- The Washington Times - Sunday, July 28, 2002

A satellite built by amateur radio operators has come back to "life" 21 years after it was declared dead.
The Oscar-7 satellite (Orbiting Satellite Carrying Amateur Radio) was launched Nov. 15, 1974, and remained in operation for about six years before its batteries failed.
That was expected one of the commonest causes of satellite failure is battery failure and Oscar-7 became one of thousands of pieces of Earth-orbiting space junk.
Nobody expected to hear from Oscar-7 again, until amateur radio operator Pat Gowen happened to be monitoring VHF frequencies on June 21.
"I have just come across something most remarkable," he said, and described a signal identical to what Oscar-7 transmitted when operational.
Several others verified what Mr. Gowen heard Oscar-7 was apparently transmitting again after more than two decades of silence but only when the satellite was being illuminated by the sun.
The amateur radio operators who built Oscar-7 have theorized that over time as the satellite passed back and forth between sunlight and darkness 12.5 times each day, some chemical change occurred in the batteries, clearing the short circuit.
The sun didn't bring the batteries operational again, but it stopped their lack of power from being in the way, similar to being able to use an adapter to operate a portable cassette player with dead batteries.
"I'm blown away," said Jan King, the original project manager. "So, this old warhorse of a spacecraft seems to have come back from the dead, if only for a few moments."
Oscar-7 was built in the early 1970s in the basement of Mr. King's house in Lanham, using a pool table as a workbench.
Amateur radio operators have built satellites since almost the beginning of the space program. The first Oscar was launched Dec. 12, 1961, along with one of the early U.S. spy satellites, Corona 36.
Hobbyists build amateur radio satellites using some donated aerospace-quality components Oscar-7's battery was a NASA-donated spare. But mostly, the builders make creative use of use off-the-shelf parts, such as using $3 retractable tape measures for antennas.
Launches are obtained on a "piggyback" basis where a major organization launching another satellite donates excess capacity on its rocket. For Oscar-7 the primary payload was a weather satellite.
The few moments have turned into a month with no end in sight. Some of the people involved with Oscar-7's construction cautiously note that since the electronics and solar cells have lasted this long in the space environment the satellite should continue to operate.
Without a working battery, Oscar-7 is similar to a computer with a nonworking clock battery. Each time Oscar-7 comes into sunlight it comes up in a random mode, with one of its three transmitters running, but not what it's supposed to do.
Nevertheless, many amateur radio operators have listened to Oscar-7's signal and successfully contacted others through the satellite. The 30-year-old electronics still work and in theory any amateur radio operator with a handheld radio can receive its signal.
Oscar-7 has made more than 1.2 million orbits around Earth in its 28 years in space.


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