New details on CEV

Page 3 - Seeking answers about space? Join the Space community: the premier source of space exploration, innovation, and astronomy news, chronicling (and celebrating) humanity's ongoing expansion across the final frontier.
Status
Not open for further replies.
G

gunsandrockets

Guest
"In Gemini when the Agena was lit "eyeballs out" it was about 1g. The Apollo SIVB/Apollo stack experienced about 1g "eyeballs in". So I guess the EDS/LSAM/CEV stack would be something similar, though eyeballs out. "<br /><br />There is no reason that the crew of the CEV must sit in the CEV when the Earth Departure Stage burns to send the CEV/LSAM stack towards the moon. The crew can sit in the LSAM during this maneuver since the CEV will be docked with the LSAM beforehand. With Apollo the Command Module docked with the Lunar Module after the TLI burn of the Saturn V third stage.<br /><br />In fact, when you consider that after the CEV docks with the LSAM the CEV doesn't maneuver again until the TEI burn, it makes more sense for the crew to pilot while sitting in the LSAM. Unlike Apollo, the CEV is the appendage and the LSAM is the main spacecraft.
 
R

rubicondsrv

Guest
Can your innovative proposal successfully execute a ballistic reentry in case of control systems failure? <div class="Discussion_UserSignature"> </div>
 
S

spacefire

Guest
the CEV should be a spaceship with a reentry lifeboat capsule (no life support, just an aeroshell).<br />TRansfer to and from the CEV should be accomplished via a spaceplane.<br />The CEV should be reusable and able to remain in LEO for long duration missions.<br />The CEV should NEVER land anywhere.<br />NASA is a bunch of idiots for going with the current design which is a technological dead-end since its centerend around the CEV capsule instead of promoting a modular design. <div class="Discussion_UserSignature"> <p>http://asteroid-invasion.blogspot.com</p><p>http://www.solvengineer.com/asteroid-invasion.html </p><p> </p> </div>
 
T

tomnackid

Guest
And how exactly is an untested design by the same people who brought you (make that "failed to bring you") Venture Star more innovative? I'm not gona spend my tax dollars to wait around with our thumbs up our buts for the nest ten years while LockMart tries to figure out how it transitions from hypersonic to subsonic speed, or how to attach a TPS to it. Besides, the damm thing lands with airbags and parchutes for god's sake! It cleverly combines the worst aspects of a capsule and alifting body! Good going LockMart!<br /><br /> It should be obvious by now that any vehicle design that originates with a big aerospace contractor is just designed to maximize the companies profits while they tweak a little here and test a little there, and "oh yeah it really will work we swear, just increase the budget a bit more wo we can add a couple more fins and paint on the racing stripe."
 
G

gunsandrockets

Guest
There seems to be considerable confusion about the relative nature of the Apollo and Soyuz reentry capsules. Both capsules are of semi-ballistic design, capable of generating some lift during reentry.<br /><br />The last purely ballistic manned capsule flown was the spherical capsule of the Soviet Voskhod spacecraft. The last American pure ballistic capsule was the conical Mercury spacecraft. Pure ballistic capsules have LEO reentry g loads of around 10.<br /><br />Because the reentry speeds from the moon are higher (11 km/s) than from LEO (8 km/s), both the Apollo and Soyuz were designed as lifting capsules to help mitigate g loading. The Apollo has a lift to drag ratio of about 0.3, while the Soyuz has a ratio of about 0.25. Even with the lift these capsules have, they undergo g loads of around 8 during reentry from lunar missions.<br /><br />The skip-reenty that the Soyuz (called Zond during tests to help conceal the true nature of the flights) used during lunar test flights had more to do with controlling where the Soyuz would land on Earth than because of inferiority compared to Apollo. The Soviets did not have the world-girdling Navy resources the U.S. did to recover returning spacecraft. It's instructive that the ESAS plan also anticipates use of skip-reentry to control where the CEV lands.<br /><br />The fact is the headlight shape of the Soyuz is superior the Apollo conical shape, for a reentry vehicle at least. The Soyuz is more volume efficient than the Apollo. And the Soyuz will safely stabilize it's orientation when not under manual control, as some hair-raising flight experiences of the Soyuz have shown. In contrast it's possible for the Apollo to stabilize in a dangerous nose forward orientation.<br /><br />On the other hand the Apollo conical shape can obviate the need for a launch shroud, as the conical shape is almost ideal for handling the aerodynamic loads of launch. Though in practice the Apollo capsule used a fully enclosing launch-shroud a
 
S

strandedonearth

Guest
The main problem I see with that design is that the TPS is left hanging in the wind, so to speak, vulnerable to all sorts of MMOD, even though it says the TPS is 'backed up' with carbon-carbon. I also wonder how much active control it would need during re-entry. It also says it needs 2 launches to launch the full (roomier) vehicle. But other than that, it appears to be a fine design, and I liked it until I realized how vulnerable it was. And NASA is currently shy about unprotected TPS's, after Columbia. Just one more thing to worry about.
 
