Following the K2 spacecraft’s entering emergency mode on April 9, its operator NASA was able to regain access to it on April 11. Scientists will now breathe easy as the spacecraft had been on the cusp of a new campaign of operations as well as because the emergency mode it was in was rapidly depleting its fuel reserves.
K2 was previously known as Kepler, and since its launch in 2009 had found almost 5,000 exoplanet candidates around the Milky Way. After a malfunction in 2013, the spacecraft’s goals were changed to looking for exoplanets along the plane of our home galaxy while it was rechristened K2. On April 10, a new campaign was slated to begin, to look for exoplanets close to the centre of the Milky Way using a technique called gravitational microlensing (see image on the left).
Following the end of a previous mission on March 23, K2 had been placed in a rest state with its antennae pointed at Earth, to communicate with the ground-based Deep Space Network (look for the callsign ‘KEPL’). The new campaign required the antennae to be pointed toward the Milky Way’s centre so scientists could look at what it was looking at. And that K2 had slipped into emergency mode at all had been discovered during one of many regular checks leading up to the reorientation.
The reasons for why it happened aren’t yet clear – and troubleshooting continues to be hampered by the distance of 120 million km between K2 and Earth. According to a NASA statement, “Earth-based observatories participating in [the campaign] will continue to make observations as Kepler’s health check continues” while, it added, the spacecraft was returned to its lowest fuel-burn mode. “It was the quick response and determination of the engineers throughout the weekend that led to the recovery.”