Just 10 days before New Horizons closest approach to Pluto it suffered a Safe-Mode event on Saturday causing a lost of communications when the spacecraft handled the event and switched to its backup computer system.
Thankfully the backup system took over and re-established communications and begun sending data back to Mission Control to allow them to determine what caused the Safe-Mode and come up with a plan to resolve it
A New Horizons Anomaly Review Board (ARB) was convened at 4 p.m. EDT on the 4th to gather information on the problem and initiate a recovery plan. The team is now working to return New Horizons to its original flight plan. Due to the 9-hour, round trip communication delay that results from operating a spacecraft almost 3 billion miles (4.9 billion kilometers) from Earth, full recovery is expected to take from one to several days; New Horizons will be temporarily unable to collect science data during that time.
Status updates will be issued as new information is available.