NASA has woken up its New Horizons probe, which will experience a close encounter with Pluto and its moons in 2015.

According to Space.com, New Horizons' 2.9 billion mile journey started with a Jan. 2006 launch and the spacecraft spent a majority of that time in a hibernation idle state. New Horizons will study Pluto, its moon Charon and several other smaller ones in the Kuiper Belt.

"This is a watershed event that signals the end of New Horizons crossing of a vast ocean of space to the very frontier of our solar system, and the beginning of the mission's primary objective: the exploration of Pluto and its many moons in 2015," Alan Stern, New Horizons principal investigator from the Southwest Research Institute in Boulder, Colo., said in a press release.

Like the Rosetta spacecraft that took the Philae lander to mount a comet, New Horizons had to travel most of the way in hibernation mode to conserve energy. NASA woke New Horizons at six- to 10-month intervals to make sure it was still in working order.

"Technically, this was routine, since the wake-up was a procedure that we'd done many times before," Glen Fountain, New Horizons project manager, said in the release. "Symbolically, however, this is a big deal. It means the start of our pre-encounter operations."

The New Horizons team will spend the next several weeks ensuring the probe's various instruments are warming up properly. New Horizon will make its closest encounter with Pluto, the furthest planet from the sun in our solar system, in July 2015.

"New Horizons is on a journey to a new class of planets we've never seen, in a place we've never been before," Hal Weaver, a New Horizons project scientist, said in the release. "For decades we thought Pluto was this odd little body on the planetary outskirts; now we know it's really a gateway to an entire region of new worlds in the Kuiper Belt, and New Horizons is going to provide the first close-up look at them."