Transterrestrial Musings

Comments

Holy Pteradactyl Batman! It has wings! That will work well on the Moon and Mars!

Posted by rod at May 2, 2005 09:32 PM

Its Kliperific

Posted by dj at May 2, 2005 09:38 PM

Doesn't shock me much. Looks very cool, don't know how practical it is. My thoughts are at Lockheed's CEV
or just click on my name, as it is at the top.

Posted by Dan Schrimpsher: Space Pragmatism Blogger at May 2, 2005 09:44 PM

Not a huge surprise. I assume the "wings" are actually a lifting body shape for atmospheric entry and limited cross range. So this isn't "shuttle II", it's "mini-shuttle II". It looks a little bit like a scaled up reentry vehicle, but i suppose we're not supposed to notice that.

Why won't anyone do Vertical Landing? Wimps. Where are they getting the ocean to land in on Mars or the moon?

I think this whole approach is wrong. Landing on Earth is *way different* than anywhere else. It should have a different vehicle. It imposes trades on your vehicle that are very wrong elsewhere (like wings for instance).

There should be a space to space or maybe space to moon surface vehicle *and* an Earth to Space or vice versa vehicle. You could somewhat carefully land a space to moon surface vehicle on Mars, if you were clever.

I suppose they think it'd be too expensive to build *two* vehicles, but it doesnt have to be. Private space companies could build the Earth to Space vehicle easily (and maybe the Space to lunar surface vehicle, actually, that one would be *easier* to build, except for the testing). Building a vehicle of this size is a *much* simpler problem than building a Space Shuttle. It shouldn't cost more than 50-100 Million *at the most* to develop the vehicle independent of the launcher (which will probably be something in the Ariane 5 class, I'd guess).

If LockMart can't get a vehicle of this size flying on an a Delta/Atlas/Ariane style launcher by 2010, they should *get out of the aerospace business* and let someone else do it.

If NASA said "we give $100M + the cost of the 2 test launchers to the first person to build a vehicle of this capability and fly it to space twice in 30 days", there'd be 3 companies working on it tomorrow, and 2 of them would fly by the end of 2009 for sure. Think of it as an *INSURANCE POLICY* NASA! For 1/10th the cost of X-33. It only costs you $100M plus the cost of the 2 launches if someone wins, and *nothing* if no one does. I dont know if 100M is the right price or not, but i bet that would work. (the winner would certainly have a leg up bidding on the several vehicles NASA would have to buy to support the exploration program, now wouldn't they?)

Do that for *both vehicles* and you could have a family at $100M per vehicle design and it would *include* a demonstration. Better than spending $500M just on CAD files from LockMart! (Bet it costs that much before the first piece of carbon gets laid up.)

Ironicly, i have have investments in space companies that could build *both* vehicles...

-jcp-

Posted by Joe Pistritto at May 2, 2005 11:14 PM

If it's supposed to land by parachute, why does it have wings? Do they provide stabilty during it's nose down re-entry? A crosstrack ability to get it nearer the recovery area in bad weather? If the latter, then why not include some kind of skid for a true landing?

I'm actually rather depressed by this whole concept. 35 years later to replace the Shuttle with something less capable than Dyna Soar. Von Braun must be turning in his grave.

Posted by K at May 2, 2005 11:22 PM

> I assume the "wings" are actually a lifting body shape for atmospheric entry and limited cross range.

There's nothing to indicate that in the top view, which certainly appears to have wings. The cross section looks like a different design, which might possibly be a lifting body.

> Why won't anyone do Vertical Landing? Wimps. Where are they getting the ocean to land in on Mars or the moon?

Apparently, they are doing vertical landing. Note the parachutes and airbags. However, they still need enough manuevering capability to ensure they reach the recovery area. Apollo could count on the US Navy to cover all contingencies, but the Navy has other things to do right now.

Posted by Edward Wright at May 3, 2005 12:23 AM

> If it's supposed to land by parachute, why does it have wings?

To mitigate gee forces, which are higher on return from the Moon than from Earth orbit.

> I'm actually rather depressed by this whole concept. 35 years later to replace the Shuttle with something
> less capable than Dyna Soar. Von Braun must be turning in his grave.

Von Braun had nothing to do with DynaSoar. Perhaps you're thinking of Dornberger.

Posted by Edward Wright at May 3, 2005 12:26 AM

safety-Safety-SAFETY

Well from what I scanned over at Popular Mechanics, it's clear the overiding design feature of the Lockheed CEV is crew safety.

The wings for hypersonic gliding give maximum crossrange during re-entry. The parachute and airbags are good for ground or sea landings. And, I think, this CEV has a crew escape module similar to an F-111 that could eject during the boost phase.

Compared to previous manned spacecraft, this design can land almost anywhere on Earth, and the crew could safely abort at almost any time.

the Dynosoar flys again?

Aside from safety features, this CEV seems to have a rear end docking adaptor/tunnel similar to the Russian Kliper. As opposed to the aluminum Shuttle, this CEV is mainly titanium. Power is from fuel cells instead of solar cells. And most fun of all, this CEV looks very much like a scaled up X-20 Dynosoar.

The Competition

I think the Boeing CEV is going to resemble a 4 man Soyuz, if it hews to Grumman ideas for a CEV. The Boeing CEV would be cheaper and lighter, but the Lockheed CEV may be safer. The Boeing "Soyuz" design is better for beyond LEO missions, and the Lockheed "Dynosoar" design is better for LEO missions.

