Sierra Nevada Corp. drew the short straw in NASA's Commercial Crew Integrated Capability (CCiCap) competition, winning only about half as much of the federal seed money to advance its Dream Chaser lifting-body crew vehicle as its two competitors received for their capsule designs.
At $212.5 million, the company's award is not exactly chump change, but the $460 million for Boeing and the $440 million for SpaceX would go a lot further in wringing out the questions that remain about Sierra Nevada's unique approach to flying humans to space. The half-portion grew out of congressional fears that NASA was spending too much to preserve competition in its commercial crew development effort (AW&ST June 18, p. 26).
In his source-selection document William Gerstenmaier, associate administrator for human exploration and operations, says the Dream Chaser design—based on the old NASA HL-20 testbed—poses “significant risks because of design complexity.”
“The winged vehicle offers a lot of advantages, even to customers, in terms of easier landing—you can land on a runway—lower gs, cross-range from deorbit, that's all called out in the document,” Gerstenmaier says. “But associated with that are more technology hurdles. You've got to look at aborts. They're a little more difficult. You've got thermal protection issues, the heat-shield kind of stuff we dealt with on shuttle protection on orbit, all those things. So there's a lot more complexity with a winged vehicle.”
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