Efforts to resurrect the vintage ISEE-3 space probe have ended in disappointment. The probe was launched by NASA in 1978 to measure solar winds, but decommissioned in 1997 as the craft drifted farther and farther from Earth. A group of former NASA employees launched a $160,000 crowdfunding effort in 2008 to attempt to return the probe to active duty, but despite a promising start earlier this week the mission is largely over. The team successfully fired the ISEE-3's thrusters at the weekend, but additional efforts to spin the craft into a new orientation towards Earth have failed.
The promising engine firings over the weekend could have been the result of burned fuel that was already in the fuel lines, but attempts on Tuesday and Wednesday failed because the nitrogen tanks aren't working or are empty. "At this point we're sort of scratching our heads," says Keith Cowing, a former NASA employee working on the project, in an interview with NPR. "We may take one last run at the spacecraft but this may be it for an attempt to bring it back to Earth." The ISEE-3 space probe has now been switched to a mode that allows its instruments to collect and beam back data to Earth. Communications are expected to last around another three months before the craft drifts too far away from Earth to realistically be rescued again.