Heck, why not buy both? (just kidding)

Posted by Brad at May 3, 2005 02:09 AM

oops

That's Dynasoar, not Dynosoar. My bad.

Posted by Brad at May 3, 2005 02:20 AM

Whew! I was getting worried.

Thank god we have Lockheed around to reinvent the Dynasoar!

All of this busy work is irrelevant anyways.

I think the Bush administration is just putting on a good face for the press and congress, while anticipating that their needs will be met much sooner by Burt Rutan, Bigelow, etc.

Enjoy the pretty pictures, because that's all you'll get out of Lockheed.

Posted by Jeff Roche at May 3, 2005 05:20 AM

We seem to be assuming that this configuration of the crew module would make the trip beyond LEO to the Moon or Mars and back (with the addition of the other needed modules).

I'm not an engineer, so I'll ask: Is there a reason to do this? What's wrong with a configuration that partitions Earth-to-LEO capabilities in a separate vehicle, with LEO and beyond travel confined to another vehicle that can be designed and built without concern for Earth launch or reentry.

Is it the cost and complexity of building and launching 3 distinct vehicle systems: Earth-LEO; LEO-Lunar/Mars orbit; Lunar/Mars orbit-surface?

Posted by billgb at May 3, 2005 06:21 AM

What's wrong with a configuration that partitions Earth-to-LEO capabilities in a separate vehicle, with LEO and beyond travel confined to another vehicle that can be designed and built without concern for Earth launch or reentry.

Good question.

Posted by McGehee at May 3, 2005 06:32 AM

In fact, come to think of it, even the moon missions used separate vehicles in a limited way -- although the CSM was launch cabin, flight cabin, and, absent the SM, re-entry vehicle, the LEM was never intended to re-enter earth's atmosphere.

Posted by McGehee at May 3, 2005 06:35 AM

This vehicle doesn't go to the Moon. Or Mars. The LM (modern version called LSAM--Lunar Surface Access Module) is not part of the vehicle shown here. The only part of this that would go to the surface is (perhaps) the mission module, though we won't know for sure until we see a mission profile.

Posted by Rand Simberg at May 3, 2005 06:41 AM

"...but having that much L/D is a problem for the launch vehicle, because it will impart bending loads (for which it's not designed) on it from the side force of the lift. "

Pardon my layman's ignorance, but isn't lift highly dependent on angle of attack? That is, why can't a hypersonic glider during launch generate zero lift (and therefore zero bending forces) by fixing it to the booster with an appropriate angle to the direction of flight?

Posted by Brad at May 3, 2005 06:42 AM

Because lift (and the angle of attack that maximizes it) is also a function of velocity, and picking a single angle wouldn't work throughout the trajectory. In addition, picking a zero-lift angle would add a lot of drag. This has always been a problem for lifting bodies on top of ELVs, particularly EVLs that weren't designed with them in mind.

Posted by Rand Simberg at May 3, 2005 06:45 AM

Hmm, the people are sitting facing the pointy end of the craft. What would be the re-entry attitude? I assume it comes belly first high up there and then transforms to airplane-like gliding at some point like the shuttle. This design still has the vulnerable leading edges like the shuttle. And why an escape capsule if the whole thing is going down with parachutes anyway? During launch?

Also notable is they launch this stack of 3 pieces separately! No heavy lift. I don't really get what mission would it be for a 40-ton craft. Lunar flyby? Or would they attach more stuff to the mission module? Then it'd be like a cruising mini space station, which makes sense. :)

I also wonder how much orbital maneuvering capability the crew module has on its own... They can't use the launcher upper stage for everything, can they? Could it resupply ISS?

All this makes me slightly believe Boeing will take this one home - their design _should_ be a lot lighter and simpler with a lot less things to go wrong - although it might be less "sexy".

I know this is a bad analogy, but still this whole two schools, wings vs capsules makes me think of airships vs airplanes - people don't really get the fundamental difference of the medium of air compared to water (going to space and back vs moving through air at low speed), and thus the different optimal solutions.

Posted by meiza at May 3, 2005 06:47 AM

Rand, do you mean the crew module shown in the sketch would remain in LEO, while the LSAM traveled to the Moon, or that the LSAM would be docked with the crew module for the trip and make the actual landing from Lunar orbit, as in Apollo?

I've always thought that the technology and logistics of getting to and from LEO differ enough from that needed for travel beyond LEO that it makes sense to allow form to follow function and design vehicles appropriately. E.g., a vehicle that's exclusive to LEO, a "tug" and crew module that's exclusively LEO to Lunar orbit and return, and a lander that stays in lunar orbit when it isn't in use.

Can my suppositions be substantiated?

Posted by billg at May 3, 2005 07:36 AM

It could be that LM is thinking of an "interchangeable" system; you have a number of common interface connections, and you can create whatever kind of vehicle you want by plugging bits into each other. Quick trip to the Space Station--put a CM on top of a Deltlas. Science mission--send the crew in a CM, shoot up a customized MM. Satellite servicing--send a CM with crew, an MM with an airlock and a toolbox, and a PS to get them into the right orbit. Moon mission--send a CM with crew, a big PS, and a few MM; Assemble the MM and PS in orbit, transfer the crew from the CM, and take off (the CM stays behind.)

