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ARRL Satellite Bulletin ARLS001 (2006)

ARLS001 "SuitSat-1" keeps on ticking; low power output eyed

QST de W1AW  
Space Bulletin 001  ARLS001
From ARRL Headquarters  
Newington, CT  February 14, 2006
To all radio amateurs

ARLS001 ''SuitSat-1'' keeps on ticking; low power output eyed

''SuitSat-1''--a discarded Russian Orlan spacesuit equipped with ham
radio gear--remains operational more than a week after being
deployed from the International Space Station, but its 145.990 MHz
FM signal continues to be extremely weak copy on Earth. Speculation
now is focusing on extremely low transmitter output power as one
explanation for the faint signal.  SuitSat-1's sponsor--the Amateur
Radio on the International Space Station (ARISS) program--continues
to seek voice telemetry reports as part of an effort to pin down
what might have gone awry.

''The battery life is a big question mark,'' explains ARISS Ham Radio
Project Engineer Kenneth Ransom, N5VHO. ''We still do not know if the
radio is pulling the normal power and losing it before the antenna
or not pulling as much due to lower output. If the latter is true,
the batteries will last much longer. That is one reason the battery
telemetry is so important. It will help us plot the power

Ransom notes that the voice telemetry transmission order is: DTMF
tone, CW ID, SSTV image, 30 seconds of silence, voice
identification, mission time, temperature and battery voltage. The
voice messages, telemetry and SSTV image are being sent on a
nine-minute repeating cycle. Post telemetry reports or recordings to Late reports showed the battery voltage
holding at 26.7 out of a nominal 28 V. The transmitter, albeit
likely at much-reduced output, and the controller appear to be

AMSAT-NA reports its calculations indicate SuitSat-1's transmitter
power likely is in the range of 1-10 mW. The onboard transmitter was
supposed to put out 500 mW and produce a signal that could be copied
on Earth using modest receiving gear and antennas.

The novel SuitSat-1 Amateur Radio transmit-only spacesuit turned
satellite has been heard around the globe since its February 3
launch. Those hoping to get clean copy of SuitSat-1's signal should
possess excellent VHF receiving equipment and high-gain antennas.
AMSAT-NA has designated SuitSat-1 as AMSAT OSCAR 54 (AO-54).

ARRL ARISS Program Manager Rosalie White, K1STO, said the weekend
brought a few reports from teachers who've integrated SuitSat-1
monitoring into their classroom lessons. White notes that the
SuitSat Web site has logged some 5 million hits since the beginning
of February, and media interest in the project remains high.

Packet mode aboard the ISS has been turned off for the duration of
the SuitSat-1 project. Earth stations are advised not to transmit
any packet or voice data on the 145.990 MHz SuitSat downlink

More information on the SuitSat-1 project, including QSL
information, is available on the AMSAT Web site .


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