Lightning, Crystals Occupy Atlantis Crew
On their second day in orbit Friday, with the space probe Magellan safely on its way to Venus, the five astronauts on Atlantis settled down to routine business.
Among their tasks were an experiment testing crystal growth in space, tests of a commercial VCR camcorder that NASA hopes to use on future missions, photography of lightning on Earth and two brief firings of the shuttle engines over Hawaii to help the Air Force test an optical tracking system for rockets.
Magellan, which fired its two-stage rocket booster 7 hours and 14 minutes after liftoff Thursday, had accelerated to a speed of more than 25,000 m.p.h. to escape from Earth. By midday Friday, however, gravity had slowed the probe to its cruising speed of about 7,000 m.p.h. for the 15-month, 800-million-mile journey to Earth’s sister planet.
Magellan was almost precisely on course to its rendezvous, where it will use radar to map 80% of the planet’s cloud-shrouded surface, and controllers said it will require only a slight, planned course correction on May 21--a 5-foot-per-second increase of its 10,000-feet-per-second speed.
‘Couldn’t Be Better’
“The spacecraft is performing just beautifully . . . . It couldn’t be better,” said Magellan project director John Gerpheide of Jet Propulsion Laboratory.
The five-member crew was awakened on Atlantis’ 13th orbit by the theme from “Superman: The Movie” “in celebration of a super day” Thursday, according to mission control commentator Billie Deason.
“Everybody’s feeling good and trying to find their toothbrushes . . . “ radioed back commander David M. Walker.
The only significant problem the astronauts encountered was a balky Text and Graphics System--NASAese for a fax machine--that was being carried for the second time. Paper jammed in it, and mission specialists Norman E. Thagard and Mark C. Lee shut it down after they were unable to clear the jam.
Written instructions will be sent to Atlantis through the teleprinter that has been carried on every mission.
The crew did not have a lot to do today because they did not carry many experiments into space. “We sacrificed a lot of payload to have more (fuel and thus more) opportunity to get Magellan off the launch pad,” said flight director Ron Dittemore.
Despite the paucity of work, the shuttle, like all missions, will stay in space for at least four days. NASA has found that astronauts are generally recovered from any motion sickness by then, and are fully healthy for a return to Earth. The Atlantis is scheduled to land Monday.
Crystal Experiment
Friday morning, mission specialist Mary L. Cleave activated the fluids experiment apparatus, with which scientists will attempt to determine if large, perfect crystals of the semiconductors indium and selenium can be grown in the microgravity of space. Such crystals could have better electronic properties than the smaller, less perfect crystals that can be produced on Earth.
The microwave oven-sized apparatus moves a heater slowly down the length of a 9-inch rod of the semiconductor, melting a small area and then allowing it to cool slowly so that crystal growth is promoted. The first experiment may have been disrupted, however, because Walker and pilot Ronald J. Grabe fired the orbiter’s thrusters while the experiment was in progress, vibrating the specimen.
The thrusters were fired while Atlantis was over the Air Force Maui Optical Site on Mt. Haleakala, Hawaii. Firing the thrusters allowed technicians on the ground to test the sensitivity and accuracy of electro-optical sensors for monitoring spacecraft.
Later, the astronauts photographed lightning as they passed over Africa as part of a continuing project to develop a space-based lightning detection system. Such a system could lead to better weather prediction models for use in airline operations and to the development of lightning warning systems for outdoor crews of oil derricks, electric power companies, large cranes and construction equipment.
Photographs made by the shuttle will be compared to data obtained on the ground to monitor accuracy of location of the lightning and estimates of its intensity. The data will eventually be used to produce lightning monitoring satellites.
MAGELLAN: THE ‘BIONIC’ PROBE
The Magellan Venus probe scheduled for deployment by the Atlantis astronauts is made up mostly of spare space parts to save money after the Reagan administration axed a more ambitious project in 1981.
The National Aeronautics and Space Administration originally wanted to launch a probe called the Venus Orbiting Imaging Radar, or VOIR, a $750 million project to explore Earth’s closest planetary neighbor in unprecedented detail.
The Magellan craft itself costs $325 million, and the entire program $550 million. In the wake of the 1986 Challenger disaster, launch was delayed and the spacecraft had to be adapted for a different booster.
Pedigree of Magellan’s parts:
1. MAPPING ANTENNA--Magellan’s 12-foot radar antenna is a spare left over from the successful Voyager program of the 1970s, as is the spacecraft’s equipment module.
2. FORWARD EQUIPMENT MODULE--Radio transmission system from the Ulysses sun-study probe.
Gyroscopes from the Voyager program.
3. BUS--An attitude control computer, the command computer and a critical electronic unit came from NASA’s Galileo program, an ambitious project to send a probe to Jupiter in October.
Internal propellant tank design for thrusters from the space shuttle program.
4. PROPULSION MODULE--Thruster rocket designs from the Voyager and Viking projects.
Braking rocket design from a commercial solid-fuel booster developed for communications satellites.
