GoKawiilIt takes a long time to reach anything at the edge of our solar system, and sometimes even spacecraft need to take a nap on a long journey. NASA's New Horizons did just that, and the agency says the spacecraft woke itself up on schedule after a 321-day sleep, the longest nap it's ever taken.
Flight controllers at Johns Hopkins Applied Physics Laboratory put the spacecraft to sleep on Aug. 7, 2025, with the world's longest sleep timer. New Horizons woke itself up using its onboard commands on June 23. NASA reports that the spacecraft survived its long sleep without any issues and is "healthy."
"Every status report through this hibernation period was 'green,' meaning all was well aboard New Horizons each and every week," said Alice Bowman, New Horizons mission operations manager at APL, in a statement on Tuesday.
Exploring Pluto and Arrokoth was New Horizons' primary mission, but NASA has extended the mission to go for as long as New Horizons can keep waking itself up from its long, frequent naps.
APL operators will download and analyze the spacecraft's health and safety data, just to be sure. Following that is the science data that was collected by the three onboard science instruments while the spacecraft was asleep.
Johns Hopkins APL flight controllers Mark Lahr and Josh Albers, and mission operations manager Alice Bowman, started monitoring New Horizons' telemetry data immediately after the spacecraft woke up NASA/Johns Hopkins APL/Justin Gladden
One of many naps
This isn't a new exercise for New Horizons. The spacecraft originally launched in 2006 and currently sits in the Kuiper Belt, a doughnut-shaped belt around the outer solar system that houses Pluto and other icy bodies. While it is frequently compared to the asteroid belt that separates Mars from Jupiter, the Kuiper Belt is much larger and contains mostly ice instead of rocks.
New Horizons has called the belt home since 2015, when it became the first spacecraft to study Pluto up close. You can bet your bottom dollar that it was in hibernation mode leading up to the event and was put back to sleep while it traveled to its next object of study, Arrokoth, in January 2019.
"Since 2007, New Horizons has hibernated 23 times, for periods ranging from just days to many months," NASA said. "Hibernation is a way to extend spacecraft life and reduce mission operation costs. During hibernation, New Horizons remains in a stable spinning mode with much of the spacecraft unpowered."