New Horizons spacecraft begins first stages of Pluto encounter

NASA’s New Horizons spacecraft begins first stages of Pluto encounter
Artist’s concept of NASA’s New Horizons spacecraft as it passes Pluto and Pluto’s largest moon, Charon, in July 2015. Credit: NASA/JHU APL/SwRI/Steve Gribben

NASA's New Horizons spacecraft recently began its long-awaited, historic encounter with Pluto. The spacecraft is entering the first of several approach phases that culminate July 14 with the first close-up flyby of the dwarf planet, 4.67 billion miles (7.5 billion kilometers) from Earth.

"NASA first mission to distant Pluto will also be humankind's first close up view of this cold, unexplored world in our solar system," said Jim Green, director of NASA's Planetary Science Division at the agency's Headquarters in Washington. "The New Horizons team worked very hard to prepare for this first phase, and they did it flawlessly."

The fastest when it was launched, New Horizons lifted off in January 2006. It awoke from its final hibernation period last month after a voyage of more than 3 billion miles, and will soon pass close to Pluto, inside the orbits of its five known moons. In preparation for the close encounter, the mission's science, engineering and spacecraft operations teams configured the piano-sized probe for distant observations of the Pluto system that start Sunday, Jan. 25 with a long-range photo shoot.

The images captured by New Horizons' telescopic Long-Range Reconnaissance Imager (LORRI) will give mission scientists a continually improving look at the dynamics of Pluto's moons. The images also will play a critical role in navigating the spacecraft as it covers the remaining 135 million miles (220 million kilometers) to Pluto.

"We've completed the longest journey any spacecraft has flown from Earth to reach its primary target, and we are ready to begin exploring," said Alan Stern, New Horizons principal investigator from Southwest Research Institute in Boulder, Colorado.

NASA’s New Horizons is the first mission to Pluto and the Kuiper Belt of icy, rocky mini-worlds on the solar system’s outer frontier. This animation follows the New Horizons spacecraft as it leaves Earth after its January 2006 launch, through a gravity-assist flyby of Jupiter in February 2007, to the encounter with Pluto and its moons in summer 2015. Credit: NASA/JHUAPL

LORRI will take hundreds of pictures of Pluto over the next few months to refine current estimates of the distance between the spacecraft and the dwarf planet. Though the Pluto system will resemble little more than bright dots in the camera's view until May, mission navigators will use the data to design course-correction maneuvers to aim the spacecraft toward its target point this summer. The first such maneuver could occur as early as March.

"We need to refine our knowledge of where Pluto will be when New Horizons flies past it," said Mark Holdridge, New Horizons encounter mission manager at Johns Hopkins University's Applied Physics Laboratory (APL) in Laurel, Maryland. "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."

NASA’s New Horizons spacecraft begins first stages of Pluto encounter
Timeline of the approach and departure phases — surrounding close approach on July 14, 2015 — of the New Horizons Pluto encounter. Credit: NASA/JHU APL/SwRI

The "optical navigation" campaign that begins this month marks the first time pictures from New Horizons will be used to help pinpoint Pluto's location.

Throughout the first approach phase, which runs until spring, New Horizons will conduct a significant amount of additional science. Spacecraft instruments will gather continuous data on the interplanetary environment where the planetary system orbits, including measurements of the high-energy particles streaming from the sun and dust-particle concentrations in the inner reaches of the Kuiper Belt. In addition to Pluto, this area, the unexplored outer region of the solar system, potentially includes thousands of similar icy, rocky small planets.

More intensive studies of Pluto begin in the spring, when the cameras and spectrometers aboard New Horizons will be able to provide image resolutions higher than the most powerful telescopes on Earth. Eventually, the spacecraft will obtain images good enough to map Pluto and its moons more accurately than achieved by previous planetary reconnaissance missions.

Explore further

Last Call: Pluto-bound craft crosses Neptune orbit

More information: For more information about the New Horizons mission, visit
Provided by NASA
Citation: New Horizons spacecraft begins first stages of Pluto encounter (2015, January 16) retrieved 18 August 2019 from
This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.

Feedback to editors

User comments

Jan 16, 2015
from: https://en.wikipe...on_dates

5 May 2015 Better than Hubble Images exceed best Hubble Space Telescope resolution.

Jan 16, 2015
What else is New Horizons planning to do, since it is scheduled to depart Pluto sometime in late July? I would think that an orbital insertion should not have been so difficult to program into the mission. They did some pretty complicated things with Cassini and Huygens, and Cassini is still returning some great data. I think, maybe a look at Planet X? Wishful thinking.

Jan 17, 2015
@baudrunner: It's not just a question of 'programming it in'. We've never orbited a planet we haven't flown by at least once, and given the dearth of information we had about this binary system, attempting an orbital insertion on the first go would be inviting disaster. Add to that the necessity for high velocity launch, the added weight and expense of the extra fuel and braking engine required for what was already a pretty heavy lift, and an orbital mission becomes difficult and risky indeed. Sure, an orbiter would be nice, but remember that the safer fly-by mission gives us the possibility of visiting a second Kuiper object later if a suitable target can be found.

Jan 20, 2015
Add to that the necessity for high velocity launch, the added weight and expense of the extra fuel and braking engine required for what was already a pretty heavy lift..

New Horizons had a launch mass of 478 kilograms vs. Casini-Huygens' dry (minus fuel) mass of 2,523 kilograms. Added weight and expense..? I have to conclude that the Pluto fly-by is a secondary objective, part of the overall mission of exploration beyond the known planetary system.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more