An American satellite abandoned in 1967, now assumed to simply be space junk, has started transmitting again after 46 years.
This was one of the satellites designed and built by Lincoln Laboratory at MIT between 1965 and 1976, for testing techniques for satellite communication.
They made the series of satellites easy to recognize by naming them LES1 through to LES9. LES1-LES4 suffered different launch issues. LES1 and LES2 were supposed to be delivered to the same 2800 x 15000 km orbit, but a failure of a boost stage left LES1 in a 2800 km circular orbit.
LES3-LES4 were supposed to land in geostationary orbit, but didn’t make it due to a launch problem which left them in transfer orbit. Even though the first four satellites in the series ended up in the wrong orbits, they all produced remarkable results.
In 2013 in North Cornwall, UK, an Amateur Radio Astronomer picked up a signal which he determined to be the LES1 that was built by MIT in 1965. The satellite never made it to its intended orbit and had been spinning out of control ever since.
Phil Williams, the amateur radio astronomer from near Bude, picked out the odd signal which was transmitting due to it tumbling end over end every four seconds as the solar panels became shadowed by the engine. “This gives the signal a particularly ghostly sound as the voltage from the solar panels fluctuates,” Williams said.
It’s more than likely the onboard batteries have disintegrated, and something else caused its 237Mhz transmission to resume when it was in sunlight.
The LES1 is about the size of a small automobile and should not cause any issues more than any other piece of space junk in orbit.
It proves electronics built around 50 years ago, 12 years before Voyager 1, and far before microprocessors and integrated circuits are still capable of working in the hostile environs of space. Phil refers to his hobby as “Radio-Archaeology”.
LES1 and LES2 were almost identical experimental communication satellites. They both had a single X-band transponder and an 8-horn electronically switched antenna. Altitude control and sensing experiments were conducted on these twin satellites.
Their first project initiative was to build, launch, and field a system to show off practical military satellite communications. Project West Ford’s availability for the advanced super-high-frequency (SHF) technology (at seven-to-eight gigahertz) contributed to the decision to design the system for that band.
The concurrent procurement of a series of satellites and terminals for the Department of Defense that commenced with the Initial Defense Communications Satellite Program (IDCSP) meant lessons were learned from the experiments would find an additional application.
On February 11, 1965, LES1 was launched from Cape Canaveral but only accomplished a few of its objectives. It seems miswiring of the satellite circuitry was what caused it to never leave the circular orbit and it stopped transmitting in 1967. LES2, the twin of LES1, did much better; it made its planned final orbit on May 6, 1965.