The Future of Flight?

Popular Mechanics ^ | Published in the June, 2005 issue | DAVIN COBURN

[Cincinatus]

May 3, 12:00 am--When NASA requested designs for a Crew Exploration Vehicle (CEV), two major teams--one headed by Lockheed Martin and one by Northrop Grumman and Boeing--took on the challenge. The winning concept will be chosen in 2008, and the manned vehicle flown in 2014.

The agency's primary requirement is to "ensure crew safety through all mission phases." The Lockheed team--consisting of six companies--came up with a CEV in three parts. The titanium crew module holds four to six astronauts and launches separately from the mission module and the propulsion stage. They rendezvous in orbit to create a 70-ft.-long vehicle that weighs just under 40 metric tons.

INSIDE THE CREW MODULE
1 Nitrous-oxide mono-propulsion system
2 Float bags
3 Micro-Meteoroid and Orbital Debris protection shield
4 Liquid oxygen long-term storage
5 Supersonic drogue chutes
6 Fuel cell

The team scrapped foam insulation in favor of a redundant Thermal Protection System that includes a backed-up carbon-carbon heat shield. In an emergency, a rescue module designed into the top 22 ft. of the crew module can be fired off at any time. The CEV is not designed to glide upon re-entry like the shuttle; rather, it will be equipped with parachutes and airbags to set down on land or water. Interchangeable computer systems will increase adaptability between modules.

The most anticipated--if least glamorous--advancements will include a means to generate power for long-duration stays in space and a diagnostic safety system to troubleshoot problems. Says Pat McKenzie, business development manager for Lockheed's CEV program, "Simply getting to space shouldn't be the exciting part."

[Cincinatus]

Scoop du jour -- LockMart's version of the new American space vehicle, the Crew Exploraiton Vehicle (CEV). Hmmm.... Dyna-Soar, anyone?

[Names Ash Housewares]

Wow! I was not expecting wings again.
She looks like the ship in Planet of the Apes!

[Cincinatus]

Ping FYI, sweetie!

[Cincinatus]

Please ping to the Space list

[Mr. Jazzy]

Dyna-Soar it is!!!

It just needs the landing skids!

[Captain Rhino]

Yeah, that's what I was thinking.

Weren't there also proposals in the original Space Shuttle program for a shuttle-atop-booster configuration? I know it makes the stack pretty tall, but it would essentially negate the debris impact problem that is currently inhibiting the Space Shuttle's return to flight.

[Cincinatus]

Weren't there also proposals in the original Space Shuttle program for a shuttle-atop-booster configuration?

Yes, there were, but it was a much smaller vehicle than the Shuttle turned out to be. It was principally to be used for ferrying people to and from LEO and presupposed a separate cargo vehicle, very similar conceptually to what's being planned now. STS as it ended up was both combined into one vehicle.

[r9etb]

The Lockheed team--consisting of six companies--came up with a CEV in three parts. The titanium crew module holds four to six astronauts and launches separately from the mission module and the propulsion stage. They rendezvous in orbit to create a 70-ft.-long vehicle that weighs just under 40 metric tons.

I can see the design trades tha led to this, but two rendezvouses just to get moving? Every mission? That's at least two, and maybe three launches per mission ... sounds pretty expensive to me.

[mikegi]

Why have wings/winglets if the ship isn't going to be a glider? Wouldn't a simple capsule be better? I like the idea of separating the crew transport from the cargo transport. The Shuttle never made sense to me in this regard.

[Cincinatus]

One rendezvous, I think. They seem to assume using EELVs as the launch vehicle, probably Atlas V, considering that this is LockMart. One could easily do this on a single heavy-lift launcher, Shuttle-derived or other.

The 40 mT number seems a bit low to me. I guess that's just for a "Block 1" version of the CEV that just does LEO missions. You would need separate lunar and propoulsion modules to do the Moon mission.

[grayforkbeard]

Looks like they have come full circle back to the original concept for a simple reusable winged vehicle. That was before everybody and their dog jumped in with all manner of requirements that resulted in the current shuttle design. If the military gets their fingers on it, it will no doubt turn into another dog and pony show and grow into another monster designed in committee.

Now if they can just find a use for it?

