Weak Signals Heard from Spanish Satellites EASAT-2 and HADES
From ARRL de WD1CKS@VERT/WLARB to QST on Tue Jan 25 13:34:50 2022
AMSAT-EA (Spain) has said it appears that EASAT-2 and HADES are transmitting, and that weak signals have been heard, but the satellites' antennas may not have deployed.
"We confirm the reception of both EASAT-2 and HADES, as well as the decoding of telemetry and the FM recorded voice beacon with the call sign AM5SAT of the first one. EASAT-2 appears to be working well, except for the deployment of the antennas - something that apparently has not yet occurred and causes weak signals," said AMSAT-EA Mission Manager Felix Paez, EA4GQS. "However, the AMSAT-EA team confirms that, based on the reception of FSK, CW, the FM voice beacon, and the telemetry data that has been decoded, it can be said that the satellite is working perfectly. In the event of low battery or system malfunction, the onboard computer would not transmit CW messages or the voice beacon call sign, as it would be in [safe mode] with only fast and slow telemetry transmissions."
At the request of AMSAT-EA, EASAT-2 has been designated as Spain-OSCAR 114 (SO-114) and HADES as Spain-OSCAR 115 (SO-115).
"These signals that confirm the operation of both satellites were received by Daniel Estévez, EA4GPZ, at 1807 UTC on Saturday, January 15, using two antennas from the Allen Telescope Array." Doppler observations from the co-launched Delfi-PQ satellite and the amateur radio community have been used to identify the satellites' orbits or TLEs.
AMSAT-EA reports that Estévez performed a preliminary analysis using just one polarization of one of the Allen Telescope Array satellite dishes. EASAT-2 was detected with a relatively strong signal, close to the Delfi-PQ signal, obtaining voice FM beacon transmissions and FSK, FSK-CW at 50 baud, AMSAT-EA said.
"The CW beacon clearly shows the message VVV AM5SAT SOL Y PLAYA, which is one of several that both satellites emit, although the call sign AM5SAT confirms that it is EASAT-2," AMSAT-EA said. "In the recording made by EA4GPZ, there is also a faint trace confirmed to be from HADES and stronger packets probably from the IRIS-A satellite."
AMSAT-EA reports that signals from HADES are weaker than those of EASAT-2, "most likely because the onboard computer has not yet managed to deploy the antennas either, although it will continue trying regularly," AMSAT-EA said. "The reason the signals are suspected to be weaker at HADES is that the antennas are more tightly folded than those of EASAT-2. In any case, this is great news, since the transmission pattern confirms the proper functioning of the satellite. In the observations, you can see the FSK tones with a deviation of about 5 kHz interspersed with the FM carrier corresponding to the voice beacon of the satellite, which has call sign AM6SAT. The AMSAT-EA team is working to try to decode the telemetry signals and obtain more detailed information on the state of the satellite."
AMSAT is asking amateurs with "very high-gain antennas" to try to receive them - especially HADES. "If we could decode telemetry, it would be very helpful for us." AMSAT-EA said. "Until antennas are deployed, it will be very difficult to use their repeaters or to receive any SSTV camera images from HADES, but we hope that this will happen sooner or later, at least because, even if the computer doesn't succeed applying heat to the resistor where the thread [retaining the antennas] is attached, with time, the thread should break due to the space environment conditions." - Thanks to AMSAT News Service