Magellan Team Rests After Emotional Highs and Lows
PASADENA, Calif. (AP) _ Magellan engineers tried to recover today from an emotional roller-coaster ride after the unruly spaceship gave them great pictures of Venus and ″moments of terror and of great happiness.″
″We’ve got to get the team rested,″ Magellan project manager Tony Spear told a news conference Friday at NASA’s Jet Propulsion Laboratory.
Magellan was launched from the shuttle Atlantis on May 4, 1989. It started orbiting Venus Aug. 10 on a $744 million radar-mapping mission to make the best pictures and maps yet of the cloud-covered planet.
The spacecraft returned its first pictures of Venus last week. New pictures released Friday, including a spectacular three-dimensional image, show a 20- mile-wide meteorite impact crater with a floor covered by lava flows.
Science and mission planning manager Tommy Thompson said engineers and scientists felt ″a little strung out″ after the spacecraft malfunctioned and lost contact with Earth twice: first for 14 hours starting Aug. 16, then for 17 1/2 hair-raising hours beginning Tuesday night.
″It’s kind of like having a date for the prom, stubbing your toe the night before, getting up the next morning and stubbing a toe on the other foot,″ Thompson said.
While Magellan mission control is staffed around the clock, many other team members were resting this weekend, he said.
Until engineers identify and fix the problem that cut the radio link, ″I think it’s likely to happen again,″ Spear said earlier Friday.
If contact is lost again, engineers are ready with new computer commands to ″kick start″ Magellan’s automatic safety systems and make the spacecraft re-establish contact with Earth immediately, Spear said.
″My heart can’t stand this 17-hour loss of signal″ again, he said. ″There are moments of terror and of great happiness after we recovered the signal.″
The emotional wear-and-tear showed a bit Friday as National Aeronautics and Space Administration officials contradicted each other on one possible explanation for the communication problems.
During the news conference, spacecraft system engineer John Slonski said the braking rocket Magellan used to slow down and go into orbit around Venus might have failed to separate fully, or might have burned some cables as it was jettisoned.
″It’s a possibility we’re investigating that the solid rocket motor really hasn’t gone away - that it’s still hanging on″ and bumping into Magellan, Slonski said.
Spear called that possibility remote and contrary to available evidence, but also said it was conceivable the rocket yanked out some cables on Magellan as it separated from the spacecraft.
Two hours later, the laboratory’s public relations office issued a statement saying there was ″currently no doubt the separation was complete.″ Spokesmen refused to elaborate when asked to explain the contradiction between that statement and those made by Slonski.
Even if the rocket had not completely separated, it wouldn’t prevent Magellan from conducting its mission, Spear said. The official mapping effort is likely to start no earlier than mid-September, two weeks later than planned, he said.
Engineers also were considering the possibility the communications failures were caused by problems with Magellan’s computer hardware or programs, or the unlikely chance Magellan is being affected by previously unknown electrical fields around Venus.
One of the biggest joys was that Magellan’s first pictures of Venus, made during an Aug. 16 radar test, lived up to NASA’s promise of being 10 times more detailed than the best obtained from radar on Earth or from the Soviet Venera 15 and 16 spacecraft in the mid-1980s.
The meteorite impact crater shown in pictures released Friday has a very smooth floor and a central peak. The smooth floor indicates the crater was flooded by volcanic lava, either during or sometime after the impact, said Steve Saunders, Magellan’s chief scientist.
He said the crater is relatively young geologically, 100 million to 150 million years old. It is named after Soviet sculptor Anna Golubkina, who lived from 1864 to 1927.
Other pictures from Magellan showed intense ″Venusquake″ faulting, lava flows and a network of intersecting ridges and valleys.