Operators at the Johns Hopkins University Applied Physics Laboratory in Laurel, Md., confirmed at 9:53 p.m. (EST) that New Horizons, operating on pre-programmed computer commands, had switched from hibernation to “active” mode. Moving at light speed, the radio signal from New Horizons – currently more than 2.9 billion miles from Earth, and just over 162 million miles from Pluto – needed four hours and 26 minutes to reach NASA’s Deep Space Network station in Canberra, Australia.
“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,” said Alan Stern, New Horizons principal investigator from Southwest Research Institute, Boulder, Colo.
The wake-up sequence had been programmed into New Horizons' onboard computer in August, and started aboard the spacecraft at 3 p.m. EST on Dec. 6. About 90 minutes later, New Horizons began transmitting word to Earth on its condition, including the report that it is back in "active" mode.
The New Horizons team will spend the next several weeks checking out the spacecraft, making sure its systems and science instruments are operating properly. They’ll also continue to build and test the computer-command sequences that will guide New Horizons through its flight to and reconnaissance of the Pluto system.
With a seven-instrument science payload that includes advanced imaging infrared and ultraviolet spectrometers, a compact multicolor camera, a high-resolution telescopic camera, two powerful particle spectrometers and a space-dust detector, New Horizons will begin observing the Pluto system on Jan. 15.
New Horizons’ closest approach to Pluto will occur on July 14, but plenty of highlights are expected before then, including, by mid-May, views of the Pluto system better than the Hubble Space Telescope can provide of the dwarf planet and its moons.
Read the article in its entirety at: http://science.nasa.gov/science-news/science-at-nasa/2014/07dec_plutosdoorstep/