After traveling nearly five billion kilometers over nine years, NASA’s New Horizons spacecraft has just entered the first phase of approach in its upcoming epic encounter with Pluto. The series of several planned approaches will culminate on July 14 with the first ever close-up flyby of Pluto—a dwarf planet 7.5 billion kilometers (4.67 billion miles) from Earth.
New Horizons, launched into space on January 19, 2006, is the first mission to the former ninth planet. The spacecraft woke up from its final hibernation period just last month to English tenor Russell Watson’s "Where My Heart Will Take Me.” Since 2007, the piano-sized probe has spent 1,873 days (or two-thirds of its flight time) largely unpowered over the course of 18 separate hibernation periods to reduce wear and tear.
“We’ve completed the longest journey any spacecraft has flown from Earth to reach its primary target, and we are ready to begin exploring,” New Horizons principal investigator Alan Stern from Southwest Research Institute says in a news release.
The plan is to head into the orbit of one of Pluto’s five known moons. And in preparation for this summer’s close encounter, scientists have been configuring the probe for distant observations of Pluto, including a long-range photo shoot beginning January 25 and continuing through the next few months. Images taken by the on-board Long-Range Reconnaissance Imager will help navigate the probe across the last 220 million kilometers (135 million miles).
“We need to refine our knowledge of where Pluto will be when New Horizons flies past it,” says Mark Holdridge of Johns Hopkins University’s Applied Physics Laboratory. “The flyby timing also has to be exact, because the computer commands that will orient the spacecraft and point the science instruments are based on precisely knowing the time we pass Pluto—which these images will help us determine.”
This first approach phase will run until the spring, and various instruments on New Horizons will be gathering interplanetary data continuously, including measurements of high-energy particles streaming from the sun and the concentrations of dust particles in the Kuiper Belt, an unexplored area in the outer region of our solar system that could contain thousands of small icy, rocky planets.
Then in the springtime, cameras and spectrometers aboard the spacecraft will begin capturing high-resolution images that’ll help map Pluto and its moons more accurately than ever before. "We really are on Pluto's doorstep," Stern says.