Chair Force Engineer

Thursday, January 14, 2010

Back to Mars, the Battlestar Galactica Way

Courtesy of Scott Lowther, I recently checked out a recent study of an "austere mission to Mars" conducted by personnel at JPL and The Aerospace Corporation. Space fanatics should definitely check it out.

Studies of human missions to Mars always fascinate me, even if many of them are incredibly impractical. A few years back I took a look at a similar study to the current "austere" study that was conducted by SpaceWorks Engineering. Both studies made use of multiple Ares rockets to assemble the spacecraft, in an approach that Bob Zubrin derisively calls "Battlestar Galactica."

While JPL+Aerospace Corp (and previously SpaceWorks Engineering) spun their study as evidence that a human mission to Mars is feasible, I take a very different view. A manned Mars mission is feasible but expensive, lengthy and impractical without adopting nuclear propulsion (either nuclear-thermal or nuclear-electric) and in-situ resource utilization. The development pricetag for this "austere" four-crew mission is fairly low compared to the SpaceWorks estimate at around $75 billion for an all-US program, and $63 billion for an international one. Each mission would require twelve Ares V launches to assemble, plus one Ares I for crew launch. (Compare this to the nuclear-thermal Boeing IMIS plan from 1968, which used six uprated Saturn V's plus two Saturn 1B's for crewed launches.)

The austere study uses some innovative approaches to solving the mission's technical challenges. Crew habitation on-orbit is similar to the ISS "Zvezda" module. The Mars Orbit Insertion module performs a relatively short burn at Mars arrival to put the spacecrafdt into a highly elliptical orbit, which is circularized by aerobraking. (This seems to be a compromise between a fuel-intensive capture into circular orbit, and a risky orbit insertion that purely involves aerobraking.) The Mars landers rely on rockets only to decelerate and land on the Red Planet, with no assistance from parachutes (which is probably for the best, given the reduced effectiveness of parachutes in Mars's thin atmosphere.) One concern of mine regards the Orion heat shield. With its heat shield exposed to the extreme heat and cold of space on a multi-year mission, I wonder how well Orion would hold up during re-entry.

Like Scott Lowther, I'm also disappointed at the way PowerPoint has killed the lavish aviation art we used to see from the big aerospace companies. The "scale" model in the presentation is hokey, bordering on ridiculous. It's clearly a bash of the Revell Mir Space Station kit with a toy Saturn V. There's no excuse why the model builder couldn't have used the much more realistic (and widely available) Revell-Monogram Saturn V kit for the model. And apparently we're to ignore the scale of the CEV, since the Apollo command module was used to represent the much bigger Orion CEV.