A NASA spacecraft launched in 1978 has finally run out of fuel. The International Sun-Earth Explorer 3 (ISEE-3) is currently trying to be diverted back into its original orbital path after it was manipulated by Robert Farquhar in 1983.
Farquhar, a former NASA employee, disregarded the space agency's orders back in 1983 and diverted ISEE-3's orbital path. Oddly enough, the blatant transgression earned him a congratulatory letter from then-president Ronald Reagan. Farquhar took the ISEE-3 out of its orbital path while it was studying solar winds and had it intercept the Giacobini-Zinner comet, making the United States the first country to achieve such a feat. NASA wasn't focusing on such a mission because they said it was too expensive.
But Farquhar promised NASA he would get the satellite back - 30 years later, when it was scheduled to come back near Earth. He and a team of scientists started a crowdfunded project to raise money in an effort to reestablish contact with the ISEE-3, reboot it, and get it back into its original orbital path. They managed to receive signals from the spacecraft, which was reported to be in excellent working order, but members of the project said on Thursday that it has ran out of fuel.
"Is this what we planned on? No," Keith Cowing, leader of the ISEE-3 Reboot Project, said in a phone interview with NBC News. "But we have so many other options for using the spacecraft, no way are we shutting this thing off. We haven't given up hope on the propulsion system."
The team believes that the nitrogen used to pressurize the satellite's fuel system has been exhausted and they're now looking for new ways to utilize the 36-year-old ISEE-3. But the 81-year-old Farquhar is not so sure it can be salvaged. He said without working thrusters there's no way ISEE-3 can survive much longer. But the team will attempt to turn its heaters on, which they believe could increase the pressure high enough to ignite another pulse for the propulsion system.
The scientists need to act fast because the satellite is expected to pass close to Earth on August 10. However, it's very possible that the team will bid farewell to the valiant spacecraft if their final efforts don't prove successful.
You can read more about the ISEE-3 in this NPR article.
