The landing site for the space shuttle Columbia, preparing to make its third flight, has been changed to the White Sands Missile Range in southern New Mexico because of flooded runways at California's Edwards Air Force Base.

"We believe this is the prudent thing to do," Kennedy Space Center Director Richard Smith said, "especially since there was no guarantee the runways at Edwards would dry out for another week."

Heavy rains fell all day Wednesday in the Mojave Desert, leaving more than an inch of water on the normally dry lake beds where Columbia landed at the end of its first two flights. The third flight is scheduled to leave Monday from Kennedy Space Center in Florida with astronauts Jack Lousma and Gordon Fullerton at the controls.

It is cheaper to move the landing equipment to White Sands than postpone the launch and wait for the Edwards runways to dry out. Each day of delay in flying the shuttle from Cape Canaveral costs the National Aeronautics and Space Administration $3 million.

A specially trained landing team immediately began loading the shuttle's support equipment on a 23-car train that was to set out today on the 1,000-mile trip from Edwards to White Sands.

Lousma and Fullerton are to take Columbia into orbit Monday, spend seven days in space and return to Earth the following Monday, March 29. The upcoming flight will be the third in a planned series of four test flights before the shuttle "goes operational" and begins to carry satellite cargo into space late this year.

Lousma and Fullerton have practiced landing countless times in jet aircraft at White Sands, where the two gypsum-covered desert runways are as wide and almost as long as the seven-mile-long runway at Edwards. The main runway at White Sands is five miles long and is located in a huge valley between two mountains.

The astronauts have also practiced landing at a three-mile-long concrete runway at Kennedy Space Center, which they will only use if they lose an engine during their first four minutes of flight from Cape Canaveral.