WASHINGTON — With the House Appropriations commerce, justice, science subcommittee poised to take up NASA’s 2014 budget request July 10, a new report from the NASA Office of the Inspector General (OIG) highlights why the agency has been fighting year after year to win full funding for its Commercial Crew Program.

The July 8 report, “NASA’s Efforts To Maximize Research on the International Space Station,” notes that once any one of the three private space taxis now under development finally enters service, NASA and its partners stand to nearly double the amount of crew time devoted to research.

The space station’s six-person crew manages to devote an average of 35 hours per week to scientific investigations. Although the space station is capable of supporting a seven member crew, the orbital outpost is limited to a crew of six for as long as Russian Soyuz vehicles remain the only way to transport crew to and from the international space station (ISS). And those six crew members devote most of their waking hours to the necessary task of keeping the space station and their own bodies in working condition.

“The lack of crew transportation vehicles other than the Soyuz limits the amount of research that can be conducted on the ISS,” the OIG report says. “Although the Station is capable of supporting a seven-member crew, each Soyuz has a three-person capacity and only two Soyuz vehicles can be docked at the ISS at one time. This means that only six crew members can safely be aboard the ISS at a time to allow for evacuation in case of an emergency.”

Through its Commercial Crew Program, NASA is subsidizing development of competing capsule systems offered by Boeing and Space Exploration Technologies Corp., and a lifting-body design offered by Sierra Nevada Corp. All three crew transportation systems are designed to transport a minimum of four astronauts.

“Accordingly, once one of these vehicles is operational the ISS can be staffed with its full complement of seven,” the OIG report points out. “According to the ISS Program Office, a seventh astronaut could increase crew time devoted to research by more than 33 hours per week – a 94 percent increase over current rates.”

NASA is asking Congress for $821.4 million for the Commercial Crew Program for 2014. While that’s lower than the $850 million NASA sought for the program for 2012 and 2013, Congress has proven unwilling to fully fund the program, approving only $406 million for 2012 and $489 million for 2013.

“If this trend continues in the future,” the OIG notes in its report, “NASA likely will not meet its goal of having at least one vehicle transporting crew to the ISS in 2017.

“In that case, NASA would have to purchase additional seats on Soyuz vehicles. Soyuz manufacturing and assembly requirements require NASA to procure Soyuz seats at least three years in advance to avoid a gap in ISS crew transportation.”

NASA recently agreed to pay Russia $71 million per seat for Soyuz rides to and from the space station. That’s a greater than three-fold increase since 2006 when NASA was paying $22 million a seat.

The rest of the OIG report can be read here.

Brian Berger is editor in chief of SpaceNews.com and the SpaceNews magazine. He joined SpaceNews.com in 1998, spending his first decade with the publication covering NASA. His reporting on the 2003 Space Shuttle Columbia accident was...