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![Previous (earlier) Story](/images/sty-down.gif ""SuitSat-1" is Now AO-54; Reports Persist of Weak Signals"){kind=small} Previous: "SuitSat-1" is Now AO-54; Reports Persist of Weak Signals |  Next: Phil Salas, AD5X, Named 2005 Orr Award Winner |
 Prior to launch, ISS Expedition 12 Flight Engineer Valery Tokarev stuffs SuitSat-1 with its Amateur Radio payload. Tokarev later released SuitSat-1 into space during a February 3 space walk. |
 SuitSat-1, backdropped by the blackness of space and Earth's horizon. The unusual satellite will enter the atmosphere and burn up in a few weeks. [NASA Photo] |
 ISS Commander Bill McArthur, KC5ACR, at the helm of NA1SS. McArthur has said he's been unable to copy the SuitSat-1 signal from the ISS. [NASA Photo] |
 A.J. Farmer, AJ3U, listens for SuitSat-1 from his Maryland backyard. Farmer has set up a Web site to collect audio clips from SuitSat-1. |
 Bob King, VE6BLD, in Alberta--shown here with his extensive antenna system--has posted several SuitSat-1 reports. |
NEWINGTON, CT, Feb 8, 2006--Based on recent reports, the already-puny 145.99 MHz signal from "SuitSat-1" may be getting even weaker, but at least one earthbound radio amateur has been able to copy a very nearly complete telemetry transmission. ARRL member Richard Crow, N2SPI, of Smithville Flats, New York, heard the SuitSat-1 audio during a February 8 pass at approximately 1350 UTC. The recording indicated a reasonably strong signal between fades.
"Yippee!," Crow exulted in a posting on the Web site of A.J. Farmer, AJ3U, who's been collecting SuitSat audio clips. "I just captured the telemetry for SuitSat-1." Between fades because of SuitSat-1's rolling, the telemetry in a woman's voice clearly gives the mission time as 006607 minutes, the temperature as 12 degrees Celcius and the battery voltage as approximately 26 V. A signal fade during the voltage transmission made it impossible to hear the fractional part of the voltage reading after the word "point" to indicate the decimal point. The nominal battery voltage is 28 V, so the telemetry Crow copied suggests the batteries are not the problem behind SuitSat-1's generally weak signal.
Crow also copied a voice ID and other information in Russian. "My four stacked M2 2m12 antennas are bringing home the bacon!" Crow said he also was able to download "some pretty decent SuitSat-1 image data" that he may post later to the AJ3U site. He already submitted SSTV audio. The space image includes the logo of SuitSat-1's sponsor, the Amateur Radio on the International Space Station (ARISS) program, in the upper-left corner and has some text superimposed on the bottom of the frame.
Farmer, who lives in Maryland, has invited the Amateur Radio and monitoring communities to post audio clips to site.
ARISS Invites Telemetry Reports
SuitSat-1's voice ID, "This is SuitSat-1, Amateur Radio station RS0RS," is transmitted in several languages. There's also a CW ID that reportedly says "Spacesuit-1" instead of "SuitSat-1." SuitSat-1 also is transmitting a single slow-scan TV image.
ARISS remains very interested in obtaining any valid voice telemetry reports (post to SAREX@amsat.org). "The telemetry is transmitted about 30 seconds after the SSTV image stops," explains ARISS Ham Radio Project Engineer Kenneth Ransom, N5VHO. Ransom says the transmission order is SSTV image, 30 seconds of silence, voice identification, mission time, temperature and battery voltage. "The battery voltage is of most importance," he added.
Dirty Laundry
The unusual Amateur Radio transmit-only satellite, which consists of a discarded Russian Orlan spacesuit equipped with ham radio gear, was released February 3 by International Space Station (ISS) Expedition 12 Flight Engineer Valery Tokarev as he and Expedition 12 Commander Bill McArthur, KC5ACR, began a six-hour spacewalk. The crew stuffed some of its laundry into the spacesuit to help it to keep its form as it orbits Earth. Over the weekend, AMSAT-NA officially designated SuitSat-1 as AMSAT OSCAR 54 (AO-54).
"Congratulations are in order to Frank Bauer, KA3HDO, Sergey Samburov, RV3DR and the entire Radioskaf/SuitSat team for mounting this exciting and attention-getting project," said AMSAT-NA's Bill Tynan in announcing the AO-54 designation. "Seldom has an Amateur Radio event captured the public's imagination and evoked so much positive news media coverage as SuitSat has."
Signals Heard on Earth Generally Weak
Tony Hutchison, VK5ZAI, in Australia, this week reported that on its second pass over his location February 6, SuitSat's signal was down.
"It appeared that signals had deteriorated since yesterday on both passes," said Hutchison, who's the ARISS Australia coordinator. "It may be the angle that SuitSat was when it passed, but on yesterday's passes it was possible to detect it rolling," Hutchison continued. "I did detect voice this last pass, but it was well down in the noise, and I didn't hear any SSTV this last pass."
