Chair Force Engineer

Saturday, September 09, 2006

A quick take on COTS

In order to sustain the space station when the shuttle retires in 2010, NASA absolutely needs the Commercial Orbital Transportation System to work out. Recently, two contracts worth a combined $500 million were awarded to SpaceX and Rocketplane-Kistler to develop COTS vehicles. I had a few thoughts about NASA's selection and what it means for the space station and private spaceflight.

The choice of SpaceX's Dragon represents the most conservative design (with the exception of Spacehab's approach, which would have used existing, expensive Delta & Atlas rockets.) It's a two-stage rocket (Falcon 9) with a semi-ballistic capsule on top. Contrary to my previous speculation, reentry occurs with the blunt end of the capsule facing forward. I like the simplicity of SpaceX's approach. The caveat is that while the design is safe and conservative, it's being built by a team that has yet to put a rocket into orbit. SpaceX deserves the chance to fix Falcon I and advance with their current plans, but NASA's schedule will probably not tolerate any further launch failures from SpaceX. A big firm like Boeing or LockMart could make the Dragon proposal work, but at great expense to the government. Hence, NASA wants to see the upstart succeed.

RpK's K-1 is the most conservative possible design for a reusable launch vehicle (unlike Falcon 9, which is reusable in a similar sense as the Shuttle SRB.) That being said, reusable will be inherently more complex than the expendible rockets. RpK is taking an opposite business approach to SpaceX: while SpaceX does a lot of in-house fabrication to save money, RpK is farming a lot of their work to established (read: too bloated for their own good) aerospace vendors like LockMart and Orbital Sciences. The K-1 is going to require significant funding in addition to COTS if it ever reaches completion.

It's in America's interest to see both vehicles succeed. While K-1 is an elegant solution to the space station resupply mission, it's clear that it won't be ready on NASA's schedule. In the short term, the priority should be placed on getting Dragon and Falcon 9 flying (which may explain why NASA gave more funding to SpaceX than RpK.) There's still a reasonable chance that SpaceX can get Dragon flying by the time the shuttle retires. That should minimize the length of time where the station has no down-mass capability, relying on expendible Progress and ATV freighters for support.