NASA's spaceship development program enters its third phase by offering funding for firms to design and build space transport systems for ferrying astronauts to and from the International Space Station.

Known as the Commercial Crew Integrated Capability Initiative (CciCap), NASA will provide funding from $300 million and to $500 million to two U.S. firms selected under the new 21-month partnership agreements. Like the two earlier phases of the development program, the third phase will be governed by Space Act Agreements.

NASA called on companies to submit proposals by March 23 for the development of an integrated system, including a launch vehicle as well as a crew capsule, ground operation and mission control.

NASA plans to select at least two potential providers for "safe, reliable, and cost effective human access to space" and those winning the bids will need to develop an integrated system that includes both a crew vehicle and launch system.

Selected firms will have until May 2014 to complete the integrated designs for their transport system, and if funding allows, to proceed with orbital test flights by the middle of the decade, NASA said.

NASA is also funding a separate program known as Commercial Orbital Transportation Services to develop unmanned cargo craft for resupplying the space station in addition to CciCap.

In line with this program, SpaceX and Orbital Sciences are in line to receive a total of $684 million if they complete all the milestones in that program.

According to NASA, the U. S. Government is banking on private companies to build a new generation of spaceships. Since 2010, NASA has provided a total of $365.5 million to private companies for crew vehicle development.

These include $130.9 million to the Boeing Co., $125.6 million to Sierra Nevada Corp., $75 million to SpaceX and $25.7 million to Blue Origin. Smaller amounts have gone to Paragon Space Development and United Launch Alliance.
NASA is also in the midst of a multibillion-dollar effort aimed at producing crew vehicles and heavy-lift rockets for going beyond Earth orbit in the 2020s.

"President Obama is working hard to create an American economy built to last," NASA Administrator Charles Bolden said.

"NASA's support of commercial innovation to reach low Earth orbit is helping to support these efforts by spurring new technological development and creating jobs and economic benefits for years to come," Bolden said.