Clark Lindsey points to a study (with which new NASA administrator Mike Griffin was heavily involved) that’s been kicking around for about a year now, apparently popular with some in the astronaut office, proposing an SRB-based crew launch system. Clark notes that “The reasoning is that this system could be developed more quickly than a CEV on a Delta IV or Atlas V since the SRBs are already ‘human-rated.'”

Well, not exactly. At least, they (correctly) don’t say that. As I’ve noted many times in the past, the phrase “human rated” is a very misleading one. What they actually say is that “…the SRM has proven to be the most reliable launch vehicle in the history of manned space flight, with no failures in 176 flights following the modifications implemented in the aftermath of the Challenger accident.”

The reality is that the SRB is not “human rated.” In fact (surprising to many) the Shuttle itself is not. “Human rated” or “man rated” is a phrase that so many misuse that I’d just like to purge it from our vocabulary, because as I’ve explained, it’s really a relic of the sixties. All we can say about the SRB is that it has flown reliably (at least after the O-ring problem was resolved) on our only vehicle that carries crew. As such, it may be the basis of a relatively (as expendable launchers go) safe ride for astronauts.

One thing that I never see mentioned in this concept, though, is how they propose to do roll control. The current SRB has none, because it is part of a larger vehicle, which rolls by gimbaling its nozzles. As a stand-alone system, it would have no roll authority at all, without adding fins or a reaction control system. Is that what those little appendages down at the bottom of the figure in Clark’s post are meant to represent?

In any event, such a vehicle will in fact be a new launch system (and one with a pretty rough ride and probably pretty high accelerations toward the end of the burn)–no one will be able to simply stick a capsule on top of an SRB.

[Update about noon eastern]

I just noticed another depressing little statement in the report: “During the time frame addressed by this report

Keith Cowing also wonders why NASA would want a missile defense analyst on a space exploration advisory committee. My reading of the VSE and the Aldridge Report is that the new vision should support several goals, one of which is defense, both national and planetary. It would in fact be quite useful to have someone from the space defense community involved in the planning, to keep an eye out for opportunities for synergism, and to bring a different perspective in the development of systems that could both help in that defense goals, and perhaps complicate them if done without consideration of those other strategic needs.

While it’s not obvious to me exactly how they would fit (other than for the planetary defense role), concern about how LEO activity will coexist with potential LEO missile defense systems is worth worrying about, and it’s not a bad idea to have someone on board who does think about such things for a living.

Keith Cowing wonders why NASA is procuring hardware for military tanks.

Well, without discounting the possibility (even likelihood) that there is something bureaucratically suspect going on here, there is a plausible justification, in that the technology for an oil-free turbine would be very handy for space applications (e.g., power conversion for nuclear systems), reducing maintenance and helping with reliability. Since the funding is from Glenn (NASA’s propulsion center), it makes sense that it would develop this potential dual-use technology. It may even have other civilian terrestrial spinoff applications.

It is strange that the applications cited are so military specific, though. Equally strange is that the application (a diesel environment) is so specific so as to make it look suspect as a pure technology development. We’re a long way off from space diesels.

Dale Amon has some interesting, and plausible, speculation about Richard Branson’s business plans for space transportation.

Sam, what I don’t understand about your proposal is, well, how it would actually work. The devil is always in the details in these things. When you say:

It would be private industry and individual citizens who could book whatever missions they wanted.

…what does that mean? What price will they get the service at? Who is purchasing from the launch providers?

My idea would be to have the government purchase some fixed (and large) quantity of various goods and space services (e.g., tickets to LEO, pounds to LEO, maybe even tickets and pounds to the lunar surface), use whatever there was a government need for, and auction the rest back on the market. If the market price turns out to be higher than the price paid by the government, then the program costs nothing at all (other than the cost of the services that the government needs). If it’s a lot more, presumably the providers would stop selling to the government (assuming they were allowed to opt out) and sell directly to the market. If the differential was low, then we’d have a subsidy, in which the cost of the program would be the difference in price between market and government cost of the service.

But in order to make this fly, the country (and its government) would have to decide that having large amounts of activities in space at reduced unit costs were sufficiently important to justify what would be considered a large expenditure in the context of current space activity (essentially doubling the NASA budget under your proposal, but I think you could do a lot of damage to the problem for a few billion a year). There’s been little sign of that so far.

Thomas James expresses a fear about government lunar bases, and NASA, that I share. We’ve got to break out of Apollo mode. I hope that the new administrator understands this, but so far, I see little sign of it.