Update: NASA confirms amateur astronomer has discovered a lost satellite

*Update, 31 January, 11:20 a.m.: On 30 January, NASA confirmed that Tilley had discovered the revived IMAGE satellite. The NASA team was able to “read some basic housekeeping data,” the agency said, suggesting that at least the main control system is operational. Efforts to command IMAGE will likely take another week or two, as the satellite’s old control software is adapted to modern systems.

Here is our original story from 26 January:

After years in darkness, a NASA satellite is phoning home.

Some 12 years since it was thought lost because of a systems failure, NASA’s Imager for Magnetopause-to-Aurora Global Exploration (IMAGE) has been discovered, still broadcasting, by an amateur astronomer. The find, which he reported in a blog post this week, presents the possibility that NASA could revive the mission, which once provided unparalleled views of Earth’s magnetosphere.

The astronomer, Scott Tilley, spends his free time following the radio signals from spy satellites. On this occasion, he was searching in high-Earth orbit for evidence of Zuma, a classified U.S. satellite that’s believed to have failed after launch. But rather than discovering Zuma, Tilley picked up a signal from a satellite labeled “2000-017A,” which he knew corresponded to NASA’s IMAGE satellite. Launched in 2000 and then left for dead in December 2005, the $150 million mission was back broadcasting. It just needed someone to listen.

After Tilley revealed the discovery, word rocketed around to former members of IMAGE’s science team, says Patricia Reiff, a space plasma physicist at Rice University in Houston, Texas, who was a co-investigator on the mission. “The odds are extremely good that it’s alive,” Reiff says. There also appear to be data beyond telemetry in the signal, perhaps indicating some of the satellite’s suite of six instruments are working.

Since Tilley’s announcement, project scientists spent a couple days furiously digging up old software and records, and this weekend, NASA will attempt to contact IMAGE with its deep space radio antennas—as will the Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland, and researchers at the University of California, Berkeley. Right now, the team is puzzled as to why it appears the spacecraft’s rotation rate has slowed, which may make communication more challenging. “The team is collectively holding their breath waiting for some real information exchange between IMAGE and the ground,” Reiff adds.

Prior to its failure, IMAGE was already considered a successful mission. The half-ton satellite’s instruments served as a sort of telescope, providing a global view of charged particles captured in Earth’s magnetic field. IMAGE’s instruments captured energetic neutral particles ejected by collisions of atoms in the inner magnetosphere, creating a broad-scale picture of that region and its interactions with the sun. It’s a capability that has never been replaced, Reiff says. “It is really invaluable for now-casting space weather and really understanding the global response of the magnetosphere to solar storms.”

During its extended mission, however, IMAGE’s signal winked out just before Christmas in 2005. The mission had been working perfectly up to that point; NASA eventually attributed the loss to a misfire of the controller providing power to the satellite’s transponder. It remained possible, however, that IMAGE could reset itself during points in its orbit when Earth eclipsed its solar panels for an extended time, draining its batteries. Such eclipses occurred last year—and 5 years ago—perhaps triggering its rebirth.

If IMAGE is revived, its orbit will be well positioned to monitor Earth’s northern auroral zone. It’s thrilling to think the spacecraft could be back, Reiff adds. It reminds her of the mission’s motto: “The real voyage of discovery is not in seeking new landscapes, but in having new eyes.”