Posted by DensityDuck at May 3, 2005 07:51 AM

Posted by DensityDuck at May 3, 2005 07:52 AM

The latter. I the winged thing would stay in lunar orbit, and the mission module would probably go down with the LSAM and return. Then just the winged part would come back to earth. At least, that's how Boeing's concept in the architecture studies generally works.

Posted by Rand Simberg at May 3, 2005 07:57 AM

but having that much L/D is a problem for the launch vehicle, because it will impart bending loads (for which it's not designed) on it from the side force of the lift. It will be interesting to see how they explain this.

Took the words out of my mouth.

Posted by Dave at May 3, 2005 08:41 AM

I'm an amateur so maybe I'm missing something but this seems an odd choice. Wings?

I would assume the system starts in LEO. Let a ship specially designed for Earth access deal with getting to and from LEO. They'll probably be advancing and changing and improving that and you don't want to redo your interplanetary ship all the time, or put it through the stresses of reentry. Put module in orbit and connect them in orbit and then the ship should never look back.

I'd prefer a simple Command Module and Service Module arrangment (not too different from Apollo), perhaps with some kind of hub between the two that would have six airlocks (two serve to connect the Command and Service Modules and four can be used to attach either two or four transhabs for the eventual trip to Mars.

Again I'm an amateur but I'd probably leverage the ISS as well. Use it as a docking and storage barn during vehicle assembly and between missions. Perhaps we could get some use out of the albatross after all.

Posted by rjschwarz at May 3, 2005 08:54 AM

To accomplish lunar landing, Zubrin's idea (IIRC) is to mate the CEV with an unpressurized cab that lacks any life support.

CEV + LSAM module mate and land together on the lunar surface. After lift off, the LSAM module goes and parks somewhere secure (like L1) and CEV flies back to Earth.

Extended presence in low lunar orbit will degrade the crew and if left uncrewed, a CEV in LLO might get itself into trouble.

= = =

L1 makes a dandy place for a station to "switch trains" between an Earth to L1 CEV and an L1 to Luna landing system.

Posted by Bill White at May 3, 2005 09:00 AM

The second half of my post was a failed attempt to quote Joe Pistritto.

Posted by Bill White at May 3, 2005 09:03 AM

I'm wondering it they're intending to use the wings for more than reentry. Maybe they want to be able to do aerocapture and aerodynamic plane change?

I'd also be interested in seeing if they plan to cool the vehicle with a scheme that's adaptable to ET materials (for example, transpiration cooling with water).

Posted by Paul Dietz at May 3, 2005 09:40 AM

That sounds way too innovative and visionary for Lockmart, Paul.

Posted by Rand Simberg at May 3, 2005 09:42 AM

Hm. Kliper meets DynaSoar. Why don't we just build Dyna Soar then? It's not as if we don't have the data or material engineering skills. Hell, the prototype model is probably still lying around somewhere. Dust off the measurements, replace the Inconel with advanced materials... why re-invent the wheel?

Anyway, this isn't a bad design, exactly... but I'm still going to hold out for a "keel and block" modular design. In other words, I think the best approach would be to design and engineer a Spaceship Common Keel, or SCK (a pre-wired and pre-plumbed diagrid truss, with engines at one end and a railway-mounted arm along its length) and then configure the CEVs using standardized "clip-on" blocks (fuel tanks, engine modules, crew modules, etc.) that attach to the keel (using the arm) in whatever confuguration is needed.

Posted by B-Chan at May 3, 2005 09:58 AM

Kinda late in the game to be talking about differences between a Boeing version and a Lockheed version:

http://tinyurl.com/dagtc

Posted by Ed Minchau at May 3, 2005 10:03 AM

Well its a little hard to comment on this becuase of the lack of a mission concept document to go with the eye candy. They *did* drop tiles from the TPS which is a nice move. I suspect the wings are there to reduce heating loads by increasing drag high in the atmosphere. Not a horrible plan, but this vehicle should definately be Earth to LEO only. Maybe that's the plan, but we wont know until Lockmart says...

On the other topic of my original post, i think an Earth to LEO (or a Space to Space/Lunar landing) vehicle is an *excellent* use of an X-prize-like competition. The Earth to LEO vehicle is probably the easiest to do this with (because we can test it easily).

NASA should be doign that as a backup to whatever LockMart/Boeing are bidding. It would add almost negligible cost to the program (in fact, just having it happenign will probably *reduce* the Boeing/LockMart bids by more than the cost of the prize if awarded over the life of the program). Whats more, I think this fits with the new administrator's desire to encourage the private markets while doing the job he has to as a public official to ensure certain things are done by someone.

-jcp-

Posted by Joe Pistritto at May 3, 2005 11:08 AM

If its a lifting body then you could make an opposing aeroshell shaped in such a manner as to counter-act the lifting force attach it to the dorsi of the vehicle. This could in turn be jettisoned during ascent. If it turned out that bulk weight became more of a concern then drag then possibly a spoiler mechanism of some kind could be incorporated.

Posted by Josh Reiter at May 3, 2005 11:22 AM

They will probably just put a big shroud on it to eliminate aerodynamics on the CEV during launch. That would be the LockMart Way.

