Five military men flew the space shuttle Atlantis back to Earth yesterday in a successful end to its maiden flight, the second secret shuttle mission for the Defense Department and the 21st shuttle mission since the program began in April 1981.

"Of course, I can't say anything about our mission, but I can say Atlantis performed superbly its first time in space," Flight Commander Karol J. Bobko, an Air Force colonel, said three hours after what looked like a flawless landing on the desert floor at California's Edwards Air Force Base.

"I've flown Challenger, Atlantis and Discovery now, and I think that NASA really has quite a fleet of orbiters and that we have a great national asset here," he said. Atlantis is the last of four shuttles.

Bobko's remarks were the first public statement by an Atlantis crew member since the 100-ton spaceliner was launched from Cape Canaveral Thursday on a classified mission to place in orbit two communications satellites.

Neither Bobko nor any crew member had said anything publicly about their flight before launch, during liftoff or during four days and two hours in orbit.

Ground Operations Manager Fritz Widick of the National Aeronautics and Space Administration said Atlantis was in "excellent condition" at the end of the 1.7 million-mile flight, although engineers were inspecting an area on the underside of the left wing to see if tile-insulation damage might have exposed its aluminum mainframe to searing reentry heat.

A region along the portside engine pod under the shuttle's tail was streaked with discoloration that may have been caused by such heat.

Widick said Atlantis' brakes came through the 190 mph landing on the lake-bed runway with only "minor damage" to one of four brake assemblies on the main landing gear.

Bobko appeared to apply minimum braking after landing into a stiff headwind that brought Atlantis to a stop on the center line at the halfway mark of the 15,000-foot desert runway.