font><hr /><p> ...<br />1. better cross-range (a moot point in this day and age of helicopters and GPS gadgets; and capsules are NOT THAT bad at it) <br />2. slightly lower but longer lasting peak G/Heat loads (also a moot point: higher but shorter loads are actually *better* and the ) <br /><p><hr /></p></p></blockquote><br /><br />Doh! This is unclear, of course meant that these 2 points were discussed as the possible merits of NON-capsules!

 

[rocketwatcher2001]

Gofer-<br />I don't think water landings are a good idea. They're sloppy. Gus Grissom could have easily gone down with LIBERTY BELL. I'm actually partial to the old DC-X, that was a neat way to land precisely but from a practicality standpoint, the Shuttle Orbiter does it right, and it's the only one that has ever been able to bring back a real load. <div class="Discussion_UserSignature"> </div>

 

[najab]

><i>[T]he Shuttle Orbiter does it right, and it's the only one that has ever been able to bring back a real load.</i><p>How often is this capability likely to be of use for MtM?</p>

 

[najab]

><i>A land touchdown is vital for a long duration mission.</i><p>A skill which the Russians have been succesfully demonstrating for 37 years or so with their Soyuz <i>capsule</i>.</p>

 

[gofer]

<blockquote><font class="small">In reply to:</font><hr /><p> I don't think water landings are a good idea. They're sloppy. Gus Grissom could have easily gone down with LIBERTY BELL. <br /><p><hr /></p></p></blockquote> <br /><br />- capsules can also perfectly well land on dry land (parachutes, SRMs, airbags, parafoil, pick one or many - simplisity itself + redundancy) and have been doing that for decades<br /><br />DC-X? I like it too. Too bad it's in limbo now. <br /><br /><blockquote><font class="small">In reply to:</font><hr /><p>the Shuttle Orbiter does it right, and it's the only one that has ever been able to bring back a real load. <p><hr /></p></p></blockquote><br /><br />- there is nothing to bring down from space, and I mean that conceptually; broken sattelites? that's a folly as has been demonstrated by the Shuttle Orbiter, what else do you want to bring back that is in the multi ton range? and do you really want to combine heavy cargo with crew, and on reentry no less?! Maybe some astronaut's personal mementos/photographs/pets maybe - that's kilograms though; <br /><br />Another thing for some reason folks think capsule means "can't be reusable" That is incorrect! There is nothing in the capsule design that precludes reusability, and in fact it's *easier* to make a capsule reusable than a winged spacecraft. Slap on new TPS, pack in new chutes, re-load SRMs/airbags, change the fuses in the power bus, and up we go again!

 

[najab]

><i>Besides the MOL Gemini testbed, how many capsules have been reflown?</i><p>Besides the...er...hmm. How many lifting body vehicles have flown even once? <img src="/images/icons/tongue.gif" /></p>

 

[rocketwatcher2001]

<font color="yellow">How often is this capability likely to be of use for MtM?</font><br /><br />So why are we going to Mars? If it's just to go there and come back with some rocks, not to return for 30+ years, than sure, use some dinky capsule. Use Apollo itself with a bigger service module. If your purpose is to build a Space Transportation Network that can sustain a moonbase and long term Mars missions that are really worth doing, you're going to need a lot better than that. <br /><br />I know I'm pissing into the wind here, we're probably not going to build that network anytime soon, I may never see it, even though we could/should. <div class="Discussion_UserSignature"> </div>