NASA Says Low-Fuel Kepler Has Put Itself Back Into Sleep Mode

NASA's planet hunter Kepler is back offline and the space agency isn't sure why. The change follows the successful downlink of information from the spacecraft, after which point NASA's team ordered the machine into position for its next mission. Upon doing so, the space agency says, scientists discovered the spacecraft had reverted back to a no-fuel-use mode.

We learned back in July that Kepler had only a little bit of fuel left, that prompting NASA to put it into a hibernation mode. That low-power state was intended to preserve the remaining fuel while NASA's team prepared to receive scientific data from the spacecraft's previous mission. NASA had said at the time that any remaining fuel, after the data was acquired, would be put to use for another observational campaign.

Earlier this month, the space agency revealed that Kepler had been put back to sleep due to a pointing issue that prevented the spacecraft from accurately positioning itself. The vessel was left that way until mid-month, the time it was scheduled to use the Deep Space Network for sending data home.

In its most recent update, NASA said that Kepler was successful in transmitting that information and that the team on Earth had received the observational campaign data. However, any intention of sending Kepler off onto a new mission has been put on hold — a no-fuel-use sleep mode has been activated.

Kepler transitioned itself into this state on October 19, a discovery made during a scheduled contact with the spacecraft over the Deep Space Network. NASA doesn't yet have a reason for the change, saying only that its Kepler team is currently investigating the cause of the change and will determine what to do once they know more.