By James Dean, Florida Today
CAPE CANAVERAL, Fla. -- SpaceX has the cheapest plan for developing a commercial space taxi, while The Boeing Co. has the strongest technical approach, according to a NASA evaluation of their proposals.
Sierra Nevada Corp.'s mini-shuttle offers a promising alternative to the two capsules but must overcome the most technical challenges, NASA determined.
In a 13-page report released recently, the agency explained why it awarded those three firms up to $1.1 billion to complete designs of private rockets and spacecraft that could fly astronauts to the International Space Station by 2017.
"In short, Boeing and SpaceX had the best proposals, followed by SNC," wrote Bill Gerstenmaier, head of NASA's human space program, who signed off on the selections July 31.
NASA announced Aug. 3 that it had awarded Boeing $460 million, SpaceX $440 million and Sierra Nevada $212.5 million for work to be performed through May 2014.
ATK, the only other firm considered from a pool of seven applicants, made the weakest proposal technically and received no funding.
"The proposal lacked enough detail to determine if a safe crew transportation system could be developed in a timely and cost-effective manner out of the heritage components ATK selected for this concept," Gerstenmaier wrote.
An evaluation panel found SpaceX's technical plan also lacked detail, warranting only a "medium" confidence rating. But Gerstenmaier said the company's experience flying cargo to the International Space Station under a NASA contract would give it an advantage when upgrading its Falcon 9 rocket and Dragon capsule for crewed flight.
Gerstenmaier credited Boeing for a comprehensive, step-by-step design approach that effectively integrates heritage subsystems into its CST-100 capsule, while noting that the company had proposed the least private investment.
NASA has not disclosed how much each company plans to invest in the development effort, but said "Boeing as a corporation contributed less to this activity than any offeror."
Sierra Nevada received "medium" confidence ratings for both its business case and technical approach. Gerstenmaier said the greater design complexity of its winged Dream Chaser presented "significant risks" -- including its heat shield, weight, abort capabilities and use of non-toxic propellants -- that could impact costs.
At the same time, the vehicle would give crews and sensitive cargo a gentler ride through the atmosphere and softer landing that could help attract more customers.
NASA did not have enough funding to make major awards to three companies. So Gerstenmaier weighed whether a smaller award for Sierra Nevada would limit the other two companies' progress. He decided that keeping a third option in play preserved a potentially valuable capability and supported a more open competition in case Boeing or SpaceX encountered a significant setback.
The approach, he said, "allows for the development of fundamentally different concepts with distinct advantages in a cost-effective manner."