Discovery's astronauts, achieving their crucial task of satellite delivery with precision, settled into a workmanlike routine Friday, performing scientific experiments and taking time out for sightseeing.

"The launch and us getting back to space is something that really means a lot to me," said Richard Truly, the NASA shuttle director who supervised the post-Challenger recovery. "And looking at today's front pages, I think it means a lot to the country. There'll never be another countdown that meant so much," he said in an ABC interview.With the triumph of Thursday's launch behind them, the Discovery crew began its workday 184 miles above the Central Atlantic, just after 3:30 a.m. MDT.

Mission Control supplied a morning wake-up that began with a loud and bracing, "G-o-o-d Morning, Discovery!" Robin Williams, who perfected his deejay routine in the movie, "Good Morning, Vietnam," prepared the tape for a Houston radio station.

The crew learned immediately that the NASA satellite they released Thursday evening had arrived overnight at its work station high above Earth.

"We're there. We're on orbit. We're very, very happy," Ed Bangsund of Boeing said Friday. The firm manufactured the rocket stage that sent the satellite to its final orbit.

Air Force satellite controllers in Sunnyvale, Calif., told the Discovery crew that "the final velocity shortfall is an amazing zero-point-one feet per second," which Mission Control called a feat "of some considerable precision." It means the satellite was sent into precisely the right orbit.

Friday's relatively quiet schedule contrasts with the tense drama of fire and thunder as Discovery rocketed into orbit Thursday and revived an American space program that had been devastated 32 months earlier by the explosion of Challenger and the death of its seven crew members.

"We sure appreciate your all getting us up in orbit the way we should be," Discovery's commander, Frederick H. Hauck, told Mission Control. "We're looking forward to the next four days - we have a lot to do, and we're going to have a lot of fun doing it."

The crew was asked to photograph "some of the natural phenomena of the planet Earth" - including Pacific thunderstorms, a volcano lava flow in Ethiopia and coastal erosion damage from the Hurricane Gilbert on the Yucatan Peninsula.

Friday's flight plan was deliberately conservative to enable the crew to carefully check the scores of system modifications made in the spacecraft since the Challenger explosion.

Little more than six hours into the mission, crewmen John M. Lounge and David C. Hilmers, operating from a panel inside the cabin, released a $100 million Tracking and Data Relay Satellite. The craft was sprung from a tilt-table that raised out of the cargo bay, and it glided effortlessly into an orbit all its own.