New Horizons Commanded into Last Pre-Pluto Slumber

Artist's concept of the New Horizons spacecraft as it approaches Pluto and its three moons in summer 2015. Image Source: Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute (JHUAPL/SwRI)

Artist’s concept of the New Horizons spacecraft as it approaches Pluto and its three moons in summer 2015. Image Source: Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute (JHUAPL/SwRI)

Laurel, Maryland. August 30, 2014 – NASA’s Pluto-bound spacecraft was put into hibernation yesterday, following a successful 10-week annual checkout period. Mission controllers at the Johns Hopkins University Applied Physics Laboratory verified that New Horizons entered hibernation at 9:21 a.m. EDT. With New Horizons now beyond Neptune’s orbit – more than 2.75 billion miles from Earth – that signal needed just over four hours to reach the mission operations center through NASA’s Deep Space Network.

“This is the final hibernation period on the flight to Pluto,” said Principal Investigator Alan Stern, of the Southwest Research Institute. “When we wake up in December, it’s to prepare for encounter, which begins the following month!”

This summer marked New Horizons’ final annual systems checkout and instrument calibration before Pluto arrival. “The checkout went very well,” said Chris Hersman, New Horizons mission systems engineer from APL. “The spacecraft is healthy and in great shape to begin Pluto encounter activities in early 2015.”

The team also checked the spacecraft’s primary and backup operating systems as well as all seven scientific instruments – and calibrated the instruments to gather “cruise science” data that includes a distant examination of the surfaces of Pluto and its moons early next year. Last month the Long Range Reconnaissance Imager was used for the first optical navigation campaign – snapping images that helped the team home in on Pluto – and the navigation team continued to track the spacecraft to refine its orbit.

A small trajectory correction maneuver on July 15, the mission’s first in four years, corrected the spacecraft’s arrival time at the precisely intended aim point through the Pluto system next July. New Horizons’ traversing of Neptune’s orbit on Aug. 25 officially marked its entry into “Pluto space.”

New Horizons is scheduled to come out of hibernation on December 7, when it will begin two years of Pluto encounter preparations, flyby operations, and data downlinks. Distant-encounter operations at Pluto begin January 4, 2015.

The Johns Hopkins University Applied Physics Laboratory (APL) manages the New Horizons mission for NASA’s Science Mission Directorate; Alan Stern, of the Southwest Research Institute (SwRI) in Boulder, is the principal investigator and leads the mission. SwRI leads the science team, payload operations and encounter science planning; APL designed, built and operates the New Horizons spacecraft. New Horizons is part of the New Frontiers Program managed by NASA’s Marshall Space Flight Center in Huntsville, Alabama.

New Horizons is the first mission in NASA’s New Frontiers program. The spacecraft is expected to pass Pluto at its closest approach next July.