The space shuttle Challenger made a perfect landing in the Mojave Desert today, ending a maiden voyage described as the best of the six shuttle missions flown so far.

Maneuvering the 100-ton space liner through stiff crosswinds, Commander Paul J. Weitz brought the shuttle to a full stop in the middle of the main runway with more than 9,000 feet of concrete to spare.

Less than half an hour later, Weitz and astronauts Karol J. Bobko, Story Musgrave and Donald H. Peterson were out of the spacecraft looking over the shuttle. Challenger came through five days in space with fewer scars and blemishes than the first space shuttle, the Columbia, picked up on any of its five trips.

"The Challenger is a better spacecraft than Columbia and that's what one expects the second time around," Air Force Lt. Gen. James A. Abrahamson, associate administrator of the National Aeronautics and Space Administration, told a post-landing news conference. "We've had fewer things go wrong on this flight than on any of our other flights."

The main thing that went wrong during the mission took place aboard the Tracking Data and Relay Satellite deployed into orbit by the shuttle crew on the second day of its mission. The second stage of a rocket motor attached to the satellite apparently misfired and sent it into an orbit that dips almost 9,000 miles closer to Earth than it should.

An investigative board has been set up to find out what went wrong with the second-stage engine. Abrahamson disclosed today that an Air Force camera in Socorro, N.M., 80 miles south of Albuquerque, photographed the engine burn and recorded from a distance of almost 20,000 miles what may have gone wrong to put the $100 million communications satellite into the wrong orbit.

"You can see the plume of the engine exhaust stretching out in space for 300 miles," Abrahamson said. "At the time of the failure, you can see the plume turn hard about and kind of push it over in a different direction."

Finding out what sent the TDRS satellite into an errant orbit is crucial to the eighth and ninth flights of a space shuttle later this year. On the eighth flight, now scheduled for the first week of August, Challenger will take a second satellite into orbit. The second satellite will complete a network that will serve as a command post for future earth-orbiting satellites flown by the United States.

On the ninth flight, the space shuttle Columbia is due to carry the $1 billion Spacelab experimental station built by the European Space Agency into orbit. Two additional astronauts, one of them a European, will fly in Spacelab, performing no fewer than 40 scientific experiments that require constant communication with earth.

"We need both of those satellites in orbit to run a complete Spacelab mission in September," Abrahamson said. "We will not fly a second satellite on the eighth shuttle flight until we understand what went wrong on this flight."

The next shuttle flight--the seventh--is tentatively scheduled for June 9. Challenger on that flight will be the first to land at the 15,000-foot runway at the Kennedy Space Center in Cape Canaveral, only a few miles from its launch site.

Right now, the TDRS satellite is in an orbit that must be bumped about 9,000 miles from its low point sometime in the next two weeks. The procedure will take an estimated 850 pounds of the more than 1,200 pounds of hydrazine fuel on board the satellite that was sent up to fuel motors used to keep it from drifting out of orbit over the next 10 years.

The first of 14 two-hour burns of two small thruster engines will be made in the next week or two to start moving the satellite into a higher and more circular orbit. When that is done, the satellite will be put into operation.

Abrahamson said that Spacelab could be flown in September using one communications satellite but that only half of its scientific goals would be achieved.

"The Europeans are our partners in Spacelab and they want it to go off on time in September," Abrahamson said. "We're convinced we will understand the engine misfire that raised so many problems on this flight in time to do that but it will be a very tight schedule indeed to make everything work on time."

Today, coming out of orbit over the western Pacific Ocean, Challenger flew by its five computers as precise a downward path as any shuttle flight before it. Burning onboard engines a fraction of a second less than they were supposed to, the astronauts came across the California coast, then flew over the lake beds that today were under two feet of water from the heavy rains that have pelted southern California for the last few months.

"We see balmy Lake Edwards," Weitz said as he made the turn at the far western end of the desert. "There's probably a lot of sailboats out there today." Minutes later, Weitz had Challenger on the ground coasting to a landing on its nosewheel and two wingwheels. The landing took place precisely at 1:53 p.m. EST, plus 42 seconds. The scheduled time for landing was 1:53.

"It was a good burn, right down the pipe and smooth all the way," Weitz reported. He said he had given "everybody a last vote at 30 seconds to see if they wanted to go around Earth one more time and all I got was blank looks--nobody wanted to do that."

A quick ground inspection of the shuttle showed that three chunks of thermal blankets were bent or missing from pods alongside the tail on top of the craft. The blankets are a new type of heat shield used on parts of the Challenger.

The damaged blankets posed no problem, Abrahamson said, adding, "We can resolve that pretty easily."

"It was a great mission, incredibly routine, which is what we want," Abrahamson said. "The guys put the bird right in the middle of the runway, a good Air Force landing."