The sad conclusion to the story of NASA's little lost satellite ISEE-3 would make the perfect plot line for a sad Pixar montage.
Launched in 1978, the International Earth-Sun Explorer-3 (ISEE-3) has spent much of the past 36 years circling our star. Traveling just a bit faster than the Earth, always a step ahead, ISEE-3 watched out for us. ISEE-3 kept a close eye on the Sun and reported back. The little satellite helped Earth-bound scientists learn about the great ball of fire at the center of our solar system.
Since ISEE-3 was flying slightly more swiftly than our planet, it was also inching farther and farther away. This year was a chance for a reunion—ISEE-3 was set to catch up from behind, its closest approach in the past 30-odd years.
Unfortunately, more than a decade ago NASA replaced the only transmitters that can talk to ISEE-3. The satellite is still alive, still watching and still sending its helpful messages back to Earth. We could still hear ISEE-3, too, but we had stopped responding. ISEE-3 was alone.
Back in May it started to look like ISEE-3 had a second chance, a new shot at reconnecting with its old friend the Earth. A group of volunteers had rallied to try to try to rebuild the transmitters. On Tuesday, the volunteers reached out to ISEE-3 to say (more or less), "Hey ISEE-3, how's it going? How about we give those engines a burn for old times sake?" ISEE-3 lept in to action! The burn would send ISEE-3 back into Earth's orbit—home, after such a long journey.
On its second and third tries, ISEE-3's engines just wouldn't go. Decades out in space was hard on the little satellite. Out of fuel, or maybe broken, ISEE-3 couldn't muster the one last push that would bring it back to Earth. The volunteers' hands were outstretched, but they were just a little too far away. Dejected, the volunteers packed it in.
ISEE-3 and the volunteers are still talking, still listening. ISEE-3 is still watching the Sun, and still sending its messages back to Earth. With the transmitter rebuilt, ISEE-3 is getting its first conversation in years. But it won't last. With no working engines to burn and still soaring along just a bit faster than the Earth, ISEE-3 will be off again, on another lap around the Sun. Maybe one day it will be back, but by then it will be too late. After another 30 years, whatever energy ISEE-3 has left will be gone for good.