Committee to NASA: Train more astronauts

NASA has already lost dozens of astronauts and needs to take action to make sure it has enough trained personnel to keep the International Space Station fully staffed, a National Research Council panel of experts recommended on Wednesday.

The astronaut corps has shrunk from nearly 150 members in 1999 to 61 in 2011, according to the report by NRC's Committee on Human Spaceflight Crew Operations. Many have retired and have not been replaced as the space shuttle program wound down and as the needs of the International Space Station changed from building it to operating it.

"In the half century since the flight of Yuri Gagarin, more than 500 humans have orbited Earth or traveled to the Moon," the report reads. "Approximately 61 percent have been Americans."

But NASA is not adequately planning for future needs, said the panel. "For human exploration and operations beyond low Earth orbit, the ISS task and skill set will need to be augmented by training for planetary surface operations, mission-specific operations and landing requirements, and science operations," the report reads.

"Viewed as a supply chain, astronaut selection and training is very sensitive to critical shortfalls; astronauts who are trained for specific roles and missions can't be easily interchanged," said committee chairman Frederick Gregory, who commanded three shuttle missions and formerly was NASA's deputy administrator.

"With the retirement of the shuttle program and the uncertainty during the transition to a fully operational ISS, it's even more important that the talent level, diversity, and capabilities of the astronaut office be sustained," added panel cohairman Joe Rothenberg, a former senior NASA official now with the SSC (previously known as the Swedish Space Corp). "Making sure NASA maintains adequate training facilities is also essential to ensure a robust astronaut corps."

Early astronauts were recruited mostly from a cadre of adventurous test pilots, but today's astronauts must be able to deal with Japanese and Russian crewmates and equipment. Health has also turned out to be a big factor - 13 astronauts have become medically ineligible for long-duration missions, the report says. Many have also suffered vision problems, bone loss, physical injuries, or radiation exposure severe enough to make them ineligible to go back to the space station.