There's nothing more disorienting than falling asleep in transit only to wake up and find you've somehow drifted billions of miles beyond the orbit of Pluto.

Fortunately for NASA's New Horizon spacecraft, which scientists just awakened from a nearly yearlong hibernation at the solar system's edge, all systems are in "good health," according to a NASA statement. Now, with the probe recovered from its 321-day sleep and beginning to transmit science data again, New Horizons appears ready to continue its mission of studying the mysterious boundary where the sun's realm ends and interstellar space begins.

"Every status report through this hibernation period was 'green,' meaning all was well aboard New Horizons each and every week," Alice Bowman, the New Horizons mission operations manager at the Johns Hopkins Applied Physics Laboratory in Maryland, said in the statement.

New Horizons launched in 2006, breaking the record for fastest-ever space launch at roughly 36,400 mph (58,500 km/h). On its way to the edge of the solar system, the spacecraft picked up speed during a flyby of Jupiter in 2007 and then again while passing Pluto in 2015. Today, New Horizons is about 5.9 billion miles (9.5 billion kilometers) from Earth, or roughly 64 times the distance from Earth to the sun (64 astronomical units, or AU).

With the exception of the twin Voyager probes that launched in 1977, New Horizons is the farthest working spacecraft in the universe. (Two other probes, Pioneer 10 and 11, have traveled farther, but each stopped working several decades ago.)

Like the Voyager twins, New Horizons is on a trajectory toward the heliopause — the extreme outer edge of the sun's influence, where solar wind collides with the interstellar medium.

The Voyager probes proved that this dividing line is a measurable, physical boundary in space, marked by a hot, thick plasma barrier. However, New Horizons will eventually pass this boundary with far more sensitive instruments than the Voyagers held, enabling it to collect the most detailed data about this region ever.