After the longest hibernation period in its history, lasting almost a year, NASA’s New Horizons spacecraft has emerged in good condition and is ready to begin transmitting scientific data collected in the distant Kuiper Belt, far beyond Pluto.
Features of the Hibernation Mode
On June 23, flight controllers at the Johns Hopkins Applied Physics Laboratory (APL) in Laurel, Maryland, confirmed that the New Horizons spacecraft, acting according to commands stored in its memory and sent to its main computer last July, had successfully emerged from a 321-day hibernation mode that began on August 7. Since the spacecraft is now located approximately 5.9 billion miles, or 9.5 billion kilometers, from Earth, the radio signals carrying this confirmation reached the APL Mission Operations Center through NASA’s Deep Space Network station near Madrid, Spain, after about 8 hours and 52 minutes. This was reported by phys.org.
The mission team usually places New Horizons into energy-saving hibernation during long periods of flight. While the spacecraft is in hibernation, operators do not send commands or receive data, but the spacecraft continues to collect and store data around the clock from its heliospheric plasma sensors, the Solar Wind Around Pluto instrument, the Pluto Energetic Particle Spectrometer Science Investigation, and its cosmic dust detector, the Venetia Burney Student Dust Counter.
Scientific Instruments Aboard New Horizons
Alice Bowman, mission operations manager for New Horizons at APL, noted that the spacecraft had been sending a weekly status signal to Earth through the Deep Space Network.
According to Bowman, now that New Horizons has resumed active operations, the team will begin downlinking spacecraft health and safety data, followed by data from three scientific instruments. In about three weeks, the onboard ultraviolet spectrograph Alice will study the distribution of hydrogen gas in the outer heliosphere, while the Solar Wind Around Pluto instrument, the Pluto Energetic Particle Spectrometer Science Investigation, and the Venetia Burney Student Dust Counter will continue their measurements. At the same time, the ground team will carry out a series of checks of the spacecraft and its instruments.
The team is also completing an update to the ground-system software that will make spacecraft operations easier to support. Testing is already underway and is expected to continue throughout the year.
The Uniqueness of the Mission
New Horizons is operating on updated autonomous-control logic designed for work at greater distances from the Sun, taking into account the expected decline in available power and the naturally increasing radio-signal travel time.
NASA’s exploration of this remote region of the Solar System is another stage in a journey that began in January 2006 with the fastest launch in history; continued with a flyby of Jupiter in February 2007, during which the spacecraft captured striking images of the gas giant and its moons; included the first exploration of the Pluto system in July 2015; the first study of a Kuiper Belt object, Arrokoth, in January 2019; and has since continued with unique studies of the Sun’s outer heliosphere and dozens of Kuiper Belt objects.
