New Horizons mission control in Maryland, US, experienced a loss of communications with the spacecraft beginning at 1654hrs UTC on Saturday, 4 July, and lasting about 80 minutes.
The spacecraft’s autopilot went into ‘safe mode’ and commanded the back-up computer to re-initiate communications with Earth. New Horizons is presently around 4.4 light-hours from Earth, so the spacecraft had undertaken the steps to re-establish communication three hours before the initial break in the signal had even reached Earth.
Mission control are investigating and have promised more information as it becomes available.
Press Release: New Horizons team responds to spacecraft anomaly