Columbia Due to Land Today as Snow Melts at Edwards Base

The shuttle Columbia was expected to touch down in California early today, ending a 10-day mission in which the astronauts rescued a falling laboratory that will help scientists design spaceships of the future.

The five crew members spent their last full day in orbit testing the shuttle’s flight control systems and stowing their gear and experiments, then said good night to mission control and went to bed Thursday afternoon.

Although some snow fell Thursday at Edwards Air Force Base, Calif., where the shuttle was to land on a concrete runway, it had melted by late morning and NASA officials said the weather was expected to be acceptable for touchdown.

“It’s nice, it’s sunny. We’ve got a few high clouds,” said Nancy Lovato, a National Aeronautics and Space Administration spokeswoman at the Mojave Desert base. “We had expected things to improve dramatically during the day and they did.”

If the shuttle cannot land as planned, there are several options for Columbia, including a landing Saturday at Edwards.

Tucked in the shuttle’s cargo bay for the ride home was an 11-ton scientific satellite that had been in orbit for nearly six years before being snared by the astronauts a week ago. That added weight made Columbia the heaviest shuttle for a landing.