Extra Day in Orbit Brings Science Bonus : Space: Astronauts conserve sufficient electricity to power added laser light atmospheric experiments. They are to return to Earth Monday.
The space shuttle Discovery showered Earth with lightning-quick pulses of green laser light Saturday, a day of bonus science for the astronauts and researchers on the ground.
It was much quieter and more subdued than Friday, when two of the crew took turns using a jet pack for the first untethered spacewalks in a decade.
“It’s a little bit disorienting,” spacewalker Carl Meade told a radio interviewer Saturday. “But other than that . . . it felt quite normal outside.”
“I tell you, it was absolutely phenomenal,” said astronaut Jerry Linenger, who directed the spacewalkers from inside the cockpit.
The mission originally was supposed to end today after nine days, but the astronauts conserved enough electricity to allow for a 10th day for science work. Landing was rescheduled from today to 11:24 a.m. PDT Monday.
As of Saturday, ground controllers had fired more than 1 million laser pulses from Discovery for a study of the atmosphere. Researchers were elated, especially those who had lost data because of earlier equipment failures.
“We’re making up for it, getting as much as we ever hoped for and more,” said laser experimenter Bob Menzies, an atmospheric scientist at the Jet Propulsion Laboratory in Pasadena.
The six astronauts could see the pencil-thin, fluorescent green pulses streaming from Discovery at a rate of 10 per second.
But they couldn’t see the laser light reflecting off the tops of clouds or Earth’s surface.
And there were no reports of anyone on the ground seeing the laser pulses, NASA said.
An instrument aboard Discovery collected the reflected laser light, allowing Menzies and other scientists to calculate the altitude and density of desert dust and other pollutants in the atmosphere.
They will use the findings to better understand global weather; one of Saturday’s laser targets was Typhoon Melissa in the Pacific Ocean.
It’s the first time the $25-million laser package has flown in orbit.
The National Aeronautics and Space Administration gave up trying to fix a laser-data recorder aboard Discovery, which never worked right from the start. The recorder was needed to save any laser measurements that could not be transmitted instantly to ground controllers; that turned out to be a small portion of the data.
Researchers studying the exhaust from the shuttle’s steering jets also had to contend with a data-relay problem, which popped up again Saturday. Astronauts worked around the problem and fired the jets at instruments carried by an 82-foot-long beam extended from the shuttle.
NASA wants to know how engine exhaust affects solar panels and other structures in space before sending Atlantis to dock with Russia’s Mir space station in May.
