The mission was launched Jan. 19, 2006. The New Horizons team says it considers the spacecraft's flight to Pluto to contain three three-year segments -- early cruise, mid-cruise and late cruise.
"We are now turning the corner from mid-cruise to late cruise," principal investigator Alan Stern of the Southwest Research Institute in Boulder, Colo., told SPACE.com. "We're really in the final stages."
The late cruise stage will see mission scientists and engineers checking out the spacecraft's systems and preparing for the January 2015 flyby of Pluto and its four known moons, NASA said.
During the flyby, New Horizons will study Pluto and its moons with seven different instruments, giving scientists their first good look at any dwarf planet -- a class of celestial body suspected to be far more numerous in the solar system than terrestrial and giant planets combined.