[Cincinatus]

An interesting discussion of this piece at Rand Simberg's blog, Transterrestrial Musings:

May 02, 2005
Category: Space

A Peek At The Future?

......

The biggest obvious difference between it and the Boeing concept (at least the Boeing concept that has been on display in the exploration studies--I can't speak to what was actually proposed) is that it's got wings. Or at least a body with a lot more lift than a capsule, with supersonic drogues. Despite that, it still lands with chutes and bags, so it's not clear why they want such a high L/D, except for more cross range and landing site flexibility, and reduced entry gees. What NASA has been calling a Service Module they seem to be calling a Propulsion Stage. It's not clear whether it also contains life support consumables (as the Apollo Service Module did), though it does mention that the crew module itself has a LOX supply and fuel cells.

It definitely looks more sexy than Boeing's design--they may be hoping that will help them as it did in X-33, 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.

Posted by Rand Simberg at 04:52 PM | Comments (22) | TrackBack (2) Technorati Links

Go to the link and click on "Comments" for a pop-up window with the discussion.

[r9etb]

One rendezvous if the propulsion module and mission module are launched as a package. Note, BTW, that unless the mission module can be reconfigured, it will have to be treated as expendable. Likewise, the propulsion module looks to be expendable unless it can be refueled. However, if it has to be refueled, that either means a separate refueling mission, or you have to carry the fuel up on the crew module ... in which case, why not just buy off on putting the (relatively light) thrusters on the crew vehicle as well?

As I said: I can see the trades that went into this, but I really don't think this concept works very well from an operational/sustainment perspective.

[Cincinatus]

As I said: I can see the trades that went into this, but I really don't think this concept works very well from an operational/sustainment perspective.

Possibly. However, I think that reusability is vastly overrated as a desirable quality in space systems engineering. In the case of Shuttle, it led to building a system in which you have to lug over 200 tonnes of dead weight up to LEO and back with each flight. A modular system, designed for quick changeout, refurbishment, and reflight, would probably serve our needs better than complete reusability.

In my mind, "sustainable" really means the political will to sustain a long term space mission. And I think that depends more on mission payback (scientific, technical, security, or economic) than it does making space flight "cheaper."

[r9etb]

The problem is, though, that by adding expandables and at least one extra launch for each mission, you've probably done away with any cost savings -- you may actually end up adding net cost. The only advantage is if you can keep re-using the non-crew modules once they're on-orbit -- but then the design trades don't look so good.

I think the real cost and difficulty has to do with the way you come home. The Shuttle was designed to come home like an airplane, which is what drove most of its design, weight, and complexity.

What if you designed a system that was somewhat more "Apollo-like?" Perhaps a bolt-on expendable ablative re-entry shield, coupled with a reusable crew/mission module, and some sort of parachute system at the end. I know they've tested such things.

[nuke rocketeer]

'cept it don't soar! Back to the future. And it takes two or three launches to get one crew in orbit.

[Renegade]

I was thinking the same thing ( DYNA-SOAR ) I have a couple of lithographs from 1962 showing the launch of the vehicle and another of the re-entry phase .The booster looked like a Gemini booster with fins attached .

[Young Werther]

..and of course there are the mid deck storage bins. NASA has that item engineered and operational.

The Venture Star was the way to go with the aerospike engine providing a positive push to orbit. That engine has the thrust without the plumbing and gimbaling of a standard bell shaped rocket engine. Therefore, thrust to weight is maximized. But heck.....

[mikegi]

Thanks for the link. I guess the capsule approach does have some supporters. I remember back during the Columbia disaster someone posting that we should use capsules and it seemed so obvious to me.

Also, I read the "Chariots of Apollo" story out on the NASA website and really became a proponent of a very simple lunar lander like the "Buck Rogers" one designed in 1961. Here's a link:

http://www.hq.nasa.gov/office/pao/History/SP-4205/ch3-5.html

Looks (relatively) inexpensive and I could see several of those landers hanging off of a Moon space station. The crew links up with the station and uses the simple landers to travel to and from the Moon.

Of course, I'm a complete amateur when it comes to space missions so the idea may not make any sense in reality :)

Mike

[JeffersonRepublic.com]

I would like to see the Delta Clipper
redesigned and put on the table.
It could land on mars, moon or
back on earth.

NASA crash it in 1995, they
should rebuild it at least.