NASA’s exoplanet hunting satellite is back and up running

NASA’s Transiting Exoplanet Survey Satellite (TESS), a space-based exoplanet hunter, has resumed operations following a technical issue that caused it to be put into safe mode earlier this week. The issue began on Wednesday, October 12, when a problem with the satellite’s computer arose. “The spacecraft is in a stable configuration that suspends science observations. Preliminary investigation revealed that the TESS flight computer experienced a reset,” NASA wrote in an update at the time. “The TESS operations team reported that science data not yet sent to the ground appears to be safely stored on the satellite.

Recovery procedures and investigations are underway to resume normal operations, which could take several days.”

Artist's illustration of NASA's Transiting Exoplanet Survey Satellite. Artist’s illustration of NASA’s Transiting Exoplanet Survey Satellite. NASA

Fortunately, the problem was quickly resolved. The NASA team overseeing TESS powered it back up and the spacecraft was able to orient itself correctly. The data it collected recently appears to be intact and will be downloaded soon, and the satellite should be able to resume its operations.

However, the team does not yet know the underlying cause of the computer reset. NASA says that the team will continue investigating to try to identify what caused the problem. TESS launched in 2018 and is orbiting around the Earth in a highly elliptical orbit which allows it to see the sky of both the northern and southern hemispheres.

It uses the transit method to detect exoplanets. Because exoplanets are relatively small and very distant, they generally cannot be directly imaged. Instead, their presence is inferred by their effects on their host stars.

A transit occurs when a planet passes in front of its star, which reduces that star’s apparent brightness for a short time. By detecting these transit events, TESS can identify new exoplanets. TESS has discovered over 5,000 exoplanet candidates in its mission so far, lasting just over four years.

Many of these are considered candidates rather than confirmed planets because multiple observations are required to confirm a potential planet’s status.

Some of the planets or planetary candidates which TESS has discovered include a planet where a year lasts only eight hours, several potentially habitable worlds, and a strange planet that should have been engulfed by its star.