07.01.2001 11:59:50
Источник: Александр Ковалевский
ZCZC AS01 QST de W1AW Space Bulletin 001 ARLS001 >From ARRL Headquarters Newington, CT January 4, 2001 To all radio amateurs
SB SPACE ARL ARLS001 ARLS001 AO-40 Recovery Continues
Efforts continue to assess the status of AO-40 following a resumption of telemetry transmissions. AO-40 went silent December 13, but ground controllers successfully reset the main computer on Christmas Day and got the satellite transmitting again.
Ground controllers now are analyzing the telemetry sent via the S2 beacon on 2401.305 MHz. AMSAT-NA President Robin Haighton, VE3FRH, says the command team worked through the holidays in an effort to determine just what went wrong aboard AO-40. Among other things, ground controllers would like to know what actually happened on December 13 and why, as well as which telemetry functions are known to be correct and which data are suspect and why. The satellite went silent during maneuvers to test its onboard 400-Newton propulsion system following an earlier orbit-shifting burn.
Ground controllers also want to know the spacecraft's actual attitude with respect to Earth--and if it has changed attitude. Other parameters they'll be examining include spin velocity, the status of batteries, battery chargers and regulators, and what happened to the onboard computers, IHU-1 and IHU 2, and why.
The AO-40 command team also wants to find out if all the antennas are operational and what can be done next to improve communications, and if there are any risks involved in attempting to restart onboard systems. So far, the 2-meter beacon transmitter has remained off the air since AO-40 was returned to ground control on Christmas Day. It's believed that problems with the 70-cm transmitter developed shortly after launch. The 2.4 GHz transmitter appears to be operating ''nominally,'' however.
''When questions such as these--and others--are answered, it may be possible to determine the working capability of the spacecraft, and, if appropriate, to start to try operation on other bands,'' Haighton said. He said critical decisions will be made over the next week or two ''based on the results of the analysis and much discussion among the command team.'' NNNN /EX
* Origin: ---=== RA9LO Station at MO27SC ===--- (2:5077/39) --------------------------------------------------------------------
Alexander
RZ6HGG Stavropol E-mail:rz6hgg@skiftel.ru FidoNet: 2:5064/11.30 7 января 2001 г. 8:01:20