Posted by Patrick at May 3, 2005 11:36 AM

Just to bang on this point, look at the plan view--it's quite obvious they're going to enclose the thing in a symmetrical shroud, as the "wing" span is only slightly larger than the upper stage, and there's all those knobbly bits in between.

Posted by Patrick at May 3, 2005 11:42 AM

Wow, this looks like two engineers sat down with pictures of shuttle, Kliper, the Kistler-k1 and Boeing's CEV and said--how can we come up with something that melds these all?

Posted by cuddihy at May 3, 2005 12:14 PM

> safety-Safety-SAFETY

No, a vehicle designed for safety wouldn't use parachutes, which are unreliable at worst and make for a rough landing at best.

To ensure safety, you need a robust landing mode, that probably means powered vertical or horizontal landing, unpowered horizontal landing at the very least.

More importantly, you need a vehicle that can be tested repeatedly. Reliability generally follows a standard learning curve. On the first flight, there's a certain probability of failure, call it Pf. On the second flight, the probability will be Pf2, which is 80-90% of Pf. On the fourth flight, it will be Pf4, which is 80-90% of Pf2. And so on. Each time you double the number of flights, you get a 10-20% improvement.

This curve applies not only to designs, but also to individual serial numbers. For a vehicle to be truly safe, it has to be reliable, so that it can be flown repeatedly to get past the early "infant mortality" part of the learning curve.

That, again, requires a robust landing mode. Parachute landings are hard landings, even if you hit your planned drop zone (which is by no means certain). It's hard to design a vehicle that can survive such landings once, let alone repeatedly. (The Canadian Air Force once dropped a bulldozer by parachute and broke the bulldozer.) Even the Russian Mercur capsule, which was designed to be reused, was considered to be good for only seven flights.

> The parachute and airbags are good for ground or sea landings.

It would be more accurate to say "equally bad" for ground or sea landings. What happens if you come down in a remote area of the ocean in a high sea state? You can't count on having carrier battle groups covering every possible drop zone -- not if the US wants to continue the global war on terrorism. What happens if you come down on sharp rocks, which puncture the air bags, or on the side of a steep slope? There are a lot of possible failure modes.

The argument that "Apollo and Soyuz did it" is not convincing. Those programs never had high flight rates. They were basically counting on the fact that the program would end before they had a really bad day and killed someone. If we're ever going to get past trivial flight rates, we need to design vehicles that assume there *will* be bad days (many of them) during the service life of the vehicle.

> And, I think, this CEV has a crew escape module similar to an F-111
> that could eject during the boost phase.

You mean "similar to an F-111 capsule that could eject and usually kill the crew." Escape capsules are notorously unreliable. Ejection seats are better, but even they are far from perfect. Even a "successful" ejection often results in hospitalization and may end a pilot's career permanently. No one in aviation takes ejection lightly. Pilots call it "attempted suicide to avoid certain death." It's the last resort for aircraft designers, something a pilot can do when everything else has failed. The CEV program considers it a first resort, so they can avoid developing a reliable (testable, savable, reusable) launch vehicle. Once again, they're counting on the fact that CEV will never fly very often and, with luck, the program will be cancelled before they have that bad day and kill someone.

> Compared to previous manned spacecraft, this design can land almost
> anywhere on Earth, and the crew could safely abort at almost any time.

No professional would consider ejection is a "safe" abort. Airliners are not designed to landing "almost anywhere on Earth," for good reason. Most places are not safe to land. A safe vehicle is designed to return to a planned landing site with a very high degree of probability. Being able to eject or to survive a crash anywhere on Earth does much less to enhance safety than avoiding an ejection or crash in the first place.

Posted by Edward Wright at May 3, 2005 12:25 PM

The space.com article has a cutaway showing more of a lifting body shape (in the far right column, top pic):

http://space.com/businesstechnology/technology/050503_cev_nasa.html

Posted by Tom Hill at May 3, 2005 12:34 PM

40 metric tons! And that's just for an Earth-orbiting mission, by the looks of it.

Sounds like it's mostly about selling Atlas V-Heavy, many many many times.

Posted by Erik Anderson at May 3, 2005 12:35 PM

Boeing and Lockheed have joined their lauch companies in order to "save you money". What do you plan to do with all the tax dollars they save you?

http://www.washingtonpost.com/wp-dyn/content/article/2005/05/02/AR2005050201445.html

Posted by Dfens at May 3, 2005 12:38 PM

> They *did* drop tiles from the TPS which is a nice move. I suspect the wings
> are there to reduce heating loads by increasing drag high in the
> atmosphere. Not a horrible
> plan, but this vehicle should definately be Earth to LEO only.

Not necessarily. NASA apparently wants the cis-lunar vehicle to have a direct Earth return capability for safety reasons. The Apollo 12 scenario. (T-Space is proposing a flotilla of vehicles as an alternative way of achieving safety.)

It's even possible for a winged vehicle to be the return stage of a lunar lander. Some of Von Braun's early concepts did that. Since this program is the latest incarnation of Das Marsprojekt, it wouldn't be too entirely surprising if it came up again. Arguably, having such a vehilce on the Moon might be useful in extreme emergencies, even if it's inefficient for routine logistics.

> On the other topic of my original post, i think an Earth to LEO (or a Space
> to Space/Lunar landing) vehicle is an *excellent* use of an X-prize-like
> competition. The Earth to LEO vehicle is probably the easiest to do this
> with (because we can test it easily).

