ARRL

ARRL Satellite Bulletin ARLS002 (2003)

SB SPACE @ ARL $ARLS002
ARLS002 AO-27 orbit affecting operating periods

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Space Bulletin 002  ARLS002
From ARRL Headquarters  
Newington, CT  January 23, 2003
To all radio amateurs

SB SPACE ARL ARLS002
ARLS002 AO-27 orbit affecting operating periods

According to AMSAT-NA, several stations recently have reported
hearing AO-27's transponder on the air at unexpected times. AO-27's
orbit has moved the satellite into a period of full-orbit solar
illumination, explained Mike Seguin, N1JEZ. Because of this, the
timed eclipse power regulator (TEPR) method of timing the
transmitter does not work. As a result, AO-27's transmitter can only
be turned on by ground-station command.

Seguin said controllers will try to turn AO-27 on for analog work
during weekends, when controllers are not downloading telemetry.
Right now, however, controllers are working on new flight software
that will permit uploading a transmitter schedule for the
transmitter.

"This will take us some time to write, debug, and upload to AO-27,"
he said. Seguin requested that operators be patient during this
process and refrain from e-mails to AO-27 command stations asking
when the satellite will be on. Seguin noted that during seasons of
full-orbit solar illumination, controllers will be able to have
AO-27's transmitter on at night and for different parts of the
world.
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