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WG3K > ANS 03.11.24 17:34l 19 Lines 2636 Bytes #132 (0) @ AMSAT
BID : ANS308.1
Read: GUEST
Subj: AMSAT AO-7 to Celebrate 50th Anniversary
Path: IZ3LSV<DB0ERF<DK0WUE<DK0WUE<VK5RSV<VK2RZ<KC9UHI<KA1VSC<WG3K
Sent: 241103/1632Z 9770@WG3K.#SMD.MD.USA.NOAM LinBPQ6.0.24
It has often been reported that the oldest satellites still working in space are the space probes Voyager 1 and Voyager 2. The Voyagers were both launched in 1977 to take advantage of the planetary alignment called, back then, the “Grand Tour”. Their images changed the human vision of our solar system.
But, are they really the oldest, still functional spacecraft in outer space? What if we include spacecraft that remained behind in Earth Orbit? Is it even believable that the oldest still working satellite in space wasnt even designed or operated by NASA, USAF, ESA or any other space agency? What if this satellite was designed by Radio Amateurs and the final assembly occurred in a basement laboratory not far from Goddard Space Flight Center?
Then all things considered, AO-7, a SmallSat launched on November 15, 1974 is the oldest working satellite and is still providing service to hundreds of Amateur Radio operators around the world. In its first life, AO-7 lived a very healthy lifetime of 6.5 years. Not to over-state the case, AO-7 outlived both its commercial and government co-passengers launched by Delta-104.
In late 1980, AO-7s poor, abused, NiCad battery began to show serious signs of increased series resistance. This was a sure sign to AMSAT command stations that the end was in sight. The cells had been originally matched for capacity by NASA. And, indeed the cells all failed within a matter of weeks of one another.
AO-7 stayed asleep for 21 years, to the nearest month. Then one day AO-7 woke up again. This was only possible if something caused an open circuit in the battery.
A very active user of AO-7, Pat Gowain, G3IOR, from the UK, made a telephone call to Perry Klein, W3PK, (first AMSAT President and designer of the VHF/HF transponder). This was on June 21, 2002. Pat wondered if we had launched a new LEO spacecraft? He was hearing Morse Code Telemetry again on the old beacon frequency of AO-7. He played Perry a tape recording. It sure sounded like AO-7 telemetry!
Many radio amateurs who were satellite enthusiasts very quickly began to observe the signals from AO-7 and the second life of the "Sleeping Beauty" of satellites began.
Over the next three weeks in November AMSAT News Service will honor this historic achievement with a series of short articles highlighting the life of AMSAT OSCAR 7. In the meantime be sure to visit a special page on the AMSAT website where you will find a collection of AO-7 articles and links at https://www.amsat.org/amsat-ao-7-a-fifty-year-anniversary/.
[ANS thanks Jan King, W3GEY, AMSAT AO-7 Project Manager for the above information.]
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