WHAT NEXT? NASA’S astronauts have been asking just that, now that the space shuttle program is ending and their odds of flying anywhere good anytime soon are getting smaller. The Endeavour was scheduled to launch April 29, and the Atlantis is supposed to fly the last shuttle mission in June - and all the seats are spoken for.

NASA has curtailed manned space flight. Some of its astronauts will fly to the International Space Station in Russian Soyuz capsules.

“Morale is pretty low,” said Leroy Chiao, a former astronaut who now works for a company that wants to offer space flights for tourists. “This is a time of great uncertainty.”

Under President Obama, NASA’s human spaceflight program has been curtailed. The Ares I and Constellation programs, which were meant to succeed the space shuttles and take astronauts to the moon, were canceled, and NASA is instead hiring outside companies to devise alternatives. Over the next few years, American astronauts will be competing for a handful of slots on the International Space Station, flying there on Russian Soyuz capsules.

“We hope we will overcome this hurdle and continue to explore,” said Peggy A. Whitson, the head of NASA’s astronaut office, whose job includes selecting the astronauts who will fly each space mission. While people’s spirits are a little down, she said, “we’ll have to see - NASA has gone through different phases like this before.”

Last year alone, 20 astronauts left NASA’s active-duty roster; today, 61 remain, down from a peak of about 150 in 2000. Back then, NASA was gearing up to staff the International Space Station and the shuttles that supplied it.

The shift has made a big difference to people like John M. Grunsfeld, the Dr. Fix-It of the Hubble Space Telescope,who has flown five missions for NASA. After his last flight, in May 2009, he asked Dr. Whitson about his chances of returning to space. “She was honest,” Dr. Grunsfeld said. “Slim to none.”

So in January 2010, he left NASA to become deputy director of the Space Telescope Science Institute in Baltimore, which operates the Hubble.

Captain Scott D. Altman of the Navy has flown four missions for NASA. But at 1.93 meters tall, he does not fit into a Soyuz capsule. He now works for ASRC Research and Technology Solutions in Maryland, which does engineering work for NASA .

NASA will still be hiring astronauts, though not people of Captain Altman’s vintage. In the next year or two, the agency will recruit a new class of 6 to 12 astronauts, Dr. Whitson said. If NASA decides to reduce tours of duty at the space station from six months to four, that would mean a need for even more astronauts.

Meanwhile, opportunities for astronauts outside of NASA are small but growing.

Virgin Galactic, part of Richard Branson’s empire, is seeking three space pilots for its SpaceShipTwo rocket plane, which may begin space tourism trips next year. While SpaceShipTwo will take suborbital hops that provide only a few minutes of weightlessness, other companies ? like Boeing and the Space Exploration Technologies Corporation, better known as SpaceX ? are developing spacecraft that will be able to fly to the International Space Station and elsewhere.

Garrett E. Reisman, who joined the astronaut corps in 1998, left NASA in March for SpaceX . Dr. Reisman had logged more than three months in space and done work on the space station’s robotic arm.

“Being an astronaut is the coolest job ever,” said Dr. Reis man, 43. “It was very, very difficult to voluntarily leave.”

If Dr. Reisman had stayed at NASA, he would have had a chance to fly again, but he decided to move on. Now he is working on a rocket (the Falcon 9) and a spacecraft (the Dragon) that are meant to take passengers and cargo to the space station.

“It’s an engineer’s dream to design a spaceship,” he said. “To me, it seems like we’re on the verge of a golden age of spaceflight - that’s where I wanted to be.”

For every astronaut who quits NASA because of age or a lack of opportunity, there are any number of young people aspiring to fill their shoes.

The job is still as romantic as the standards are stringent. According to NASA’s Web site, astronaut candidates must be able to swim three lengths of a pool in a flight suit and tennis shoes; an advanced degree in science or math is a plus.

The requirements are even stricter for people who want to work in the space station: You must speak Russian, know robotics, be trained for spacewalks and be healthy enough to spend six months in space.

“Being in space is like being someplace magic,” said Colonel Pamela Ann Melroy of the Air Force, the second female astronaut to command a shuttle mission.

She left NASA in 2009, knowing that there would be intense jockeying by astronauts seeking to command one of the few remaining flights.

“I didn’t really want to get into a situation where I was hanging around hoping that I would get one of them,” she said. Colonel Melroy is still wistful about the lost prospect of flying on the Ares I. “That would have been a hoot,” she said.

Garrett E. Reisman recently left NASA for SpaceX, a private company.

Some companies are looking for pilots for space travel. Visiting the
Hubble space telescope in 2009.


By KENNETH CHANG