Chair Force Engineer

Friday, June 12, 2009

Shuttle-Derived Fratricide

Rocketman, in his uniquely-unforgettable style, is taking a look at the race to replace Ares I. He thinks the writing is on the wall for the current Ares I, but continues to hint at a return to the original "Shaft" from the ESAS report using a stock SRB and an air-start Space Shuttle Main Engine on stage 2. At the same time, he thinks that the proponents of Ares, DIRECT and Shuttle-C are taking aim at each other, with the taxpayers getting caught in the crossfire.

After reading the presentation on DIRECT 3.0 from the International Space Development Conference, I can't help but agree with Rocketman. I must first congratulate the DIRECT team for pulling out all the stops to present their concept as a more sensible alternative to NASA’s technically-challenged and budgetarily-bloated plans for Ares I & V. The presentation is incredibly slick, and it’s the best apples-to-apples comparison between the two plans to date.

But near the end of the slides is an unnecessary slap in the face of Shuttle-C, trying to fend off competition from the easiest shuttle-derived option of all. I find their arguments to be a bit of a strawman, because even the most ardent Shuttle-C supporters do not see Shuttle-C as a crew launcher (they often leave that task to EELV’s.) And there’s no reason that Shuttle-C couldn’t be adapted to the clean-pad concept that DIRECT touts for their vehicle.

I have to confess some sympathy towards Shuttle-C or a similar design (perhaps using stock RS-68's instead of SSME's.) It would be the cheapest shuttle-derived rocket of all, at least from a development budget standpoint. But it doesn't offer a lot of room for future evolution, and it inherits the same inefficiencies that are ingrained into any shuttle-derived rocket.

Is the re-opening of the launcher debate good for the taxpayers? To some point I'd agree, because Ares I is a very expensive and a very behind-schedule vehicle that offers little benefit over the Delta IV Heavy (which has already been paid for.) The debate we're expecting from the Augustine Commission is one which should have been taken to the public in 2005. But there's also the risk posed by getting mired in continual debate and wasting taxpayer dollars on a succession of aborted development projects like Shuttle II, X-33, Space Launch Initiative, and Orbital Space Plane.

For both Shuttle-C and DIRECT, time is not on their side. The infrastructure of the shuttle program, particularly at the Michoud plant where the ET's are built, is being dismanted as the blue-ribbon panels busily debate. Unless the dismantling is halted, the panel may be left with no other choice than to put its rubber-stamp on "Plan Griffin." I would still argue for Delta IV Heavy as the fastest, cheapest and lowest-risk method for getting Orion into space. To retain the shuttle workforce, LC-39 could be converted for EELV use. One pad would go to the Delta crew launcher, while the other would be reserved for a future EELV variant capable of 55-tonne payloads (as per the Northrop-Grumman Crew Exploration & Refinement study of 2004.)

The Augustine Commission absolutely has to get this right. NASA has lost a lot of credibility with its string of past failures in developing manned launch systems, and it's hard to see how the agency can sustain a manned spaceflight program after another embarassing cancellation. It's not too late to change ships and abandon Ares, but the successor system cannot afford to be cancelled during its development.