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NASA confirms: Its undead satellite is operational

Next up: Trying to figure out which of the science instruments still works.

IMAGE being prepared for launch.
Enlarge / IMAGE being prepared for launch.

Late last month, news broke that a satellite sleuth had spotted what appeared to be a lost NASA probe alive and sending out data. Now, NASA has officially confirmed the identity of the satellite as the IMAGE orbiter and is in the process of restoring the capability of processing the data that it is sending down. While we don't yet know whether any of its instruments are operational, one of its original team members is arguing that the hardware can still produce valuable science.

And NASA has determined that the craft's return to life is even more mysterious than we'd realized. When IMAGE originally lost contact, it was using its backup hardware after the primary set shut down. Upon its return, IMAGE is using its primary hardware again.

For those interested in all the details of the saga, NASA has put up a page where it's posting updates on its attempts to revive the satellite. In late January, the Goddard Flight Center was given time on NASA's Deep Space Network to have a listen to the craft. By the end of the month, the agency confirmed that this was indeed IMAGE and started trying to produce a software environment that could process the data it was sending.

"The types of hardware and operating systems used in the IMAGE Mission Operations Center no longer exist," NASA's Miles Hatfield wrote, "and other systems have been updated several versions beyond what they were at the time, requiring significant reverse-engineering."

Patricia Reiff, one of the original team members from 2000, said that there's a lucky break for those tasked with restoring the original operating environment. The software for IMAGE was stored on an old data tape that would be unreadable for any modern hardware. But NASA is a partner (with the ESA) on the Solar and Heliospheric Observatory (SOHO) spacecraft, which has now been in operation for more than 20 years. Thanks to its vintage nature, the SOHO team has a tape drive that can read the four millimeter cassette that holds IMAGE's software.

The data that NASA has read so far suggests that IMAGE's reawakening is even more unexpected than we thought. IMAGE had been built with two sets of redundant hardware (termed A and B), which rescued it back in 2004. Late that year, it suffered a power system reboot; when communication was restored, IMAGE had switched over to the B set of hardware and continued to use that until it dropped communication entirely. Now, IMAGE appears to be back on the A set.

So far, NASA has only checked out the satellite's housekeeping systems. But the agency says that the next step is to attempt to revive the craft's science instruments and determine how many of those are operational. Once it knows what data IMAGE might collect, it'll convene a panel to figure out whether the data can be used to do valuable science on a very small budget.

Reiff, now at Rice University, argues that it certainly could. IMAGE was designed to study the Earth's magnetosphere and the auroras that it creates. The satellite was placed in a highly elliptical orbit, with its closest approach to Earth occurring over the South Pole. That created an extended loop over the North Pole, allowing it to observe the aurorae there for longer and to provide a complete picture of what's going on during its observations.

That complete picture, Reiff argues, has been missing ever since. "What's cool about IMAGE... is that IMAGE can give global context, where all our individual spacecraft are in individual orbits and measure conditions only where they happen to be," she said. Thus, if any local hardware finds something unusual happening, its scientists could potentially turn to the IMAGE data to understand whether the magnetosphere as a whole was doing something unusual at the time.

"I think a really strong case can be made that, if it's healthy and if the instruments are healthy, then IMAGE needs to be reactivated,” Reiff said.

Channel Ars Technica