Shuttle Ozone Mission Ends; Science Flight Is Set for Saturday

NASA landed one shuttle Saturday after a mission that was extended by the weather and got ready to launch another shuttle in just one week, the shortest time between manned missions in the history of U.S. space travel.

Discovery and its five astronauts glided through a clear sky to a landing at the space center shortly after sunrise, ending a nine-day atmospheric research mission.

Rain and clouds had blocked Discovery’s planned homecoming Friday, but that allowed the crew to conduct additional research.

A quick check showed the shuttle to be in good shape. “We couldn’t have asked for things to go better,” deputy shuttle director Brewster Shaw said.

Mission scientist Tim Miller predicted that the flight, which measured the sun’s influence on destructive airborne pollutants, would make “a major contribution to the understanding of Earth’s climate system.”

The 55th shuttle mission was the second in 13 months devoted to atmosphere research. A similar flight is planned in October, 1994.

Scientists from the United States and five European nations used a $75-million collection of remote-controlled instruments in Discovery’s cargo bay to investigate how ultraviolet radiation contributes to ozone damage caused by airborne pollutants.

The crew of four men and one woman also deployed and retrieved a small satellite that made a two-day study of the sun.

The shuttle made 148 orbits of Earth, covering 3.8 million miles before it returned to where it was launched on April 8.

A few miles from Discovery’s landing strip, technicians were preparing the shuttle Columbia for a much-delayed science flight sponsored by Germany. The nine-day mission is now five years overdue.

The latest setback occurred March 22 when a stuck valve caused Columbia’s main engines to shut down three seconds before liftoff. The engine shutdown--the first at the pad in eight years--prompted NASA to push the Discovery flight ahead of Columbia.

But Discovery’s relatively problem-free flight allowed National Aeronautics and Space Administration officials to proceed with plans for a send-off of Columbia next Saturday.

If the shuttle Columbia is launched on schedule, it would be the shortest interval between a landing and launch in 32 years of U.S. human space flight. The record of 10 days was set in 1985.