On the other hand, the delta-vee for a suborbital vehicle closes matches the delta-vee for a lunar lander, so you could use suborbital VTOLs to test at least some of the capabilities of a lunar lander. Consider a "survivor" type contest where a VTOL must take off, demonstrate a delta-vee comparable to a lunar descent, then land at an unprepared flight. The crew must camp out in the vehicle for several days, with only on-board supplies. At the end of that time, they must fly back to the original launch site. The vehicle cannot be refueled between flights, and if there is any maintenance, it must be done by the flight crew, using on-board parts. No resupply is allowed.

Such a competition would demonstrate stored propellants and maintainability as well as VTOL techniques and mass fraction. It would also demonstrate team capabilities. A team that can do this on Earth, in a one-gee field, should be capable of building a similar vehicle that can do it on the Moon.

NASA could do this at White Sands in conjunction with the X-Prize Cup. The "campout" portion of the test might even be televised as part of a reality teevee show.

> NASA should be doign that as a backup to whatever LockMart/Boeing are
> bidding. It would add almost negligible cost to the program

Calling it a "backup" to Lockheed/Boeing is a bad idea. It would give the large companies an incentive to have their lobbyists undermine the program.

Posted by Edward Wright at May 3, 2005 12:56 PM

> They *did* drop tiles from the TPS which is a nice move.

That's not certain. The website says the TPS is carbon-carbon, but there's no indication how it's applied. Also, the pictures on the second page show that upper surface is white, so apparently there are (at least) two separate TPS materials.

Posted by Edward Wright at May 3, 2005 12:59 PM

> This design still has the vulnerable leading edges like the shuttle.

Oh, bog! Aircraft have had accidents when tires blew on landing. Do you think we need to stop flying land planes and go back to floats because of "vulnerable" tires?

> And why an escape capsule if the whole thing is going down with parachutes
> anyway? During launch?

If you think leading edges must always be "vulnerable," then the escape capsule provides a solution.

Of course, there's no reason to believe that leading edges are an unsolvable problem any more than blown tires on airplanes are an unsolvable problem. The Columbia accident is merely being used as propoganda by those who to say NASA has "proved" reusable vehicles are impossible, so the only viable space policy is Return to Apollo.

Posted by Edward Wright at May 3, 2005 01:07 PM

>>>i think an Earth to LEO (or a Space
to Space/Lunar landing) vehicle is an *excellent* use of an X-prize-like
competition..."

I'd opt for a competition to build a vehicle, crewed or not, to bring the trash, completed experiments, and old equipment racks back from ISS. That's going to be an issue once the Shuttle stops flying permanently.

Posted by at May 3, 2005 02:09 PM

Check me if I'm wrong here, but leading edges are only "vulnerable" if you have something heavy above them in the launch stack that can get loose and hit them. "Son of Dynasoar" may have problems, but wing leading edge "vulnerability" - excluding possible bird strike on ascent - is not one of them.

Posted by Dick Eagleson at May 3, 2005 02:53 PM

The LockMart CEV doesn't have any windows! Too bad for the government astronauts; private space tourists will have a better view.

Posted by John Kavanagh at May 3, 2005 03:13 PM

My bad - it does have windows - way in the back.

Posted by John Kavanagh at May 3, 2005 03:14 PM

Edward Wright

You might have noticed the NASA requirements for the CEV said nothing about reusability. And why shoud they? What's the point of reusing a tiny CEV when a massive booster stack is discarded for every mission?

And as for safety, it's silly to claim that the ability to land in a greater number of places on Earth or the ability to eject is a bad thing! Too bad the Challenger shuttle didn't have a "death trap" escape capsule in 1986, eh?

Posted by Brad at May 3, 2005 05:07 PM

Just saw the space.com article. It's much better than the popular mechanics link. Much more detailed image of CEV.

It's now clear the LockMart CEV is not winged, it is instead a lifting body. And there are two mysterious components labeled "Active Thermal Control" and "Multi-Fluid Evaporative System". Is this CEV going to use active cooling as part of its Thermal Protective System? I remember just before Rotary Rocket collapsed they were talking about using water for active cooling for thermal protection during re-entry. Is LockMart going the same direction?

Posted by Brad at May 3, 2005 05:41 PM

Not DynaSoar, instead Martin W-1

http://www.astronautix.com/craft/apollow1.htm

The LockMart CEV is not so much the rebirth of the winged X-20 DynaSoar so much as it is the rebirth of the Martin W-1 command module proposed for Apollo.

"Martin's W-1 design for the Apollo spacecraft was an alternative to the preferred L-2C configuration. The 2652 kg command module was a blunt cone lifting body re-entry vehicle, 3.45 m in diameter, 3.61 m long. The propulsion, equipment, and mission modules were identical with those proposed for the L-2C baseline. The RV shape was heavier than the W-1 but provided higher manoeuvrability (hypersonic L/D ratio of 0.75). Flaps and a parachute landing system being used for final recovery were used as in the L-2C. The circumlunar version had a total length of 11.4 m including a short launch escape tower and a fuelled mass of 6,677 kg.

A single crewmen was seated in the forward part of the vehicle, with the other two behind, in couches that rotated 90 degrees from launch to re-entry positions. A jettisonable mission module (not used on the circumlunar version) could also serve as a solar storm cellar, a laboratory, or even the descent stage of a lunar lander."

