Lockheed Martin unveils Space Shuttle replacement

Vegan Bob writes "Lockheed Martin released its proposal for the Crew Exploration Vehicle (CEV) in a recent Popular Mechanics article. NASA will choose this vehicle scematic or opt for the yet-released Northrop Grumman design in 2008. The CEV will replace the Space Shuttle program, and will eventually go to the moon (between 2015 and 2020)."

Comments

Re:One or two questions related to these articles:

[Rei]

If you read TFA, you have a wild imagination to see some of the things in there that you claimed were in there. But to answer your questions specifically:

Why add an orbital rendezvous requirement to all missions?

We don't use the Shuttle for all missions, and the Russians don't use Soyuz for all missions. If we don't need humans or a rendezvou, we use Delta and Atlas rockets. You build to the mission, and this is built to the mission.

Why use a shape like this which, I presume, requires the use of failure-prone ceramic tiles for reentry protection

It says no such thing. In fact, from a reentry standpoint, this craft looks like what the shuttle was *supposed* to be, but wasn't because of budget constraints. It uses a titanium frame - this allows it to run hot on reentry, which means that heat dissipation issues aren't as serious, and damage isn't as threatening. A side advantage is you'll get a far better payload ratio.

With a titanium frame, you generally only need to protect your leading edges, and they're using RCC, which is the best material out there in the present-day for such extremes (and isn't tiles). It's expensive, but it's a one-time production run, barring damage.

Titanium frames also fatigue a *lot* less. In short, you get a safer, much lower maintainence, and longer lifespan craft. The only downside is higher initial cost.

instead of a tried-and-proven heat sheild

RCC is a tried and true heat shield. If you mean "ablatives", don't delude yourself into thinking that they're cheap, either - this will be far cheaper than ablatives when amortized over a few flights. Ablatives are costly and tricky to apply properly (just like other spray-on things, such as foam insulation) - and are very difficult to use around moving parts.

when you're planning to use parachutes to land the thing anyhow?

Parachutes don't slow you from orbital velocity. You might have noticed, if you had read, that it has wings. Do you know why? It's not to meet Buck Rogers Stylistic Guidelines(tm) - wings let you skim the atmosphere longer on reentry, burning off your heat slower. Then, on this craft, a drogue chute will fire, followed by the main chute. It's the best of both worlds - the wings can be smaller and optimized for hypersonic flight only, while they still give you a gentler reentry profile.

it's not necessarily reusable?

What cave are you living in that you didn't learn that the CEV was to be a reusable vehicle? The *launch vehicle* isn't expendible - it will probably be a modified Atlas or Delta, which are very good launch systems. Sure, I'd love to see a fully reusable booster that doesn't cost a fortune (which, by all means, should be possible), but one thing at a time.

Overall, this is a great looking craft, and it will benefit greatly from all of the research that went on from the Shuttle program (and there was a *lot* - cost-reduction and safety-enhancing research was a good portion of the Shuttle's budget). My only real question is that its hypersonic drag profile looks a bit odd. Namely, there's no visible pinch as the wings widen (drag at hypersonic velocities is largely proportional to the maximum cross sectional area, so you typically pinch the fuselage as the wings eat up more cross section). I guess I'd also like to know why they chose ethanol biprop propulsion over, say, kerosene or LOX/propane. Still, great basic design principles on this craft.