AMSAT-OSCAR-7, A Still Operational, Small-Satellite History Lesson

It has often been reported that the oldest satellites still working in space are, collectively, the JPL 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". This was the alignment of the outer planets, which allowed, using gravitational assist, both Voyagers to visit multiple planets each. Both missions were nothing short of spectacular and they still expand our imaginations. 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 to state that the oldest still working satellite in space wasn't even designed or operated by NASA, USAF, ESA or any other space agency? What if it was stated that this satellite was designed by radio amateurs and the final assembly occurred in a basement laboratory not far from Goddard Space Flight Center? What if it was noted that 2024 is the 50th anniversary of this satellite, launched on 15 November 1974? and, as you will see (and hear) in this paper, the spacecraft, AMSAT-OSCAR-7 (AO-7) is still providing service to hundreds of radio operators around the world, as it has for a very, very long time. And, would you believe that the oldest satellite working around our planet is a SmallSat weighing 29 Kg? The above, as nearly as we can determine, is all true and this is the amazing story of what made this possible and why this satellite os sometimes called the "Sleeping Beauty Satellite." We describe here the story of how the mission was conceived, how radio amateurs from four countries worked together to develop a very complex spacecraft with quite a creative payload. We want to explain the many successes of this communications satellite during its primary mission, and we want to surprise you with the extended mission, which continues to this day. The technology employed by AO-7 was advanced and, in certain aspects, was ahead of the primary spacecraft it flew with (NOAA-4/ITOS-G). We'll tell that story, as well as summarizing other forthcoming special papers relating to the satellite's orbit, power and communications systems and radiation exposure. Time permitting, during the oral presentation of this paper, we will demonstrate the still-functional, robust, telemetry systems and communications transponders aboard AO-7. This is possible, as all these systems can be witnessed using only an audio feed. Much of the telemetry is provided by a very reliable Canadian-provided, 435 MHz beacon transmitter coupled to a novel circularly polarized antenna. We would also like to invite any member of the audience to participate in using AO-7 to do their own experiments as AO-7 moves into the future. AO-7 has already lived longer than many of its designers and operators. It is just possible that it will outlast all of us. - Still in its 1450 km SSO, waiting for the next generation of SmallSat engineers to learn from what it can teach them.

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