NASA's Constellation Program is making progress toward selecting a prime contractor to design, develop and build the Crew Exploration Vehicle (CEV), America's first new human spacecraft in 30 years.

The agency has issued Phase II of a Request for Proposals. It is a "Call for Improvements" that incorporates the results of additional analysis and study. Phase II adds detailed design, development and production requirements. Phase II proposals will be evaluated and used to select a single CEV contractor later this year. For RFP details,