The five veteran astronauts who flew Discovery into space say the most anxious moments of their nearly flawless flight came during liftoff, the point at which Challenger exploded 32 months ago.

Pilot Richard Covey said Tuesday that although he had flown before, he still was "a bit taken back" by the power of the rockets that thrust the shuttle into orbit Sept. 29."It was a very, very long 8 1/2 minutes" until the main engine cut off, Covey said. "I think we all felt that way," Covey said during the crew's first post-flight news conference at the Johnson Space Center.

"I'm sure we were all thinking, to some degree, about the fact that the last time this had been attempted, it wasn't successful. You never forget that," he said.

The Challenger explosion, which occurred 73 seconds after liftoff on Jan. 28, 1986, and killed all seven astronauts aboard, was blamed on a faulty booster rocket. The rockets were redesigned and NASA officials have found no damage in the new boosters.

Despite the anxious moments, Discovery's astronauts praised the shuttle's performance and its success in putting Americans back into space.

"We can look back on a flight that as far as I'm concerned was picture perfect," said Discovery commander Frederick Hauck, who announced the mission would be his last. Hauck, a Navy captain, said he is considering what he will do next, but said he has not resigned from the National Aeronautics and Space Administration.

"I don't think we have any ghosts hovering above us anymore," Hauck said, referring to doubts cast on the space agency because of the Challenger explosion.

During the four-day mission, Hauck, Covey, John M. Lounge, David C. Hilmers and George D. "Pinky" Nelson deployed a $100 million communications satellite, tested shuttle systems and conducted 11 experiments before landing at Edwards Air Force Base, Calif., on Oct. 3.

Although a detailed account of the mission showed a few minor problems, including trouble with a cooling system, the only complaint the astronauts had Tuesday concerned the bulky pressure suits worn during launch and landing.

While watching a 20-minute film about the flight that included shots of the astronauts getting into the 75-pound suits before landing, Nelson said, "It hurts just to watch it."

Nelson said that although the suits, which are part of a new escape system, are "pretty uncomfortable," a few modifications such as a better fan and a less bulky harness could improve them.