Bob King, VE6BLD, in Alberta, who's managed to copy SuitSat fairly well on several passes, also noted that the signal's strength had declined from what it was during the previous two passes he'd heard. King says he's using an FT-847 transceiver with the preamplifier on and a 22-element crossed Yagi with right and left circular polarization providing 19 dB of gain. A preamp at the antenna feeds into half-inch hardline to the shack.
"The bird was almost overhead, so the signals were about S6 when clear," he reported over the weekend. "I also received the SSTV signal with some noise."
Heard Around the World
SuitSat-1's very weak VHF signal notwithstanding, reports have come from stations and listening posts literally around the globe. ARISS International Secretary Rosalie White, K1STO, reports the ARISS Team was continuing to receive files containing some SSTV audio as well as snippets of voice and CW. "You can hear deep fades in the signal as the suit spins--something we learned from this experiment," she said. "The team is coming up with ideas including things that students can do with all the data we collect from recordings, such as looking at spin rate and transmission fading." 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.
Keplerian Elements
Farmer reported early this week that SuitSat-1's orbit was some two miles below and one minute ahead of the ISS's. He has provided updated Keplerian elements for use in satellite tracking software:
1 28933U
05035C 06037.71475917 .00035749 00000-0 23912-3 0 73
2 28933
51.6466 138.4761 0007647 243.6705 116.3893 15.74902159 437
SuitSat-1 Reports via NA1SS Crossband Repeater Discounted
Several reception reports on the SuitSat Web site indicate SuitSat-1 audio has been retransmitted via the NA1SS crossband repeater aboard the ISS. While the NA1SS Phase 2 station has been configured to retransmit SuitSat's 145.99 MHz signal on 437.800 MHz, Ransom says he tends to discount the validity of the signals heard on UHF.
"Be very careful about reports via the UHF repeater," he cautions. "Since it hears everything, people are reporting every little squeak and whistle." He says ARISS activated the VHF-to-UHF crossband repeater as part of a "just-in-case" philosophy, and any reports posted are "very hard to verify" at this stage.
"To my knowledge, Bill McArthur has not heard SuitSat from the ISS," he adds, "so it stands to reason that the crossband relay has not either."
Several reports mention hearing packet signals, but SuitSat-1 carries no packet gear. All telemetry transmissions are by digital voice. Ransom believes that voice signals heard via the crossband repeater on UHF are "most likely" coming from ground stations.
Likewise, the packet bursts are emanating from "uninformed ground stations" trying to relay via the ISS digipeater, which has been turned off, Ransom and Farmer speculate. Ransom again urged all Earth stations not to transmit on SuitSat-1's 145.99 MHz frequency--which is also the normal packet uplink channel--until the SuitSat-1 experiment ends.
ISS Commander Discusses SuitSat-1 During Series of QSOs
During a series of VHF contacts from NA1SS following the spacewalk, Expedition 12 Commander McArthur expressed surprise that was unable to hear SuitSat-1 from the ISS shortly after coming inside from the spacewalk. He initially believed the unique satellite was dead.
"We should have been pretty close but didn't hear anything," he told one station. Scott Avery, WA6LIE, provided downlink audio of the QSOs.
What Went Wrong?
Some early speculation about SuitSat-1's difficulty has centered on whether SuitSat-1's batteries might somehow have been adversely affected by the temperature extremes of space. In another post-spacewalk QSO, McArthur expressed some doubt about that theory
"It's the same battery we use in our spacesuits," McArthur told one station, "and so I would think they would handle the temperature, but it's hard to say." McArthur noted that the batteries on an Orlan spacesuit are in an external compartment that's already exposed to the harsh space environment.
McArthur also remained upbeat about a future SuitSat mission. "Where there's a will there's a way," he philosophized. "We've got more suits that need to be jettisoned." He said the SuitSat-1 project "was pretty well set up and wasn't that difficult for us to execute."
Ransom believes the problem was likely present from the beginning of the SuitSat-1 mission. He noted that premature media reports of SuitSat-1's demise were based on a lack of reports for several orbits.
"Little did we know that the output was so diminished," he
said. "It is now apparent that everything is functioning, but that the output
level is extremely low." He expressed hopes that additional telemetry would "help
support or dismiss the current list of potential causes for the low output" and
help ARISS to pin down the problem's cause.
ARISS Chief Remains Optimistic
ARISS International Chairman Frank Bauer, KA3HDO, said over the weekend that evidence to that point in the mission suggested a problem with the antenna, the feed line, the transmitter output power "and/or any of the connections in between." Bauer called on stations around the world to help narrow down what's causing the weak signal by making an extra effort to listen for SuitSat-1 on 145.99 MHz and especially to copy the voice telemetry.
Early on February 4, Bauer was able to hear one overhead pass that included at least part of the English-language ID, recorded by his daughter, Michelle. "Keep your spirits up, and let's continue to be optimistic," he urged later in an official SuitSat-1 status report. "And please keep monitoring!"
More
information on the SuitSat-1 project, including QSL information, is
available on the AMSAT Web site.
| Previous: "SuitSat-1" is Now AO-54; Reports Persist of Weak Signals | Next: Phil Salas, AD5X, Named 2005 Orr Award Winner |