T

tomnackid

Guest
I like the deisgn myself. I'm just not willing to put the entire space program on hold until LockMart works out the bugs! Hopefully the LEO market will heat up and LockMarat can build one for Branson or Bigelow to play with!
 
F

frodo1008

Guest
Eventually, this will quite probably be the approach that is taken, You are correct, it makes sense. <br /><br />But for now NASA has a lot on its plate!! It is the expense of both time (time to develope a true lifting body design), which WILL take more time than an enlarged Apollo type capsule, and the expense in money. It is because of this monetary expense (which IS the exact opposite of what GT says!) that is the reason that this design is going to be used in this time frame!!<br /><br />Hopefully, with NASA or DARPA leading the way with the essential initial research (and NO the very essential hypersonic research, particularily into propulsion has yet to be accomplished) into the hypersonic region. Then perhaps such as Burt Rutan's organization will actually build such Earth to LEO craft that are practical, reliable, and inexpensive to build and operate!<br /><br />However, for NASA to wait around for such would take NASA at least twice as long to even get back to the moon, let alone on to Mars!<br /><br />No, at this time this is the most pratical plan available, and that is what most on these boards are saying!!
 
G

gunsandrockets

Guest
"I know this may be a dumb question but... did they ever decide who is going to build the CEV? I understand it is between Lockheed Martin and Boeing/Northrop Grumman. Thank you."<br /><br />There are no dumb questions. (I can't say the same for answers though!)<br /><br />Originally under NASA administrator O'Keefe, there was going to be a competive fly-off and contractor selection in 2008. Under the accelerated plan of new NASA administrator Griffin, NASA has selected major design details itself and will award a contract to a single company in 2006.
 
M

mlorrey

Guest
tomnackid has a point, that Lockmart burned a lot of credibility with their lies in getting the X-33 contract, about hinting at having proven multi-lobed composite LH2 tanks in a previous black program (assuming they were lying), so it was likely NASA was never going to give their proposal much credibility at all.<br /><br />Similarly Boeing had learned, from its McD side, during the F-22/F-23 competition, that a more innovative and better performing design is not necessarily a plus with a governmental customer (apologies to my friends at Lockmart, but the F-22 is an also-ran in my book).<br /><br />It appears to me that Lockheed in many ways is where Douglas Aircraft was in the 1960's: a leader, but not THE leader, and a frequent loser in key gov't contracts despite a long history of good work. If LM were smart, it would see the writing on the wall, dump the EELV work, and really dive into independent RLV with their own assets and make it work, and fly circles about the NASA ESAS/SLV Thiokol ATK corporate welfare behemoth.
 
D

drwayne

Guest
I would not have wanted to be involved with the procurement decision on the F22/23, thats for sure.<br /><br />Wayne <div class="Discussion_UserSignature"> <p>"1) Give no quarter; 2) Take no prisoners; 3) Sink everything."  Admiral Jackie Fisher</p> </div>
 
V

vt_hokie

Guest
<i>It should be obvious by now that any vehicle design that originates with a big aerospace contractor is just designed to maximize the companies profits while they tweak a little here and test a little there, and "oh yeah it really will work we swear, just increase the budget a bit more wo we can add a couple more fins and paint on the racing stripe."</i><br /><br />Does that include the "Apollo on steroids" CEV capsule and ATK's segmented SRB launch vehicle? <img src="/images/icons/wink.gif" />
 
J

j05h

Guest
>Does it even matter? NASA basically dictated the uninspired capsule design, shooting down any more innovative proposals? So, no matter who builds it, it's just going to be a revised Apollo capsule.<br /><br />This is not the whole truth. Dr Griffin has said that they will buy any commercial transport services that are cheaper/better than what is now available. They are only underwriting the development of a largely proven design so that they aren't stuck with Shuttle grounded. Also, they are funding a few innovative concepts through NIAC. <br /><br />Josh <div class="Discussion_UserSignature"> <div align="center"><em>We need a first generation of pioneers.</em><br /></div> </div>
 
T

trailrider

Guest
"If LM were smart, it would see the writing on the wall, dump the EELV work, and really dive into independent RLV with their own assets and make it work, and fly circles about the NASA ESAS/SLV Thiokol ATK corporate welfare behemoth."<br /><br />The only problem with dumping the EELV work is that it provides money in the bank from its "other" government customer, the USAF! Without that money coming in Lock-Mart won't have the funds to do a major IRAD (Internal R&D), especially as complex as the lifting body vehcile will be. (And the fact that I once worked for Martin-Marietta has nothing to do with this statement...PLENTY of dumb mistakes were made by M-M management while I was there in the '80's.) <br /><br />NASA will issue the RFP early in 2006, but it will be for the CEV design as is. The Constellation is the fastest and least expensive and LEAST RISKY approach to replacing the Shuttle orbiter fleet and getting back to the Moon in the 2018-2020 time-frame.<br /><br />The winged Shuttle vehicle was supposed to make access to LEO expeditious and economical. It turned out to be neither, though WE HAVE LEARNED A LOT about TPS, re-entry aerodynamics, and materials that we didn't know before. Perhaps we would not have learned it had we continued with the capsule design for Earth-LEO-Earth operations. The Hubble Space Telescope would not have been repaired and proven to thusfar be the most important astrophysical tool ever built without the Shuttle's ability to carry up the parts, tools and astronauts to repair it. <br /><br />Whether we would have been further ahead with a space station or not had we taken another approach is a pointless exercise in speculation at this point.<br /><br />What HAS been a BIG disappointment to me and others of my generation who participated in various aspects of the space program from the 1950's until now is that we don't have permanent research stations operating on the Moon and are nowhere near getting to Mars! Also that my generatio
 
