Amazing. “OSCAR-7” still ALIVE (!)
This satellite is ancient! Batteries died in the early 80s and the thing’s still going on the ancient solar panels. Simply & awesome.
Spacecraft Summary
| OSCAR Designation: | AMSAT-OSCAR 7 | Oscar Number: | AO-7 | ||
| International Designator: | 1974-089B | Norad Number: | 7530 | ||
| Common Name: | OSCAR 7 | Alternate Name: | Phase-IIB | ||
| Satellite Type: | Satellite | Launch Date: | 15 November, 1974 | ||
| Launch Location: | Vandenberg, AFB | Launch Vehicle: | Delta 2310 | ||
| Apogee: | 1459.00 | Perigee: | 1440.00 | ||
| Inclination: | 101.59 | Period: | 114.87 | ||
| Dimensions: | 36.0cm x 42.4cm octahedron |
Weight: | 28.800 Kg | ||
| Organization: | AMSAT-NA | ||||
Amateur Radio had two working satellites in orbit for the first time after OSCAR-7 was launched November 15, 1974. It was a second Phase-2 satellite, similar to OSCAR-6, but with improvements. For instance, OSCAR-7 had two transponders. One received at 146 MHz and repeated what it heard at 29 MHz while the other listened on 432 MHz and relayed the signals on 146 MHz. The latter had an eight-watt transmitter and was built by radio amateurs in West Germany.
In the first satellite-to-satellite link-up in history, a ham transmitted to OSCAR-7 which relayed the signal to OSCAR-6 which repeated it to a different station on the ground.
Australians built a telemetry encoder for the satellite and Canadians built a 435 MHz beacon.
Other beacons were at 146 MHz and 2304 MHz. The 2304 MHz beacon, with a transmitter power of 100 milliwatts, was built by the San Bernardino Microwave Society of California. Unfortunately, the FCC denied the hams permission to turn on their 2304 MHz beacon so it never was tested in space.
OSCAR-7’s radio system worked 6.5 years. Then it stopped functioning.
However, after more than two decades of silence, OSCAR-7’s radio came back to life in 2002.
Both operating modes A and B function, but the satellite’s control system is not working. Even though it can’t be controlled from the ground, OSCAR-7 supports conversations on most passes overhead every day.
The satellite remains in space and it continues to be one of the most enjoyable satellites to use today.