SB SPACE @ ARL $ARLS025 ARLS025 AO-40 Beacon Goes Silent ZCZC AS25 QST de W1AW Space Bulletin 025 ARLS025 From ARRL Headquarters Newington, CT December 14, 2000 To all radio amateurs SB SPACE ARL ARLS025 ARLS025 AO-40 Beacon Goes Silent AMSAT reports there's a problem aboard AO-40. The Amateur Radio satellite has not been heard from since December 13. AMSAT says the AO-40 development team is looking into the problem, but it might not have any answers until December 16. That's when the onboard computer is expected to automatically reset itself and, it's hoped, restart the beacon transmission. AMSAT-NA President Robin Haighton, VE3FRH, said the problem may or may not be related to earlier difficulties getting AO-40's 400-Newton motor to fire properly. Ground controllers adjusted the satellite's orbit earlier this week, but as a result of fuel-valve problems, AO-40 ended up in a higher-than-planned orbit. AMSAT reports that 2-meter telemetry transmissions from AO-40 stopped early Wednesday, December 13, while work on the 400-Newton propulsion system was in progress. ''A lot of people are putting their heads together,'' Haighton said, but until the telemetry transmission reappears, not much will be known. ''It's very frustrating,'' he said. AMSAT says onboard software events set to occur Saturday afternoon are programmed to start a spacecraft emergency routine called ''command-assist'' that attempts to re-establish communication. Once communication is re-established, AMSAT says, ground controllers will have their best chance to recover any evidence of the incident that made the telemetry transmissions stop. Monitors around the world are listening for any signal from AO-40 on the 145.898 MHz beacon frequency. NNNN /EX