Satellite rescue may shed light on techniques for building space stations
Space shuttle Discovery's spectacular satellite rescue mission has given space planners some new ideas to think about. The fact that astronauts Joseph P. Allen and Dale A. Gardner were, by themselves, able to hold, position, and maneuver the 21-foot-long, 1,200-pound satellites has given National Aeronautics and Space Administration (NASA) experts a new appreciation of the capability of humans working on orbit.
Although weightless, the satellites still had all the inertia of massive objects. NASA had not planned to have the astronauts try to manhandle them. Instead, the astronauts were to attach frames that would allow the shuttle's mechanical arm to do the heavy work. But a small fitting on Palapa, overlooked in the planning, prevented the astronauts from attaching the frame. Joe Allen, by himself, held each satellite steady, while Dale Gardner attached fixtures for berthing it in the shuttle cargo bay. Working together, the astronauts maneuvered the satellites into their resting places.
This is valuable experience for Johnson Space Center engineers who are working on the design of the proposed space station. Center director Gerald Griffin called the ability of space-suited astronauts to handle large masses ''a significant (unsuspected) capability.'' He explained: ''It is another point to consider which we didn't have before when we think about how to assemble a space station. You might not after all need a finely tuned maneuvering system.''
Safe return of the Palapa B-2 and Westar 6 satellites - once considered lost - also has been ''a psychological boost to the insurance industry,'' according to Lloyd's of London underwriter Stephen Merritt. The possibility of such recovery now can be factored into insurance planning. And, as American underwriter James Barrett of International Technology Underwriters has noted, satellite builders should now be encouraged to design their units to aid such recovery.
At this writing, the state of the retrieved satellites was not yet fully known. They were believed to be in reasonably good condition. Mr. Merritt, chairman of Merritt Syndicates Ltd., said resale of the refurbished satellites should be ''completed very shortly.'' He added, ''We would expect to recover about $50 million.''
This would scarcely begin to cover the $180 million insurers have paid in claims, plus $10.5 million for recovering the satellites and an as-yet undetermined sum for repairing them. Insurance rates are expected to rise steeply because of especially large losses - about $300 million this year - for satellite operations generally. Thus, Merritt did not see much immediate economic gain from the satellite rescue. Nevertheless, the possibility of rescue has changed the perception of risk in this field. ''The industry is absolutely over the moon about it,'' he said.
Meanwhile, there will be no rest for the spaceship Discovery. It is being serviced to take over a secret Department of Defense mission that its sister ship, Challenger, was to have flown Dec. 8. But uncertainty about the bonding of many of Challenger's heat-shielding tiles has taken that spaceship temporarily out of service. The DOD mission has been rescheduled for Jan. 21 or 22.