CAPE CANAVERAL, Fla. — Half of NASA's shuttle workers are worried about their future after next year's fleet retirement, an employee survey shows.

Sixty percent are dissatisfied with information they are receiving about the shutdown and NASA's future.

Three of four might leave for the right opportunity.

But only 5 percent are actively seeking new jobs.

In fact, 80 percent are likely to stay through the six remaining missions. And most supervisors believe they'll have the right people with the right skills to finish the program safely.

The findings — outlined in NASA employee surveys obtained by Florida Today through the Freedom of Information Act — illuminate a major safety issue.

Losing critically skilled workers is a top risk for the $3 billion-a-year shuttle program, ranking right up there with potential rocket booster or engine failures.

An exodus would raise the chances of catastrophe as NASA aims to complete the International Space Station.

"I can't think of anything more important," said Retired Navy Vice Adm. Joseph Dyer, chairman of the Aerospace Safety Advisory Panel, which was created by Congress after the 1967 Apollo 1 launch pad fire.

"At the end of the day, flying high-technology machines into space is a business in which safety rides on the shoulders of skilled, hard-working folks."

NASA officials say the surveys show extraordinary commitment in uncertain times. NASA's shuttle program employs 10,300 contractors and 1,500 civil servants in eight states and Washington, D.C. Most of them work at Kennedy Space Center, Johnson Space Center in Houston, Marshall Space Flight Center in Huntsville, Ala., and Stennis Space Center in Bay St. Louis, Miss.

Contractors will bear the brunt of the reductions when the fleet retires. Some 7,000 contractor jobs at Kennedy Space Center are projected to be lost. NASA civil service workers almost certainly will find new work within the agency. So any sort of angst among those workers is telling.

"Are they concerned? Absolutely," said NASA survey administrator Sue Leibert.

But "people still want to be in the program. They are committed to NASA. They are committed to the shuttle. They want to stay to the end," she said. "They want to be a piece of history."

The safety panel recently visited Kennedy Space Center.

Dyer noted "considerably less anxiety" from supervisors about retaining critically skilled NASA and contractor workers.

"I think it speaks to the dedication of the space work force," he said. "We came away appreciative and encouraged."

NASA's 2009 survey of civil service shuttle workers shows: