The quest to save the ISEE-3—a long-lost NASA probe launched in the disco era and abandoned in the dot-com boom—might just succeed. Late last week, the amateur scientists and engineers working to salvage the probe hit a major milestone: They coaxed the craft into firing its rotational thrusters.
The achievement is important for many reasons. While the amateur team trying to reboot the ISEE-3 has been in radio contact with the probe for more than a month, this is the first time it has successfully commanded moving parts onboard. It’s important for technical reasons. The ISEE-3 is “spin-stabilized,” meaning it only functions properly when it’s tumbling over itself. The team can now adjust that spin.
And, finally, it’s important for planning reasons. Now, the team can begin to fire the ISEE-3’s thrusters and change the ship’s trajectory—hopefully, keeping it from crashing into the moon.
Keith Cowing, a journalist-turned-mission-leader, told me that they hoped to begin changing its course on Tuesday. “We’re pretty much confident now that it’ll come close to the moon but not crash into it,” he said.
Launched in 1978, the International Sun/Earth Explorer-3 first served for years as a solar observatory, sitting at a stable orbit point between the Earth and the Sun. By 1986, NASA had replaced the aging craft with superior sensors. They determined it didn’t need to occupy its stable position, so they piloted it through the tails of Comet Giacobini-Zinner and Halley’s Comet. The ISEE-3 was renamed ICE, the International Comet Explorer.