NASA Loses Contact With New Horizons; Pluto Spacecraft Enters 'Safe Mode'

Update: NASA has regained communications with New Horizons. Full story here.

Ten days before NASA ’s New Horizons spacecraft was due to make its closest approach to Pluto, the space agency reports that at 1:54 PM EDT on the afternoon of July 4th local U.S. time, it lost contact with the $700 million unmanned flyby mission for more than an hour and twenty minutes. Controllers were able to regain a signal from the probe via NASA’s Deep Space Network at 3:15 PM EDT, but as a result, the spacecraft’s systems have entered safe mode until mission engineers can diagnose the problem.

During the time that it was out of contact with Earth, the probe’s “autonomous autopilot on board the spacecraft recognized a problem and – as it’s programmed to do in such a situation - switched from the main to the backup computer,” NASA reports in a statement issued via Johns Hopkins University’s Applied Physics Lab, which manages the mission for the space agency. NASA says “the autopilot placed the spacecraft in “safe mode,” and commanded the backup computer to reinitiate communication with Earth.”

The spacecraft, NASA reports, then began transmitting telemetry to help the engineers determine the root of the problem.

“A New Horizons Anomaly Review Board ( ARB ) was convened at 4 PM EDT to gather information on the problem and initiate a recovery plan,” the space agency noted. That team is now working to return the mission to its original flight plan which the agency reports may take from up to several days, during which the mission will not be able to collect any science data. '

Recovery from the event is inherently hamstrung due to the 9-hour, round trip communication delay that the agency says “results from operating a spacecraft almost 3 billion miles (4.9 billion kilometers) from Earth.”

As yet, there is no word on whether this will ultimately interfere with the spacecraft’s planned July 14 rendezvous with Pluto. But nearly a decade after launch, the mission has already been sending science data back from this unexplored outermost region of our Solar System. Just last week, members of the probe’s science team announced the detection of frozen methane on the dwarf planet’s surface.

The original flight plan was for New Horizons to make a first-ever flyby of the frozen world at 7:49:58 EDT on July 14. Hours after its flyby, planetary scientists were hoping to observe sunlight as it passes through Pluto’s atmosphere in order to get a better handle on the tiny world’s atmospheric composition. From there, the plan was to continue on to science targets of opportunity in our Solar System’s Kuiper Belt, a wild, largely uncharted nether region of comets, ice dwarfs and planetary debris.

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