A robot probe was flying right on target to Venus and Atlantis' astronauts landed here after a successful four-day space shuttle mission that put U.S. planetary exploration back on track.

At Edwards Air Force Base, Calif., initial inspections of the shuttle showed little damage to the thermal tiles, the National Aeronautics and Space Administration said."The vehicle looks as clean as any one that I've ever seen," said Navy Rear Adm. Richard Truly, NASA's acting associate administrator for space flight.

Commander David Walker, pilot Ronald Grabe, and mission specialists Mary Cleave, Mark Lee and Norman Thagard were greeted at Ellington Field late Monday by 200 relatives, friends, co-workers and even a few of the family dogs.

"It's really nice to have the mission finished, and we couldn't have done it without you," said Cleave, who helped deploy the Magellan probe.

She said the astronauts had a great time and it was good to be back knowing that there's a spacecraft en route to Venus and "we were all a part of it."

After returning to work Tuesday, the crew planned to view photographs taken during their 1.68-million-mile journey, Johnson Space Center officials said.

The 97-ton Atlantis glided to a smooth landing as scheduled at 3:43 p.m. EDT Monday afternoon.

Twelve minutes before touchdown, the crew was ordered to land on a concrete runway rather than a hard-packed clay runway because crosswinds on the runway were too high.

"Obviously this mission was an outstanding success," NASA science chief Lennard Fisk told reporters at Edwards Air Force Base.

"Magellan is on its way to Venus. The deployment was very successful. The trajectory is about as accurate as you can get. The spacecraft is working without any difficulties whatsoever."

About 27,500 spectators, the smallest crowd ever to attend a shuttle landing, withstood the 90-degree heat to watch.

Thursday's deployment of Magellan was the mission's primary goal.