ARRL

ARRL Satellite Bulletin ARLS025 (2000)

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.
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/EX