karn (10/27/82)
ESA has announced that Amsat Phase-IIIB will now fly on April 2, 1983. The board of inquiry filed its report on the launch failure of Ariane L5 on Oct 15th. As was already stated, the third stage cryogenic hydrogen turbopump failed before normal shutdown, causing the failure. It is now believed that the failure may actually have been due to overtesting of the turbopump gearbox that weakened the unit before launch. In any case, ESA is delaying the launch in order to subject the next launcher to a very close inspection before another launch. This makes us feel a little better; there is a saying that the best launch to go on is the one right after a failure - everybody is on their toes. The Phase 3B mode "B" transponder (70 cm in, 2 m out) has been tested in a thermal vacuum chamber, and found to meet specifications. Peak power output is approximately 50 watts, and the AGC is set to maintain an average power output of about 15 watts. Transponder input power at the antenna terminals to obtain the average power output is about -105dbm. Bandwidth is almost exactly 150 khz. The mode "L" (23 cm in, 70 cm out) transponder has been tested and found to not yet meet specs. Power output is low by about a DB, and the third-order intermodulation products are only 17 db down. With this latest launch slip, there will probably be time to improve the L transponder. Phil Karn, KA9Q