karn (09/22/82)
Some more details on the successful salvage effort at SRI which regained control over the Uosat-Oscar-9 spacecraft, which had been unable to respond to commands since April 1982: The SRI team commanded the beacons off at 22:35 UTC on 20 September, using an enormous amount of effective radiated power on the 70 cm command frequency. The earlier problems with the SRI effort appear to have been due to ground command encoder problems and outdated orbit element sets that gave inaccurate antenna pointing instructions (the SRI dish has a 3 db beamwidth of less than a degree at 70cm). The command encoder glitches were fixed several days ago. On the first pass after receiving a new set of orbit elements, the SRI team succeeded. As I mentioned in my previous article, the spacecraft appears to still be in good health, and the activities in progress before April (extending the gravity gradient boom, checking out the HF beacon transmitters, TV camera, computers, etc) can continue. Phil Karn, KA9Q