Johnson Space Center, Houston — One year after the explosion that destroyed the space shuttle Challenger, the nation's astronauts say they are wiser and more vigilant as a result of the accident that killed six of their colleagues and a New Hampshire schoolteacher. Astronauts interviewed ex-pressed general satisfaction that the astronaut corps has gained a greater role in decisionmaking and trouble-shooting within the National Aeronautics and Space Adminstration's manned space program. The astronauts believe their increased participation will result in safer flights. The frustration that many astronauts felt during the past year of questioning and ``down time'' in the shuttle program is yielding to a renewed sense of purpose as a newly announced shuttle crew begins preparations for a scheduled February 1988 flight.
Above all, the astronauts say they are ready and eager to fly.
``We're looking forward to getting back to the business of flying in space,'' said Capt. Frederick Hauck, the commander of the next shuttle flight, at a recent press conference introducing the five-man crew.
Today NASA has 84 astronauts, nearly 20 percent fewer than the 102 it had a year ago. The prospect of at least two years without shuttle flights led some astronauts to leave the corps, as did disagreements over the crew selection process.
But virtually no one appears to have left over concerns about the program's safety. ``Knowing many who have left, I'd say the dominant item in their mind was the long delays they faced in waiting for their next flight,'' says Don Lind, a former astronaut who left the corps in June to teach physics at Utah State University. ``Secondary reasons depend on the individual, but I would specifically exclude safety as anyone's reason [for leaving].''
NASA did not select any new astronauts over the past year, but the agency expects to recruit between 15 and 20 people this spring to keep the total number around 100. The agency already has more than 2,000 applications on file, many of which were received in the weeks following Challenger's demise.
Keenly aware that last year's disaster remains vivid in the public's mind, the astronauts and other space officials are careful to emphasize that spaceflight is a pioneering venture fraught with dangers. Yet there is a general conviction that shuttle flights will be safer in the future.
Next year's flight ``will be safer than the last time, I'm sure of that,'' says John Lounge, a mission specialist assigned to Captain Hauck's crew.
The National Research Council warned recently that NASA should not expect to accomplish necessary safety changes in time for a February 1988 launch date. The council, a private scientific organization overseeing redesign of the shuttle, also said NASA's decisionmaking process was based too much on the judgment of ``experienced practitioners'' and not enough on quantitative analysis.
Still, part of the astronauts' conviction that future shuttle flights will be safer stems from the fact that their colleagues are being heard more by NASA.
``The attentiveness to safety and our representation [in decisionmaking areas] have both improved,'' says Kathryn Sullivan, an eight-year veteran of the astronaut corps and the first American woman to walk in space. She says the shuttle program now has a ``separate channel'' for safety concerns that includes astronaut participation.
``We now have something closer to the airlines and any flying squadron,'' she says, ``where the guy worried about safety is not now the same one worried about making a certain flight schedule.''
Dr. Sullivan and others say the assignment of astronauts and former astronauts to key posts in NASA will also ensure that they have a voice. Rear Adm. Richard Truly, who flew two shuttle flights, is now head of the shuttle program; Robert Crippen, veteran of four shuttle flights, is deputy chief of flight crew operations; and astronaut Sally Ride was on the presidential commission investigating theChallenger accident.
``They're going to make darn sure that the astronauts' concerns are heard,'' Dr. Lind says.
Hauck says his crew will also place renewed emphasis on visiting and communicating with the various space centers and shuttle program contractors. He says they are determined to avoid the breakdown in communication and ``lapse into complacency'' that doomed Challenger.
``We're going to get out to [NASA's shuttle workers and contractors] and hear their concerns if they're not getting up through the channels,'' he says. ``As a Navy pilot, I found it was important for me to get eye-to-eye with the catapult officer from time to time.''
Despite the increasingly upbeat picture the astronaut corps presents as it moves out of Challenger's shadow and toward a resumption of flights, old areas of contention remain.
Some scientist-astronauts find, for example, that they often take a backseat to the test-pilot astronauts. Although they make up roughly half of the corps' total, the test pilots receive more shuttle assignments, which are made by one man, flight-crew operations director George Abbey. They also tend to be favored by NASA for top assignments.
``That's a real problem,'' says physicist Lind, ``and as long as George Abbey is selecting the crews, he's going to be flying the absolute minimum number of scientists he has courage to fly.''
Not all astronauts see that as such a problem. Sullivan, herself a scientist, says the greater frequency with which test pilots fly is understandable, as the mission specialists need more time between flights to ``cover all the bases'' of their work.
What she finds less acceptable, she says, is the broader neglect the country has allowed, since the days of the Apollo mission, of its science and technology base. She notes that manned missions to Mars had once been envisioned, using largely Apollo-era technology, for the mid-1980s.
Astronaut George Nelson, a member of Hauck's crew, agrees. ``We're losing our preeminence in space science to the Soviets, the Europeans, and the Japanese,'' he says. He adds that the nation's space military effort now has ``primacy.''
``There's no question,'' Dr. Nelson says, ``that space science within NASA is suffering. It's a problem.''