[meteorite-list] New Horizons Begins First Stages of Pluto Encounter

[Ron Baalke]

http://pluto.jhuapl.edu/news_center/news/20150115.php

New Horizons Begins First Stages of Pluto Encounter
January 15, 2015

NASA's New Horizons spacecraft has begun its long-awaited, historic encounter 
with Pluto, entering the first of several approach phases that will culminate 
with the first close-up flyby of the Pluto system six months from now.

"NASA's 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 NASA Headquarters, 
Washington. "The New Horizons team worked very hard to prepare for this 
first phase, and they did it flawlessly."

New Horizons launched in January 2006 and, after a voyage of more than 
3 billion miles, will soar close to Pluto, inside the orbits of its five 
known moons, this July 14. The fastest spacecraft ever launched, New Horizons 
awoke from its final hibernation period in early December. Since then, 
the mission's science, engineering and spacecraft operations teams have 
configured the piano-sized probe for distant observations of the Pluto 
system, starting with a long-range photo shoot that begins Jan. 25.

Snapped by New Horizons' telescopic Long-Range Reconnaissance Imager, 
known as LORRI, those pictures will give mission scientists a continually 
improving look at the dynamics of those moons. And they'll 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 craft 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, Colo.

Over the next few months, LORRI will take hundreds of pictures of Pluto 
against star fields to refine the team's estimates of New Horizons' distance 
to Pluto. Though the Pluto system will resemble little more than bright 
dots in the camera's view until May, mission navigators will use those 
data to design course-correction maneuvers that aim the spacecraft toward 
its flyby 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, the New Horizons encounter mission 
manager from the Johns Hopkins University Applied Physics Laboratory in 
Laurel, Md. "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."

Spacecraft operators also track New Horizons using radio signals from 
NASA's Deep Space Network. But 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.

This first approach phase, which lasts until spring, also includes a significant 
degree of other science. New Horizons will take essentially continuous 
data on the interplanetary environment where the Pluto system orbits, 
with its two charged-particle sensors measuring the high-energy particles 
streaming from the Sun, and its dust counter tallying dust-particle concentrations 
in the inner reaches of the Kuiper Belt - the unexplored outer region 
of the solar system that includes Pluto and potentially thousands of similar 
icy, rocky small planets.

More intensive Pluto studies begin in the spring, when the cameras and 
spectrometers aboard New Horizons can provide resolutions better than 
the most powerful telescopes on Earth. Eventually, New Horizons will obtain 
images good enough to map Pluto and its moons better than has ever been 
achieved by any previous first planetary reconnaissance mission. 

APL manages the New Horizons mission for NASA's Science Mission Directorate 
in Washington. Alan Stern, of the Southwest Research Institute (SwRI), 
headquartered in San Antonio, is the principal investigator and leads 
the mission. SwRI leads the science team, payload operations, and encounter 
science planning. New Horizons is part of the New Frontiers Program managed 
by NASA's Marshall Space Flight Center in Huntsville, Alabama. APL designed, 
built and operates the spacecraft.

[Animation]
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 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.
			             	
[Graphic]
Timeline of the approach and departure phases - surrounding close approach 
on July 14, 2015 - of the New Horizons Pluto encounter.