NASA’s New Horizons spacecraft has woke up today after six months of electronic hibernation.

Flying through the Kuiper Belt more than 3.7 billion miles (6 billion kilometers) from Earth, New Horizons phoned home to let NASA flight controllers know it’s in good health.

“We were here in the mission operations center, and it was great,” said Mission operations manager Alice Bowman at the Johns Hopkins Applied Physics Laboratory in Laurel, Maryland. “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.”

New Horizons is speeding toward a flyby of Ultima Thule—about a billion miles (1.6 billion kilometers) beyond Pluto – on Jan. 1, 2019.

Ultima Thule is a billion miles beyond Pluto and 3.8 billion miles from Earth. It’s thought to be an icy object smaller than Pluto, and preliminary long-range observations suggest it could consist of multiple objects.

“The primary flyby distance is 3,500 kilometers (2,100 miles),” Bowman said.

New Horizons flew past Pluto at a distance of about 7,800 miles. Passing within a scant 2,100 miles of Ultima Thule, the spacecraft’s main camera should be able to resolve surface features as small as a basketball despite the dim lighting and the spacecraft’s high speed.

Over the next two months, New Horizons will keep its main antenna pointed toward Earth to maintain uninterrupted communications.

“We can’t take any pictures in that state, but it allows us to load software, burn flash, update ephemerides (navigation files), do comm checks with our instruments, basically do all the housekeeping to get ready for the encounter,” she said.

In August, the team will command New Horizons to begin making distant observations of Ultima, images that will help the team refine the spacecraft’s course to fly by the object.

New Horizons made a historic flight past Pluto and its moons on July 14, 2015, returning data that has transformed our view of these intriguing worlds near the inner edge of the Kuiper Belt. The spacecraft is scheduled to stay active until late 2020, in order to transmit all the data from the Ultima Thule flyby and make further science observations.

New Horizons current position can be tracked online here.