NASA has released a statement on the selection of three spacecraft companies to develop crew transportation to low Earth orbit (LEO), laying out the relative strengths and weaknesses of their proposals.

The selection announcement for the commercial crew integrated capability (CCiCap) development agreements came on 1 August after several months of speculation. Two full awards went to Boeing ($460 million) and SpaceX ($440 million), while Sierra Nevada won a half award ($212.5 million).

The proposals were divided up into technical and business cases and rated for effectiveness at meeting requirements and likelihood of confidence at meeting those goals.

Four credible bids were received for only two-and-a-half awards.

SpaceX, flying its Dragon capsule atop a Falcon 9 launch vehicle, initially received good marks for its technical and business approaches but was assessed at a low confidence of meeting CCiCap goals. After due diligence both categories were upgraded to excellent, and the level of confidence was upgraded.

 Sierra Nevada Dream Chaser CCDev

 ©Sierra Nevada Corporation

Boeing, using the CST-100 capsule and United Launch Alliance (ULA) Atlas V launcher, initially received a high technical and medium business mark which was assessed at medium confidence. After due diligence, the technical aspect was rerated to excellent with a high level of confidence, while the business case remained at medium but also received a high confidence level.

Sierra Nevada, with the Dream Chaser winged lifting body and ULA Atlas V, submitted a technical proposal at first deemed good but with a low confidence level, and a business plan deemed medium with a medium confidence. Upon due diligence, the technical proposal was upgraded to excellent with medium confidence and the business case good with a medium confidence.

ATK's bid with the yet-unbuilt Liberty launch vehicle and a composite capsule were initially rated low in both categories, and while the technical case was revised slightly upwards after due diligence, it remained the overall lowest-ranked proposal and was not selected.

Three proposals, by Space Operations, Aerospace America and Spacedesign Corporation, were disqualified for not meeting criteria, and were not considered.

Source: Flight International