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How Many Astronauts Do We Need?

CREDIT: Courtesy, NASA

In a report issued earlier this month, the National Research Council (NRC) concludes that cuts to the NASA astronaut corps have been too deep and advises NASA to add more training slots. That's good news for scientists with orbital aspirations; while openings would remain highly competitive, the NRC recommendation would increase current corps size -- potentially by as much as 25%. But the greatest impact of the recommendation may be on the recruitment of young people into science and engineering, says former NASA official Joseph Rothenberg, co-chair of the NRC committee that explored this issue and co-author of the resulting report.

"It's just a little increment, but it really gave some of these young people some optimism." -- Joseph Rothenberg

In May 2010, NASA asked NRC to determine what factors were important to the future success of NASA's astronaut corps. Anticipating the end of the shuttle program, NASA had reduced the size of its astronaut corps from nearly 150 astronauts in 2000 to about 60.

Today's corps size is the bare minimum that will ensure that the United States can send at least three astronauts to the international space station (ISS) at any time, Rothenberg says. Rothenberg and the others on the NRC committee, including engineers, former astronauts, and flight specialists, studied astronaut-staffing contingency plans, taking into account potential retirements, illnesses, and other events that could keep mission-bound astronauts grounded. They concluded that although a corps of 55 to 60 astronauts could handle most situations under most circumstances, the corps' current staffing margin of error is inadequate to meet the agency's needs if too many bad things happen at once.

Joseph Rothenberg (CREDIT: Courtesy of Joseph Rothenberg)

"Historically, NASA has based the size of the astronaut corps on its immediate needs and the potential for unexpected needs to pop up," writes NASA spokesperson Michael Curie in an e-mail to Science Careers. "NASA is evaluating the size of the astronaut corps and is grateful to the NRC for its advice."

Rothenberg believes the agency is unlikely to expand its astronaut corps by the full amount the NRC recommends. More likely, he says, is an increase of five or six astronauts. NASA's decision will likely depend on the extent of budgetary constraints and NASA's independent conclusions, Rothenberg says.

The NRC report also concludes that NASA astronauts should receive additional training. Now that American astronauts will be thumbing a ride into space aboard Russia's Soyuz spacecraft, some of them must be prepared to pilot the Soyuz in emergencies. (Astronaut trainees must already be fluent in Russian in order to graduate from training.) Others should be trained to perform maintenance aboard the ISS, the NRC report adds. Such specialized training further highlights the need for an increased corps size, Rothenberg notes, because astronauts aren't always interchangeable.

Regardless of what NASA decides, Rothenberg believes the NRC report will affect recruitment of the next generation of scientists. "I've gotten a number of e-mails from 17-, 18-year-old kids who've been dreaming of becoming an astronaut, and they read the headlines. I don't know if they read the whole report, but they may have, and they look at the fact that we said they ought to increase [the corps size] slightly ... as more opportunity among the competition," Rothenberg says. "It's just a little increment, but it really gave some of these young people some optimism."