Data Beamed Up by Laser Received by Shuttle Crew

After four days of trying, astronauts aboard the space shuttle Discovery received laser signals Sunday that were beamed up at them from Florida by the Defense Department.

The lime-colored light signals, which contained navigation data, were sent from an Air Force facility in Palm Bay.

“The green laser was clearly visible, visually and through the camera,” said shuttle commander David Walker. “Whatever they’ve done to change the laser on the ground has fixed our problem.”

Operators of the Palm Bay station had replaced the laser transmitter before firing Sunday’s test beams. The old transmitter had been operating at just 20% of normal power, said Dave Hess, a spokesman for the Air Force Space and Missile Systems Center.

The next two laser tests failed, however, one because of bad weather and the other for unknown reasons.

Until Sunday, bad weather at laser stations scattered throughout the United States had thwarted the Army experiment. Fourteen laser tests had been scheduled through Sunday, four of which were scrapped because of clouds, rain or snow and two that were attempted but spoiled by clouds.

The Army wanted to see if lasers could relay navigation data from the ground to space. Such information currently is transmitted via radio, which is more susceptible to enemy detection.

“The concept has been proved” as a result of Sunday’s success, Hess said.

Discovery’s five astronauts, all military officers, also enjoyed success with a military camera experiment, although they had to switch some ground targets at the last minute because of cloudy weather.

The camera system provides the latitude and longitude of ground targets within 2.3 miles.

The seven-day mission is scheduled to end Wednesday with a landing at the Kennedy Space Center.

Because of dismal weather predicted for landing day, Mission Control instructed the astronauts to conserve power by turning off unnecessary lights, heaters and other equipment. Officials said this will help if Discovery has to stay up longer than planned.