Check that out. Even the "mission module" is familiar.

Posted by Brad at May 3, 2005 05:55 PM

With the Lockheed design now shown, it retains a good amount of the old HL-10 Lifting Body shape. In my jsut releasing book" The Next Shuttle", I spoke about the Capsule vs Lifting Body battles. Along with the Engineering and history at Edwards AFB. Discounting the X-33 failure due to its compsite tank problem and lower than expected engine Isp , we can conclude the following: (1) A Lifting Body has better cross range, (3) Lower heating rates during reentry allowing for reuse ( capsules c can not do that ), (3) Volume effecientcy will allow for at least a crew of 6. (4) Gee loads will be in the 4 - 6 range. Capsules are in the 8-12 range.

At Edwards during the Space Wedge effort and the X-38 the GPS sytem coupled with a para wing offers landing performance than removes the "landing at sea cost and infstructure of a capsule. In fact I did extensive CFD work in my book and the parawing was impressive and low mass. So I give a thumbs up to Lockmart for doing its homework. Its the right design.

Dave Ketchledge member NAR and TRA

Posted by Dave Ketchledge at May 3, 2005 07:13 PM

Dave Ketchledge member NAR and TRA

Posted by Dave Ketchledge at May 3, 2005 07:13 PM

Dave Ketchledge:
>Gee loads will be in the 4 - 6 range. Capsules are in the 8-12 range.

http://www.russianspaceweb.com/soyuz.html

says: Descent G-loads 3-4 g

Is that wrong?

Posted by meiza at May 3, 2005 07:22 PM

> You might have noticed the NASA requirements for the CEV said nothing
> about reusability. And why shoud they?

You mean apart from the fact that reusable vehicles are cheaper to develop? No reason at all -- unless the goal is to enable the development of cheap, safe, routine spaceflight, rather than impede it.

Why should NASA want yet another expendable capsule (YAEP)?

> What's the point of reusing a tiny CEV when a massive booster stack is
> discarded for every mission?

You're asking the wrong question. What's the point of discarding a massive booster stack for every mission?

> And as for safety, it's silly to claim that the ability to land in a
> greater number of places on Earth or the ability to eject is a bad
> thing!

No, what's silly is to claim I said such a thing.

There's a difference between having an ejection system, as a result resort, and believing that an escape system removes the need to give pilots any other option in an emergency.

> Too bad the Challenger shuttle didn't have a "death trap" escape capsule
> in 1986, eh?

Your argument is broken in a fashion that makes it irrelevant to this discussion. Let me fix it for you.

Do you think it's simply better to stick in an escape capsule, however unreliable, rather than address the basic safety and reliability of the design? If that's the case, why bother building a new CEV? Why not just stick an escape capsule into the current Shuttles?

Would you ride in an aircraft that crashed on 2-5% of all flights? Even if it had an escape capsule that gave you a better than 90% chance of surviving (better than escape capsules have historically done)? With the recognition that even if you do survive, the landing might live you with injuries that would plague you for life?

Would you be willing to fly in such an aircraft repeatedly? Say once a month, or once a week?

Or do you think we should just accept that spaceflight will always be rare and no one will ever fly in space more than once or twice in a lifetime, so long-term reliability is not a problem?

Posted by Edward Wright at May 3, 2005 07:26 PM

Volnerable leading edges: the design is described as having ablator backing up the carbon-carbon, which I interpret as a defense-in-depth against burnthrough. If the CC cracks you'd lose the ablator behind it, but presumably it would be thick enough to prevent catastrophe.

I think the presence of both of these inidicates they do want to reuse the vehicles (otherwise, why not use just the ablator?)

"Active Thermal Control" and "Multi-Fluid Evaporative System": I'd guess these are to cool the vehicle in space, or possibly to dissipate what heat leaks through the TPS during reentry.

Posted by Paul Dietz at May 3, 2005 07:26 PM

oh master of the non-sequitar Edward Wright

I'm not going to respond to you anymore after this post, it's not worth it. Since your problems are with the NASA specifications, leave me out of it. If you want to complain about NASA fine, just don't refer to me or anything I post as your method of complaining. I'm sorry I ever reacted to your post which criticised my first post about the CEV in this thread.

Posted by Brad at May 3, 2005 07:49 PM

> Lower heating rates during reentry allowing for reuse ( capsules c can not do that ),

The Russian Mercur capsule was designed to be reused seven times, according to the manufacture. You're assuming heating is the only thing that will limit reuse, which is not the case. NASA's X-38 models never tested reentry and therefore suffered no heating, but their reusability was limited because they often suffered damage on landing.

> At Edwards during the Space Wedge effort and the X-38 the GPS sytem coupled
> with a para wing offers landing performance than removes the "landing at
> sea cost and infstructure of a capsule. In fact I did extensive CFD work
> in my book and the parawing was impressive and low mass.

It's low mass, until you consider that parachutes often fail to deploy. If you add a backup parawing, the mass starts to become similar to a winged vehicle. Landing performance isn't similar to a winged vehicle, however. X-38 hit at a vertical descent rate up to twice that of a carrier aircraft. That's impressive only if you like hard landings. It may eliminate the infrastructure of a recovery fleet, but there is an even greater infrastructure required to replace or repair capsules after landings like that.

