alb@alice.UUCP (07/06/83)
In a report in Aviation Week and Space Technology, there was speculation that the cause of the IUS failure that sent TDRS-1 into the wrong orbit was a deflated ring that cushions the nozzle of the second stage. Eighty seconds into the second stage, the rocket malfunctioned and sent the satellite into a U-turn and then sent it tumbling out of control. A preliminary report says that the 25,000 pounds of thrust against the ring may have overheated it and caused it to puncture and deflate. Without the ring, the nozzle locks up, and the rocket becomes an ''unguided missile,'' completely devoid of steering. It may not be until June of next year when the problem will be solved and the second stage sufficiently tested. In the mean- time, NASA is looking for other means of propelling satellites ejected by the shuttle into geosynchronous orbits, one of which may be the use of a Delta rocket's third stage.