Hoffman relates difficulties as astronaut on space shuttleAstronaut Dr. Jeffrey A. Hoffman described his April flight on the shuttle Discovery in a lecture Tuesday. Hoffman was one of three shuttle astronauts from MIT.
Hoffman had worked on X-ray astronomy at the MIT Center for Space Research until the late 1970s, after which he left for astronaut training at the Lyndon Johnson Space Center in Houston, Texas.
The crew expected to perform several experiments, launch some satellites and return after five days. Shortly after launch on April 12, the crew successfully launched a small Canadian TELESAT communications satellite.
Trouble began with the launch of a SYNCOM satellite which failed to operate as planned. Ground controllers decided to attempt a rescue operation which included an improvised space-walk.
The satellite antennas were to have popped out 80 seconds after launch and the satellite was to have started to spin and propel itself into its own orbit. Neither event occurred.
The crew improvised "fly-swatters." These were to be attached to the ship's 50-foot manipulator arm and used to activate the satellite switch, the assumed source of the failure.
"We didn't know whether we were doing the right thing," Hoffman said. "The swatters turned out even better than what had been designed on the ground," he added.
Two crew members, one of whom was Jeff Hoffman, had to exit the ship and attach the swatters to the end of the manipulator arm. Hoffman said he "was greatly overwhelmed" when he first stepped out into space.
"The greatest thing was hanging out there and watching the world go by. It was the first time I felt like a satellite myself, revolving around earth." The entire operation took about three hours because of the low manipulative ability in a space-suit.
The ship was brought near the satellite after the space-walk was completed. The swatter was maneuvered using the manipulator arm and the switch was turned as planned. But this did not solve the problem.
The SYNCOM satellite had to be rescued during a subsequent space shuttle flight. The rescue was "a remarkably successful mission," Hoffman said.
Hoffman described the experiments and day-to-day life on board in detail. He showed slides of the crew watching precession-free spins of gyroscopes and playing with yo-yos, drops of lemonade and free-floating magnet-containing marbles.
"It's really a shame we can't take physics classes out there," Hoffman said. Some of the images presented at the lecture will be compiled and serve as educational films for physics classes.
Hoffman, an avid mountain climber, likened the food, hygiene and personal space on the shuttle to those of a camping trip.
The astronauts got some of the most fascinating views of the earth as the landscape beneath them changed at a rate of five miles per second. Hoffman spoke of and showed views of the Andes, the Nile River delta covered by a dust storm and the massive land erosion in Madagascar.
The crew saw 110 sunrises and 110 sunsets during the five-day mission. Hoffman showed a picture of a bright, perfect, red, white and blue ribbon on a black background as an example of what the crew witnessed.
Re-entry into the atmosphere, Hoffman said, "was like being in the inside of a meteor." Hot plasma surrounded and shock waves trailed behind the space shuttle.
Shuttle flights are scheduled
for December, January and March. The main objective of those flights will be to observe Halley's comet.
Hoffman tested one of the ultraviolet telescopes in April that will be used for observations of Halley's comet.
It seems that accurate observations will be possible despite the dust that gathers on the telescope during launch. As an astronomer, the observations will be the most exciting aspect of the trip, Hoffman said.