> So I give a thumbs up to Lockmart for doing its homework. Its the right design.

Right design for what? If the goal is to build the "Next Shuttle" (another expensive vehicle that limits NASA's access to space for another 20 years), perhaps. For anyone who wants real access to space, this "capsule vs. lifting body battle" is a sideshow.

The real debate should be whether we want another capsule (even one shaped like a lifting body) or a reusable spacecraft. Not a "reusable" capsule that can survive a crash landing under a parachute six or seven times, but a vehicle designed for rapid reflight with minimal maintenance, like an aircraft.

Unfortunately, that debate never took place. NASA simply decide it had already "proven" that reusable vehicles were impossible and the only possible future space program was a repetition of Project Apollo.

Posted by Edward Wright at May 3, 2005 07:55 PM

Edward Wright:
>X-38 hit at a vertical descent rate up to twice that of a carrier aircraft.

That's why this has airbags.

Posted by meiza at May 3, 2005 07:59 PM

--- "Active Thermal Control" and "Multi-Fluid Evaporative System": I'd guess these are to cool the vehicle in space, or possibly to dissipate what heat leaks through the TPS during reentry. ---

Thinking about this I wondered, what advantages could active cooling give over a purely passive TPS? Perhaps a little bit of fluid could go a long way towards reducing peak temperatures of the passive TPS. Maybe the heated fluid could even aid reaction control by funnelling the exhaust? I suppose active cooling is just another form of ablation TPS only with more control (and reusability!).

Posted by Brad at May 3, 2005 08:14 PM

Brad:

Good catch on the Martin design. However, the eerie similarities do not end there! Compare and contrast the LMCEV with von Braun's 1958 Luna-Earth Return Vehicle (LERV) -- that's right, the vehicle from the Army's 1959 Project Horizon moonbase program proposal!

I also noted that according to Mark Wade the LockMart CEV has a mass of 18,000 lbs. That's the same mass as the advanced (4-man) DynaSoar. Curiouser and curiouser!

Posted by B-Chan at May 3, 2005 08:16 PM

Dumb question maybe but, could this be launched on a Shuttle-B? I've heard speculation that NASA might want to have an unmanned heavy lifter with the option of carrying crews as well. Wouldn't the problem with the lifting body be mute on a side mounted Shuttle-B?

Posted by Shawn at May 3, 2005 08:51 PM

Brad: one thing active cooling (transpiration cooling, probably) could get you would be the ability to cool the vehicle using materials mined in space, such as water. That's easier to do than fabricating solid ablators from ET materials. Not clear what this buys you for launch to LEO, though, since the vehicle needs to be able to survive high speed abort scenarios.

Posted by Paul Dietz at May 4, 2005 08:31 AM

Lots of good comments. I can respond to a few points raised.

Even though Soyuz is a capsule, it is able to limit the entry g's from LEO to 3 or 4 when it uses a guided entry. A few months after Columbia a Soyuz came back from the space station and suffered a software failure, resulting in an unguided (aka, pseudo ballistic) entry. It pulled 8g that time, the crew had a rough ride and they landed hundreds of kilometers off target. Some of the Apollo capsule entries were from LEO and they pulled around 3g too, they hit 6g or more only when coming back from the moon.

Even if we use parachutes, a guided entry (even with a capsule) allows you to deploy your parachutes pretty close to where you want to. In fact, during the Apollo days I think the farthest 'miss' distance at splashdown was 5 nmi. That's good enough to land in the ocean near a coastline, or in a wide open plain or desert.

Wings with leading edges are fine for entry from LEO, but the heat rates on a leading edge during an entry from lunar or mars return are VERY high due to the significantly higher entry speeds. I haven't heard of a TPS material that comes close to handling that. As such, I'm skeptical that a winged crew vehicle can be used for missions beyond LEO -- blunt bodies have lower heat rates.

Posted by Gavin Mendeck at May 4, 2005 12:18 PM

Gavin: (on sharp body leading edges) Perhaps *that* is where active cooling could be applied? The heat rate there is certainly very high, but it's rather localized.

Posted by Paul Dietz at May 4, 2005 12:43 PM

Gavin: yes, you can land pretty predictably with a capsule and even pick your place along a path by timing the deorbit burn but more lift still gives you more freedom to actually choose the target, besides accuracy, and you don't need to wait n orbits etc...

I don't know if this LM CEV has a flyable parawing, but if it has, then I guess it'd be as accurate as the space shuttle, maybe even easier in the latter parts since it wouldn't "fly like a brick".

Of course, that doesn't say a classic capsule can't have a flyable parawing too.

This whole design can also be seen as a very high-lift capsule. It's coming down on parachutes anyway, so in that way, it's closer to a capsule than to a shuttle.

The "wings" are also so thick that there isn't any super-fancy technology required for the leading edges.

What's roughly the difference between return from Mars vs return from Luna re-entry speedwise? What about accuracy?
That makes you design to avoid g-forces a lot more than you would just for LEO. Then you could have almost the same vehicle for LEO as well as the final re-entry craft for the crew returning from Mars.

Posted by meiza at May 4, 2005 03:55 PM

> Even if we use parachutes, a guided entry (even with a capsule) allows you to deploy your
> parachutes pretty close to where you want to. In fact, during the Apollo days I think the farthest
> 'miss' distance at splashdown was 5 nmi.

