Thomas James has analyzed the Level 1 requirements for the Orbital Space Plane that NASA released this week, sparing me from having to do so.

Could all these seemingly modest goals suggest that maybe they'll be looking to do lighter, cheaper systems which can be built in greater numbers?

There would be a lot to be said for such an approach. I don't like their timeline, but the specs look like they may have more potential than you're crediting.

Lighter, cheaper than what? It's still insanely expensive for the capability.

Why is it that the development of ALL other technologies is moving exponentially faster than in lets say 1962, except at NASA. NASA wants to drag this OSP pig out to a 20 or 30 year project. Not to mention not hardly looking towards Mars at all. How, why?

I worked in technology, in one way or another, for 20 years and I cannot think of one thing that I ever worked on or around that took that much time to develop. We are not building our next level space vehicle from the ground up. We've done this before. We have more alloys, faster computers, lighter and stronger everything than we did when the Shuttle Fleet was designed.

So if we have all this to draw from now, where does NASA find all the difficulty building the next vehicle? Where would a government monopoly find that much difficulty? The government monopoly doesn't make the vehicle it contracts that out. Its sets the goals and it sets parameters and sets policy. Where would all that difficulty come from?

Certainly a government monopoly would not have some sort of entrenched bureaucratic system of thought that would cause this much difficulty. Where would the difficulty come from? We may never know.

Posted by Steve at February

I have to say the time table bothers me more than a little. Given the pressure on NASA and the Government in general to do something, why reinvent the wheel? Wasn?t there an option to launch the X-38 on an ELV and possibly adapt it for other missions? Last I heard they were working on the version to test from orbit. Why start from scratch?

The question I'm hearing is: "NASA has been working SLI for two+ years, and STAS, etc., for years before that...and this is the set of requirements they come up with?"

Doesn't seem to be much in this document to show for all that effort...this is the kind of thing I would have expected to see at the *beginning* of SLI.

But then, does it matter what requirements you levy on a vehicle that will never get built?

On the bright side, by the time NASA has the OSP ready, the private sector might very well have an interplanetary spacecraft on the market for $9,995.00

Long, expensive, open-ended programs = job security and lots of pork for the home boys.

Purely for my own amusement, I've been following up (from a non-engineering perspective) something mentioned by Mr. James in his commentary, in which he wondered whether there were any of the requirements except for crew capacity that couldn't be met by a resurrected Apollo CSM. Here's what I've come up with, comments and criticisms welcome:

1) Rescue and evacuation capability for 4+ ISS crew members, with the wearing of suits possible but not necessary.

Got that covered. There was a design study (http://www.astronautix.com/craft/apouecsm.htm) that demonstrated the capability of an Apollo CSM to carry up to five astronauts in an emergency situation. I believe one CSM was actually outfitted for this during the Skylab 3 mission. Suits are possible but not needed in an Apollo, and there were uprated couches designed for Apollo 7 that allowed the astronauts to survive a land "thump-down" if needed- should be plenty of support.

2) Rapid seperation from ISS in an emergency.

This is the only iffy one- the undocking doesn't take that long on an Apollo, but I can't seem to find any information on how long powering one up took. Anyone know how long it took for the Skylab missions?

3) 95%+ availability, with a loss of crew probabliity lower than a Soyuz. For crew transport, risk of crew loss lower than the Shuttle

Apollo made this easily (I believe) on its missions, although I certainly could be wrong. There were definately fewer astronuats killed in Apollo than cosmonauts in Soyuz. With regards to the shuttle, the addition of the LES alone would make the risk of crew loss much lower, not to mention that the heat shield is all one piece and therefore cannot lose tiles.

4) Ready by 2012, and minimum life cycle cost, with less time to prep and launch than shuttle.

This is the other weak point...I'm not sure how Apollo/Saturn IB stacks against Shuttle here. It could hardly be more, although with a total of only 40 flights anything's going to be expensive. Of course "minimum cost" isn't a terribly meaningful term anyway.

5) Increased on-orbit manueverability compared to shuttle.

One word: SPS. An engine with TEI capability should be able to do at least one orbital change manuever. Unfortunately, as I have said, I'm not an engineer and don't know much about orbital mechanics- would someone with more expertise care to comment?

6) Launch on an ELV

Yeah, it does that.

7) Contingency capability for cargo/science delivery to the ISS

If you don't mind some EVA work, the SIM bay that was in the SM of the Apollo 15 and later CSMs should do just fine. Plenty of room in there IIRC

8) Able to dock with the ISS and support a 4-6 month stay in space.

Change the docking adaptor and make sure that your systems don't degrade (which should be less of a problem than Soyuz since you're using fuel cells), and you're there.

None of this is to suggest that we should go back to Apollo, but isn't it a little sad that NASA is essentially ordering up a vehicle that performs to a standard we had thirty years ago, and adds nothing new? (other than reusability, which is meaningless without a high flight rate)

Jeff, your last point is spot-on what I meant by the Apollo CM reference.

The problem with resurrecting an Apollo-style vehicle is that the reentry is basically ballistic... and that means high accelerations. This presents problems with the requirement of "the safe return of deconditioned, ill or injured crewmembers".

That's one (but only one) of the reasons why the Orbiter was winged: it minimized reentry loads. You could accomplish the same thing with a lifting-body vehicle (hence the X-38 design), but it's going to be hard to do with a capsule design.

Of course, one might reasonably argue that getting them back (but beat up) is better than not getting them back at all...