New Horizons is the first scientific investigation to obtain a close look at Pluto and its moons. The mission will help us understand the icy worlds at the edge of our solar system, three billion miles from Earth, with the first detailed images ever obtained. Scientists hope to find answers to basic questions about the surface properties, geology, interior makeup and atmospheres on these bodies, the first ice dwarf planet and its moons to be visited by a spacecraft. The mission will then visit one or more Kuiper Belt Objects beyond Pluto.
The science objectives are to:
• Map the surface composition of Pluto and Charon
• Characterize the geology and morphology of Pluto and Charon
• Characterize the neutral atmosphere of Pluto and its escape rate
• Search for an atmosphere around Charon
• Map surface temperatures on Pluto and Charon
• Search for rings and additional satellites around Pluto
• Conduct similar investigations of one or more Kuiper Belt Objects
New Horizons launched on January 19, 2006, from Cape Canaveral Air Force Station, Florida, aboard an Atlas V-551 rocket. The fastest spacecraft trip ever to the outer solar system, it reached the orbit of Earth’s Moon in fewer than nine hours.
In February-March 2007 the probe performed a close flyby of Jupiter to get a gravitational boost enroute to Pluto, shortening its cruise time by about three years. The instruments were turned on and returned exciting Jupiter science to Earth, including images of a 200-mile-high plume from the active Tvashtar volcano on the moon Io.
As New Horizons continues on it long interplanetary cruise, the team on Earth conducts annual spacecraft and instrument checkouts, trajectory correction maneuvers, instrument calibrations, and Pluto encounter rehearsals, to make the most of their fast flyby.
The spacecraft will begin collecting data on the Pluto-Charon system about three months and 65 million miles before the closest approach on July 15, 2015. New Horizons will get as close as about 6,000 miles from Pluto and about 17,000 miles from Charon.
Our solar system has three classes of planets: the rocky worlds (Earth, Venus, Mercury and Mars); the gas giants (Jupiter, Saturn, Uranus and Neptune); and the ice dwarfs of the Kuiper Belt which have solid surfaces but a significant portion of their mass is icy material. There are far more ice dwarf planets than rocky and gas giant worlds combined – yet no spacecraft has visited one so far.
A special panel of the National Academy of Sciences was formed in 2001 to advise NASA on a planetary science strategy for the next 10 years. It ranked the exploration of Kuiper Belt Objects, including Pluto, as its highest scientific priority to complete our knowledge of planetary types. As the first mission to investigate this new class of planetary bodies, New Horizons seeks to fill this important gap and round out our knowledge of the planets in our solar system.
It is also an historic mission for the United States, which has been the first nation to reach every planet from Mercury to Neptune with a space probe. The New Horizons mission to Pluto and the Kuiper Belt is the first NASA launch to an ice dwarf planet. It will provide comparisons with dwarf planet Ceres which orbits in the main asteroid belt and will be visited by the Dawn spacecraft in 2015.