ISS Astronaut Testifies Before Congressional Panel From Orbit

NASA astronaut John Phillips briefed a congressional panel on the merits of the International Space Station (ISS) Tuesday while circling the Earth aboard the orbital research facility.

Phillips, science officer and flight engineer for ISS Expedition 11, is NASA's first astronaut to testify before a congressional committee from space. He joined two other space station veterans, Expedition 5 flight engineer Peggy Whitson and Expedition 9 flight engineer Michael Fincke, who spoke to committee members from the ground.

"Onboard the International Space Station, we are the experiment," Phillips said via satellite link from inside the station's U.S.-built Destiny laboratory. "We are trying to learn as much about human spaceflight as we can."

Phillips and his fellow astronauts spoke before members of the House Science Subcommittee on Space and Aeronautics. Of primary interest to committee members were the challenges faced by ISS astronauts, the space outpost's scientific payoffs and its role in the future human exploration once NASA's shuttle program retires in 2010.

"We can't be flying at $1 billion a flight and expect to keep flying a space shuttle," said Congressman and subcommittee member Dana Rohrabacher (R-California). "The costs have to be lowered."

Phillips told subcommittee members that the space station is about only half-built and awaits delivery of additional support trusses, pressurized nodes, modules and laboratories, each anticipating its turn to launch aboard a NASA space shuttle. Two new laboratories - Japan's Kibo module and Europe's Columbus module - still remain Earthbound, but could boost the number of ISS astronauts up to crews of six when finally delivered to the station, he added.

"Our experimental time is somewhat limited now," Phillips said. "[But] when there are six people aboard, there will be a lot more experimentation."

Previously, ISS crews and flight controllers depended on NASA space shuttles to deliver new station components and bulky replacement parts that are too large to ride aboard Russian Progress cargo vehicles. But NASA's shuttle fleet has been grounded since the 2003 loss of the space shuttle Columbia and its astronaut crew during reentry.

"One of the things brought home by the Columbia accident is that we need to stamp out complacency anywhere it exists," Phillips told the subcommittee. "[Spaceflight] is not like getting on an airliner, we strap ourselves on a rocket and there are some risks."

Dangers to astronaut health are among the spaceflight risks astronauts and flight controllers hope to better understand via ISS research, Fincke said.

"Aboard the space station, I lost a fair amount of bone mass, about six percent," Fincke said, adding that he managed to regain that lost bone mass after returning to Earth from his 187-day mission. "That's accelerated osteoporosis, and by understanding how we lose [bone mass], how we limit it and how we can get it back, there are some direct applications to those of us on the ground."

Whitson told subcommittee members that the current resupply needs of the ISS, which requires the steady arrival of unmanned Progress spacecraft every six months to support the outpost's two-person crews, are too great for a future moon base or Mars station.

"We need to build hardware at a much higher level of maintenance," Whitson said.

• Complete Coverage: ISS Expedition 11
• Fixing NASA: Complete Coverage of Space Shuttle Return to Flight