More than 30 years ago, Robert Farquhar stole a spacecraft.
Now he's trying to give it back.
The green satellite, covered with solar panels, is hurtling back toward the general vicinity of Earth, after nearly three decades of traveling in a large, looping orbit around the sun.
If Farquhar, a former mission design specialist for NASA, gets his way, the agency will command the spacecraft to fire its thrusters, veer close to the moon, and slip back into the spot where it was intended to be when it was launched in 1978 — and where it was when Farquhar and his accomplices "borrowed" it.
Back in the 1980s, space agencies were racing to Halley's Comet. But NASA wasn't going — officials said a comet mission was too expensive. That did not sit well with Farquhar, who had dreamed of achieving the first comet encounter ever.
So he figured out how to divert an existing satellite, called the International Sun-Earth Explorer (ISEE-3), that was stationed between the Earth and the sun in an innovative halo orbit that he had pioneered.
Farquhar came up with a complicated trajectory that would let this spacecraft intercept a different comet called in September of 1985, months before the armada of other space probes would arrive at Halley's.
"We beat all the other countries of the world," recalls Farquhar. "The European Space Agency. The Russians. The Japanese."
President Reagan even sent him a congratulatory letter.
But some of the scientists who'd been using ISEE-3 to study things like solar wind were not amused by the comet caper.
"They thought that — it was in the newspapers, even — that we stole their spacecraft," says Farquhar. "We didn't steal it; we just borrowed it for a while! That's what I tried to tell them."
Read more: "Space Thief Or Hero? One Man's Quest To Reawaken An Old Friend"