SuitSat-1 is now a confirmed "Silent Key." So says its sponsor, the Amateur Radio on the International Space Station (ARISS) program. In operation for more than two weeks, SuitSat-1--designated AO-54--easily outlasted initial predictions that it would transmit for about one week. ARISS International Chairman Frank Bauer, KA3HDO, says the mission captured imaginations around the world, despite a much-lower-than-expected signal strength.
"The outreach, press requests and visibility of SuitSat were absolutely amazing and appear to be unprecedented for a ham radio event," Bauer said. "While the press requests are just now starting to wane, we expect that you will continue to see SuitSat status reports and pictures in magazines, Web sites and other literature over the next few months." The more than nine million hits at the SuitSat Web site attest to the level of interest in the SuitSat-1 experiment, Bauer noted, calling the tally "quite impressive indeed!"
Bob King, VE6BLD, in Alberta posted the last confirmed reception of SuitSat-1's voice audio, Saturday, February 18, at 0332 UTC. Richard Crow, N2SPI, in New York received the last confirmed telemetry, which indicated the battery voltage dropping precipitously to a low of 18.3 V before the novel satellite ceased to transmit.
Hearing SuitSat-1's puny signal strength generally required gain antennas, but Bauer says he heard SuitSat with a 3-element Arrow antenna and a handheld radio. Bauer's daughter Michelle recorded the English-language voice identification. Another challenge to signal reception, he said, was the very deep fading due to the suit's rotation in orbit.
"One great positive that came from these issues is that it challenged the ham radio community worldwide to improve their station receive capabilities so that they could pull every bit of signal from SuitSat," Bauer remarked.
Bauer says reports that SuitSat-1 was non-operational and that the battery was frozen shortly after deployment are false. "This never occurred," he stressed. "As the telemetry has shown, temperatures within the suit were a somewhat comfortable 12-16 degrees C during the entire mission."
So, he adds, is the tale of SuitSat-1's early demise and resurrection. "It was alive and operated flawlessly, except the signal strength issue, from the time the crew flipped the switches until the battery power was used up," he said.
Bauer says he's also not ready to buy into an AMSAT calculation that the transmitter may have been putting out between 1 and 10 mW. "It is entirely possible that the radio output could have been at 500 mW, and the feed line, connector or the antenna caused the problem," he said, adding that the SuitSat team has only just begun studying what might have caused the weak signal.
The AMSAT/ARISS team already is looking forward to a SuitSat-2. "Correcting the signal strength issue would be a top priority for this flight," Bauer said. "So would be a longer-term power generation device, like solar arrays."
Although no longer transmitting, SuitSat-1 could continue orbiting Earth for another 70 to 120 days, depending on atmospheric drag, Bauer said.
More information on the SuitSat-1 project, including QSL information, is available on the AMSAT Web sitehttp://www.amsat.org/ and on the SuitSat Web site http://www.suitsat.org/.
The ARRL Letter Vol. 25, No. 08 February 24, 2006