T

tomnackid

Guest
Does that include the "Apollo on steroids" CEV capsule and ATK's segmented SRB launch vehicle? <br />--------------------------------------------------------------------------<br /><br />Actually if I'm not mistaken the CEV and the SDLV designs originated within NASA--or "dictated" by NASA, depending on your point of view. Now I'm sure ATK is more than happy to stay in the large segmented SRB business. I have nothing against aerospace comapnies making money, even making tons of money, so long as they come through with the goods. The problem we have seen far too much of lately stems from big aerospace taking government money and using to fund paper studies and basic research and never coming through with usable hardware. I'm glad Griffin did away with the idea of a design competition.
 
J

JonClarke

Guest
Excellent post.<br /><br />Where do you get the 16Gs for a CEV reentry from? That would be painful.<br /><br />Jon <div class="Discussion_UserSignature"> <p><em>Whether we become a multi-planet species with unlimited horizons, or are forever confined to Earth will be decided in the twenty-first century amid the vast plains, rugged canyons and lofty mountains of Mars</em>  Arthur Clarke</p> </div>
 
M

mattblack

Guest
>>Rhetorical or not, here's the obvious answer to your question: <br /><br />http://www.popularmechanics.com/science/space/1534782.html<<<br /><br />YEAH RIGHT!!<br /><br />How is it I KNEW you were going to show me that piece of junk?!<br /> <div class="Discussion_UserSignature"> <p> </p><p>One Percent of Federal Funding For Space: America <strong><em><u>CAN</u></em></strong> Afford it!!  LEO is a <strong><em>Prison</em></strong> -- It's time for a <em><strong>JAILBREAK</strong></em>!!</p> </div>
 
J

josh_simonson

Guest
Can't send that behemoth to the moon, that's for sure. It'd also take two CLV launches to resupply the ISS with it. The only thing this critter could do better than the CEV would be to repair the hubble.
 
M

mlorrey

Guest
The vehicle depicted with mission module and upper stage is for a translunar mission. The Crew Module alone is ISS capable itself.<br /><br />It carries more cargo to ISS and, unlike the Son of Apollo, has an airlock (the rear compartment), to do missions to repair things like Hubble, Spitzer, and other orbital installations. It has a lower reentry g load, and with greater wetted area, less loading on the TPS, than the Clone Cone.
 
T

tomnackid

Guest
But the point is we don't NEED it to go to the moon. It might be nice for CEV Mark II, but I don't want to see Project Constellation held up while LockMart perfects it.
 
G

gunsandrockets

Guest
"Can't send that behemoth [LM lifting-body CEV] to the moon, that's for sure. It'd also take two CLV launches to resupply the ISS with it. The only thing this critter could do better than the CEV would be to repair the hubble."<br /><br />The Lockheed Martin CEV from May 2005 resembled the older wingless Kliper. The Kliper was a 14.5 tonne partially reusable lifting body with a crew of 6, life support for 10 days, 20 cubic meters habitable space and LEO maneuvering capability. The Lockheed-Martin CEV was a semi-reusable lifting body with a crew of 4, life support for 5 days, 21 cubic meters habitable space and LEO maneuvering capability (and I bet a GLOW very close to 14.5 tonnes and reclining seats just like the Kliper)<br /><br />If the Lockheed-Martin CEV was a behemoth at 14.5 tonnes, what does that make the current Apollo 2.0 version of the CEV which masses 23 tonnes? <br /><br />
 
M

mlorrey

Guest
zingo.... Moreover, the anti LB nutters ignore the fact that the Cone Clone also needs a Stick launch AND an HLV launch to put up the equipment needed for the Apolloesque to go on a moon jaunt...
 
N

najab

Guest
<blockquote><font class="small">In reply to:</font><hr /><p>Moreover, the anti LB nutters ignore the fact that the Cone Clone also needs a Stick launch AND an HLV launch to put up the equipment needed for the Apolloesque to go on a moon jaunt...<p><hr /></p></p></blockquote>And how, pray tell, would the LM CEV candidate do it without a HLV launch?
 
Status
Not open for further replies.

Latest posts