New Horizons awakens from final hibernation
From a distance of 2.9 billion miles across the vastness of the solar system, NASA’s New Horizons spacecraft confirmed Dec. 6 that it successfully awakened from its 19th and final hibernation. At 9:28 p.m. EST (0230 GMT), after waiting nearly four and a half hours for the signal to travel to Earth, mission controllers at the Johns Hopkins University Applied Physics Lab (JHUAPL) in Laurel, MD announced they received confirmation that New Horizons had successfully come out of hibernation for the final time.
The Planetary Society celebrated New Horizons’ emergence from hibernation with a live YouTube broadcast on Saturday night Dec. 6 at 9 PM EDT with host Matt Kaplan, mission Co-Investigator Bonnie Buratti, and Deep Space Network New Horizons liaison Felicia Sanders. Announcement of the signal confirming the wakeup was made toward the end of the program.
Video courtesy of The Planetary Society
Saturday night marked the 19th and final time New Horizons has emerged from the hibernation state it has pioneered, and from a technical standpoint, the wake up is routine. During its nearly nine-year journey since launch on Jan. 19, 2006, it has spent 1,873 days, or one third of the journey, in hibernation.
Hibernation has preserved the instruments onboard over the long trip and lessened risks of system failures. During hibernation periods, which lasted from 36 to 202 days, most of the instruments onboard the spacecraft were powered down. The spacecraft still communicated weekly with mission control, with the onboard flight computer confirming all was in order. The computer monitored the status of all instruments onboard regularly.
Each time New Horizons was awakened, the mission team checked out its systems, performed course corrections, calibrated the seven instruments onboard, and conducted rehearsals for the actual flyby. From a symbolic perspective, the last awakening of the spacecraft is anything but routine.
We have data! She’s awake!
— NewHorizons2015 (@NewHorizons2015) 7 Décembre 2014
Traveling at the universal speed of light, the signal from the piano-sized spacecraft, now only 162 million miles (less than twice the Earth’s distance from the Sun) from Pluto, its exploration target, took four hours and 26 minutes to arrive at NASA’s Deep Space Network (DSN) in Canberra, Australia.
Principal Investigator Dr. Alan Stern of the Southwest Research Institute in Boulder, CO, emphasized the significance of the first mission to explore the solar system’s third planetary zone.
“This is a watershed event that signals the end of New Horizons crossing of a vast ocean of space to the very frontier of our solar system, and the beginning of the mission’s primary objective: the exploration of Pluto and its many moons in 2015,” he said.
Glen Fountain, New Horizons project manager at JHUAPL, noted the emergence from final hibernation marks the beginning of New Horizons’ pre-encounter operations. These operations, which will be carried out over the next few weeks, involve a complete review of the spacecraft and all its instruments to make sure they are functioning at optimal level. Computer command sequences for the flyby will be created, tested, and uploaded during this period.
The actual mission, observation of Pluto and its five moons, will begin on January 15. The first images of Pluto surpassing those taken by the Hubble Space Telescope will taken in late April or early May. Approach Phase 1 (AP1) technically starts on Jan. 6 and lasts until April 4. During this phase, the spacecraft’s Long Range Reconnaissance Imager (LORRI), a telescopic camera designed for long range observation, will begin imaging Pluto and its moons.
Two other instruments, the Solar Wind at Pluto (SWAP), and the Pluto Energetic Particle Spectrometer Science Investigation (PEPPSI), will measure plasma. A solar wind and plasma spectrometer, SWAP is designed to measure the escape rate of Pluto’s atmosphere and the planet’s interaction with the solar wind. PEPPSI is an energetic particle spectrometer. It will measure both the density and composition of plasma ions escaping from Pluto’s atmosphere.
During Approach Phase 2 (AP2), from April 4-June 23, LORRI will start to obtain images with better resolution than those of Hubble. Priority will be given to searching for rings and additional moons as well as to taking color images. The best global maps of both Pluto and its largest satellite, Charon, will be taken during Approach Phase 3 (AP3), from June 23-July 13.
The Linear Etalon Imaging Spectral Array (LEISA), an infrared imaging spectrometer and sub-instrument of Ralph, which Stern describes as the “mission’s main sense of sight,” will study Pluto’s atmosphere in the infrared.
Alice, Ralph’s other sub-instrument, the ultra-violet spectrometer, will concurrently study Pluto’s atmosphere in the ultra-violet. Both will search the Plutonian atmosphere for winds, clouds, and hazes. Meanwhile, SWAP and PEPPSI will look for ions and bow shock.
The height of the mission is the Near Encounter Phase, July 13-15, time of the highest priority observations and closest approach to the Pluto system. Closest approach will occur on July 14 at 7:49:59 AM EST (12:49:59 GMT), when New Horizons will pass within 6,200 miles of the planet’s surface, traveling at a speed of 27,000 miles per hour.
As a precautionary measure, all science data collected to date will be downlinked on July 12-13. This data, which will include the best color images of Pluto and Charon, will be returned to assure the mission’s key findings are preserved in the unlikely event the spacecraft is destroyed by an impact as it flies through the Pluto system.
Three departure phases will then follow. During Departure Phase 1 (DP1), from July 15-August 4, SWAP and PEPPSI will study Pluto’s magnetotail and detailed observation of small moons Nix and Hydra will be conducted. The Radio Science Experiment (REX) instrument will measure the atmospheres and temperatures of Pluto and Charon.
During Departure Phase 2 (DP2), from Aug. 4-Oct. 22, the Venetia Burney Student Dust Counter (SDC) will measure interplanetary dust. Efforts to measure the escape rate of Pluto’s atmosphere will continue, as will the search for rings and moons.
Departure Phase 3 (DP3), which runs from October 22-January 1, 2016, will involve continued measurements of interplanetary dust and atmospheric escape rate.
New Horizons will image Pluto’s night side during the departure phases, using Ralph to look back at both Pluto and Charon. The spacecraft will send back data on the Pluto system through the end of 2016. Compressed images will be returned within days at each phase while uncompressed images will be sent back over a period of months.
Late next year, one of three target Kuiper Belt Objects (KBOs) will be chosen for the second part of the mission, a KBO flyby. Once the selection is made, a trajectory will be set, and the spacecraft will be directed to its target, which it will reach in late 2018 or early 2019. Additional funding will be required for the KBO flyby. Mission team members plan to write a funding proposal in 2016.
Upon awakening, New Horizons was serenaded by singer Russell Watson, who made a special recording of “Where My Heart Will Take Me” to celebrate the occasion. Star Trek fans will recognize the song, as it’s the theme song of the Star Trek Enterprise. Watson has performed it for NASA astronauts for various missions, but this is the first time it has been used for a spacecraft mission.
Laurel Kornfeld is an amateur astronomer and freelance writer from Highland Park, NJ, who enjoys writing about astronomy and planetary science. She studied journalism at Douglass College, Rutgers University, and earned a Graduate Certificate of Science from Swinburne University’s Astronomy Online program. Her writings have been published online in The Atlantic, Astronomy magazine’s guest blog section, the UK Space Conference, the 2009 IAU General Assembly newspaper, The Space Reporter, and newsletters of various astronomy clubs. She is a member of the Cranford, NJ-based Amateur Astronomers, Inc. Especially interested in the outer solar system, Laurel gave a brief presentation at the 2008 Great Planet Debate held at the Johns Hopkins University Applied Physics Lab in Laurel, MD.