ARLS007 AO-40 Transponder Operation Possible This Summer

[Paul L Rinaldo]

Gang,
FYI
Paul

>SB SPACE @ ARL $ARLS007
>ARLS007 AO-40 Transponder Operation Possible This Summer
>
>ZCZC AS07  
>QST de W1AW  
>Space Bulletin 007  ARLS007
>From ARRL Headquarters  
>Newington, CT  April 27, 2001
>To all radio amateurs
>
>SB SPACE ARL ARLS007
>ARLS007 AO-40 Transponder Operation Possible This Summer
>
>AMSAT-NA President Robin Haighton, VE3FRH, has raised the
>possibility that AO-40 could inaugurate transponder operation this
>summer, if tests and orbital maneuvers between now and then go as
>planned.
>
>''We are learning how to fly this thing,'' Haighton said. ''But I still
>think we're going to end up with a darned good satellite.''
>
>The most likely initial transponder configurations, Haighton said,
>would be Mode L/S--1.2 GHz up and 2.4 GHz down, Mode U/S--435 MHz up
>and 2.4 GHz down, and possibly Mode V/S--145 MHz up and 2.4 GHz
>down.
>
>Recent data suggest that the mid-December incident that silenced
>AO-40 for two weeks and rendered some systems unusable also might
>have blown a hole on the 400-newton motor side of the spacecraft.
>''Speculation is there could be damage, and sunlight is getting right
>in,'' Haighton said. He noted that ground controllers have detected a
>distinct rise in temperature when sunlight strikes that side of the
>satellite.
>
>Ground controllers plan to raise the height of the perigee in the
>very near future, Haighton said. That process, using the onboard
>arc-jet motor, could take up to several weeks. The AO-40 team hopes
>the maneuver will minimize or eliminate possible effects on the
>satellite's orbit caused by atmospheric expansion at the peak of the
>solar cycle.
>
>AO-40 currently is approximately 320 km--almost 200 miles--above
>Earth at perigee--its closest point--and some 51,000 km--some 31,600
>miles--at apogee. Plans call for raising the orbit at perigee to
>around 520 km, or some 320 miles.
>
>Once the orbit has been adjusted, ground controllers would orient
>the spacecraft's attitude and check out the various onboard
>transmitter and receiver systems to see what works and what does
>not. ''We're still pretty confident that the 2 meter and 70 cm
>transmitters are not there,'' Haighton said, ''but we're equally
>confident that the receivers for those bands still are.''
>
>The satellite has been transmitting telemetry on the 2.4 GHz (S-2)
>beacon, and signals reportedly have continued to improve--although
>the beacon has been out from time to time as needed to conserve
>power during eclipse periods.
>NNNN
>/EX
>