NASA's New Horizons spacecraft awakens from hibernation for science beyond Pluto

NASA's New Horizons spacecraft has emerged from a yearlong hibernation, ready to conduct unprecedented science beyond Pluto. The probe, which famously flew past Pluto in 2015, is now on course for a flyby of a small Kuiper Belt object known as 2014 MU69, which it will reach on Jan. 1, 2019. This will be the most distant flyby in the history of space exploration.

The spacecraft's awakening affects scientists and space enthusiasts worldwide, as it marks the beginning of a new phase of discovery in the outer solar system. The data New Horizons gathers from 2014 MU69 could provide insights into the early formation of the solar system, as Kuiper Belt objects are considered pristine remnants from that era. The mission matters because it offers a unique opportunity to study a primitive world that has remained largely unchanged for billions of years.

New Horizons was put into hibernation on April 7, 2017, to conserve power and reduce wear on its systems. It was awakened on June 4, 2018, at 12:33 a.m. EDT, when a pre-programmed alarm clock triggered the spacecraft to power up its systems and send a signal back to Earth. The signal, which took about 5 hours and 43 minutes to travel the 3.7 billion miles to Earth, was received by the Johns Hopkins Applied Physics Laboratory in Maryland.

Background: New Horizons launched in 2006 and conducted the first-ever flyby of Pluto in July 2015, revealing a complex world with mountains, glaciers, and a heart-shaped plain. After that, the spacecraft was redirected toward 2014 MU69, which was discovered by the Hubble Space Telescope in 2014. The object is about 20 miles (30 kilometers) across and is thought to be a contact binary, meaning two smaller bodies that have gently merged.

Next steps: The New Horizons team will now begin a series of observations and trajectory adjustments to prepare for the flyby. The spacecraft will take images of 2014 MU69 to refine its orbit and shape, and will also search for potential hazards such as rings or debris. The flyby itself will occur at a distance of about 2,200 miles (3,500 kilometers) from the object, with the spacecraft traveling at a speed of about 32,000 mph (51,500 km/h). Data from the encounter will be transmitted back to Earth over the following months.