As promised, NASA issued the formal invitation on Tuesday for a competition leading to new types of commercial spaceships that could carry astronauts to and from the International Space Station.
Three of the invitees have a multimillion-dollar head start.
NASA expects the final phase of the competition — known as the Commercial Crew Transport Capability program, or CCtCAP — to result in a fleet of commercial spacecraft that are certified to transport crew by 2017. The space agency would prefer to have more than one provider for those transport services, but that might depend on how much funding is available.
The timetable and resources available for commercial spaceships are key sticking points that are left unresolved in Tuesday's request for proposals. Last week, NASA Administrator Charles Bolden called on Congress to provide the full $821 million requested for the current fiscal year "to keep us on track to begin these launches in 2017." Congress, however, has proposed spending hundreds of millions of dollars less.
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