Based on fewer than two dozen Apollo flights. As you state, Soyuz has landed hundreds of kilometers off course.

What happens if a capsule targetting "a wide open plain or desert" comes down that far off course? What happens if it comes down in LA instead of Edwards AFB?

What exactly is the attraction of expendable rockets and capsules? It's certainly not that they are cheap to develop. Mike Griffin has said that CEV alone will cost $15 billion. Even the hugely overengineered 2nd Generation RLV was estimated at only $5-6 billion.

Is it nostalgia for the old days? Fear of change? What?

Posted by Edward Wright at May 4, 2005 10:46 PM

I found some data on the entry interface velocity for trans lunar vs. orbital reentries.

Basically, it works out to be close to the actual velocity of the spacecraft in transit prior to entry.

for orbital entries, around 7863 m/sec (Apollo 7,9)
for lunar entries, approx. 11064 m/sec (Apollo 8)

I also noticed that the transfer velocity that needs to be killed on a Mars->Earth Hohmann trajectory is around 3000 m/second. Which would mean the delta-v relative to the *Earth* would likely be lower for the Mars mission. There is the term of the Earth's *orbital* velocity though. (If you came in "from behind" the Earth, you would be "overtaking" the earth at 3000m/sec. or more for a faster trajectory (the Hohmann trajectory takes ~250 days to transit from Mars to Earth, you'll probably want to do it in half that time).

The closing velocity with Earth (when far away from the earth) will be 3000 m/second, say, which is pretty similar to the delta-v applied by the TEI burn in the Apollo spacecraft (~3200 m/second). (so a the "top" of the gravity well, ie. the moon, the apollo spacecraft was closing on the earth at 3200 m/sec more or less. By atmospheric interface, it had accellerated to 11K m/second.

So using that, i would think the return direct from mars would be *similar* to a return from the moon. Maybe a little faster (becuase there is more gravity well "above" the moon that your hypothetical Mars craft will traverse, so its closing velocity at lunar altitude might exceed the Apollo's).

However it probably wont be *much* higher if it is. Maybe 1000-2000 m/second?

A typical design criteria for Earth entry is no MORE than about 15000 m/second. The heating rates just get too wild if you go above that.

Which argues for a longer term reentry, like an aerocapture trajectory. (they didnt know how to do that back in Apollo days, nor have the materials for it, but now we do).

The G's get pretty intense for higher speed atmospheric entries (because you're slowing down in about the same amount of atmosphere, you just do it faster if you start off faster). Your lower atmosphere velocity needs to be pretty much the same, and is limited to a small Mach number.

Posted by Joe Pistritto at May 4, 2005 11:14 PM

The lunar Soyuz variant, Zond 7, made a "skipping" re-entry (not sure what that is exactly), dipping in the first entry over the south pole for landing in Soviet territory. Two were succesfully flown around the moon unmanned. Zond 8 entered over the north pole and could be tracked for flight path adjustments since it overflew Soviet territory, and it landed quite accurately in the Indian ocean.

This technique can be refined with today's technology... and with more lift, you might make it easier.

I wonder what's the aerocapture L/D & heat shield requirement for a fast mars->earth trajectory. That way, you could save the whole spacecraft assembly for reuse. For a re-entry vehicle something aerocapturish might work and it's probably a bit different than a real aerocapture into orbit.
I know the current Mars orbiters have used aerobraking to slowly circularize the orbit and still needed hefty insertion burns. Is aerocapture mainly a guidance problem? Would it be actually easier to do that on earth?
It's not been demonstrated fully yet anyway.

Posted by meiza at May 5, 2005 05:38 AM

Paul: You're right, active cooling might help for the leading edges.

Edward: You brought up a good point about what if CEV lands in the wrong place. I'm pretty sure public safety for launch _and_ entry will be considered from the start in the design of future vehicles, including CEV. Columbia has ensured that. I think capsules seem to be popular because they're simpler in design and should therefore be more reliable. (Ideally that should translate to lower costs too...)

Joe and meiza: Apollo actually had an entry skipout capability too, although they never used it. They designed it in because they needed to be able to avoid bad weather at and near the primary 'landing' site. Apollo 11 actually did have to redesignate its landing site due to forecasted weather, but it didn't require a skipout... they only shifted the target site a couple of hundred miles downrange.

Earth aerocapture is possible with L/D as low as a capsule. I don't remember if the heating is much less. I'm sure there are AIAA papers on the subject. Earth aerocapture is nice because we have a nice, thick and dependable atmosphere. The Mars atmosphere is much thinner and also varies much more due to solar heating, dust storms, etc. Aerocapture is still possible there, you just have to be more careful. I don't think aerocapture guidance is a problem, it's more that no one has actually done it yet so it's harder to find a manager willing to try it if there are other options.

Posted by Gavin Mendeck at May 5, 2005 07:31 AM

The more I look at it the more it seems as if the atmospheric stuff is just in case of an emergency and that perhaps it's not meant to go up and down as part of its standard mission plan. If I'm reading that correctly then I don't have any real problems with the design.

Posted by rjschwarz at May 5, 2005 08:33 AM

" Wouldn't the problem with the lifting body be mute on a side mounted Shuttle-B?"

MOOT, not mute.

Posted by Mr. 6th Grade Vocabulary Minimum at May 5, 2005 06:24 PM

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