Mission Elapsed Time:
Beginning 1/19/06 19:00:00 UTC
2,549 Days (6.98 yrs.) 09 Hours 28 Minutes
Pluto Closest Approach Operations Begin:
4/12/15 00:00:00 UTC
819 Days (2.24 yrs.) 19 Hours 39 Minutes
Pluto Closest Approach
7/14/15 11:49:59 UTC
913 Days (2.50 yrs.) 07 Hours 28 Minutes
New Horizons Gets a New Year’s Workout
Like many of us, New Horizons is starting the new year with a workout regimen. After six months of cruising quietly through the outer solar system, NASA’s Pluto-bound spacecraft came out of hibernation last weekend for three weeks of activity that include system checks, a new flight software upload and science data downloads.
Map of Outer Solar System (with Kuiper Belt Objects)
The mission operations team at the Johns Hopkins University Applied Physics Laboratory (APL) in Maryland “woke” New Horizons from electronic slumber on Jan. 6. First tasks included evaluating real-time spacecraft data (which indicated New Horizons was in good health), sending operating commands to the spacecraft’s main computer, and gathering tracking data that will help the navigation team keep New Horizons on course toward the Pluto system. Operators are communicating with New Horizons through NASA’s largest Deep Space Network antennas in Spain, Australia and the U.S. (California).
NASA DSN in Madrid, Spain
Starting today, through Jan. 12, the team will upload new software for the Command and Data Handling (C&DH) system, an upgrade that addresses a cause of resets in the spacecraft’s computer. If you can’t wait mere minutes to download a new app, this will make you cringe: With radio signals needing nearly 3 hours and 40 minutes to reach the spacecraft – which is about 2.4 billion miles (3.9 billion kilometers) from Earth, between the orbits of Uranus and Neptune – the full software upload will take about 44 continuous hours, says New Horizons Mission Operations Manager Alice Bowman, of APL. “The Mission Operations Center must remain in constant contact with New Horizons in case the unexpected happens, despite the numerous preparations and precautions the team has taken,” Bowman says.
C&DH: The Brains ‘Inside’ New Horizons
The command and data handling system – a radiation-hardened 12-megahertz Mongoose V processor guided by intricate flight software – is the spacecraft’s “brain.” Radiation hardening is the act of making electronic components and systems resistant to damage or malfunctions caused by ionizing radiation (particle radiation and high-energy electromagnetic radiation), such as those encountered in outer space.
Radiation Hardened 12 Megahertz Mongoose V Processor
The processor distributes operating commands to each subsystem, collects and processes instrument data, and sequences information sent back to Earth. It also runs the advanced “autonomy” algorithms that allow the spacecraft to check the status of each system and, if necessary, correct any problems, switch to backup systems or contact operators on Earth for help. “I think of the C&DH system software update as a ‘tune-up’ at the 2.4 billion-mile marker,” says APL’s Glen Fountain, New Horizons project manager.
PEPSSI & SWAP
Downloads this month include interplanetary plasma data gathered by the Pluto Energetic Particle Spectrometer Science Investigation (PEPSSI) and Solar Wind Around Pluto (SWAP) instruments, shown above during prelaunch testing. (PEPSSI is at the top.) Other activities planned over the next 20 days include radio frequency system and Radio Science Experiment checkouts, and a download of cruise science data from New Horizons’ space plasma instruments – SWAP and PEPSSI – which have been studying the charged-particle populations of the outer solar system. Additionally, New Horizons’ solid-state digital recorders (filled with data from last summer’s near-Pluto encounter rehearsal) will be erased in preparation for this summer’s rehearsal of the nine days surrounding Pluto close approach.
New Horizons Current Course and Position in Three Dimensions:
The spacecraft will be put back into hibernation on Jan 3. New Horizons has spent about 80 percent of the past five years in hibernation, a low-power mode that reduces operation costs, frees up Deep Space Network tracking resources for other missions and lessens wear and tear on spacecraft electronics. During the past two years, this hibernation mode has been enhanced to enable New Horizons to collect plasma science data in interplanetary space. The team wakes New Horizons two or three times a year to check systems and run tests, but after May 2014 the spacecraft will remain “on” without hibernating through the 2015 Pluto encounter.