More than a billion miles and almost three years after its remarkable flyby with Pluto in 2015, NASA's New Horizon spacecraft is once again awake and ready to prep for another historic encounter.

The interplanetary probe, which has travelled over 3.8 billion miles from Earth since its launch in early 2006, had been in hibernation mode since Dec. 21 to conserve resources and prevent wear and tear. Earlier this week, NASA officials sent a command for the spacecraft to wake up –– waiting patiently for a response to traverse the more than 3.8 billion miles between it and Earth. Five hours and 40 minutes later at about 2:12 a.m. EDT on June 5, they received a veritable thumbs-up that all systems were healthy and normal.

"We were here in the mission operations center, and it was great," mission operations manager Alice Bowman at the Johns Hopkins Applied Physics Laboratory in Laurel, Maryland, told CBS News. "You know, you always plan for success, so when it goes smoothly that's cause for celebration. It was very nice to have everything run so smoothly. We didn't have to do any reboots, any reconfigurations of the ground systems or anything like that. It went very smooth, and we were very happy."

An artist's conception of 'Ultima Thule,' the next target for NASA's New Horizon's spacecraft. An artist's conception of 'Ultima Thule,' the next target for NASA's New Horizon's spacecraft. (Photo: NASA)

Over the next few months, NASA will prep New Horizons for its New Year's Day flyby with "Ultima Thule," a Kuiper belt object formed during the early years of our solar system.

"Our spacecraft is heading beyond the limits of the known worlds, to what will be this mission's next achievement," Alan Stern, New Horizons' principal investigator, said earlier this year. "Since this will be the farthest exploration of any object in space in history, I like to call our flyby target Ultima for short, symbolizing this ultimate exploration by NASA and our team."

Ultima Thule, classified scientifically as "2014 MU69," is an icy world that, according to observations from the Hubble telescope, is elongated, with two distinct lobes spanning a distance of some 20 miles. Unlike Pluto, which New Horizons captured from a distance of some 7,750 miles above the surface, its current trajectory will have it pass over Ultima from only 2,200 miles. This will allow for image detail with a resolution as fine as 98 feet to 230 feet.

MU69, nicknamed Ultima Thule, is located in the Kuiper Belt; a circumstellar disc brimming with small bodies and objects from the earliest formation of the solar system. MU69, nicknamed Ultima Thule, is located in the Kuiper belt, a circumstellar disc brimming with small bodies and objects from the earliest formation of the solar system. (Photo: NASA)

Because we know so little about Kuiper Belt objects, with direct observations limited to data garnered by telescopes, New Horizons' upcoming rendezvous with Ultima is very much shrouded in speculation. Data captured last year during observation campaigns hint that it may even be two separate objects in orbit around each other, possibly even complemented by a small moon

"That tells us this object is going to have a lot of surprises in store for New Horizons," Marc Buie, the New Horizons science team member who led 2017's observation campaign, said in a statement. "We're going to see something that dates back to the formation of the solar system."

After screaming by Ultima Thule at a cruising speed of over 31,000 mph, New Horizons will set its sights on more than two-dozen other Kuiper belt objects. Jim Green, director of NASA's Planetary Science Division at Headquarters in Washington, D.C., hopes this new stage of exploration continues to capture the world's attention.

"New Horizons is on the hunt to understand these objects, and we invite everyone to ring in the next year with the excitement of exploring the unknown," he said.

Michael d'Estries ( @michaeldestries ) covers science, technology, art, and the beautiful, unusual corners of our incredible world.

NASA's New Horizon wakes up, prepares for New Year's Day flyby of 'Ultima Thule'
After a six-month hibernation, the deep space probe New Horizon is awake and healthy ahead of its rendezvous with a trans-Neptunian object from the Kuiper belt.