New Horizons (PKB):
NASA's New Horizons spacecraft will make the first ever close-up study of Pluto, its moons, and the worlds within the
Kuiper Belt at the edge of our solar system.
When it encounters Pluto in July 2015, the robotic (unmanned) spacecraft will use its seven onboard scientific instruments to study the atmospheres, surfaces, interiors, and the intriguing environments of the space around Pluto and its three moons (Charon, Nix, and Hydra). New Horizons will also map Pluto's
far-side, and look for evidence of rings and magnetic fields around Pluto and Charon. The spacecraft will then venture on to study more objects within the Kuiper Belt.
Despite its demotion from
planet status in 2006, Pluto has largely been a mystery since its 1930 discovery by Lowell Observatory astronomer Clyde Tombaugh. The New Horizons spacecraft will search for answers to some basic questions about the ice dwarf and its companions-- What does the surface of Pluto look like? What geologic formations exist? What is the atmosphere made of and how does it behave? How do particles ejected from the sun, called the "solar wind," interact with Pluto's atmosphere?
The 465 Kilogram (1025 pound) New Horizons spacecraft was launched via an Atlas V 551 rocket on January 19, 2006, from Cape Canaveral Air Force Station in Florida. A Centaur second stage and STAR 48B solid rocket third stage pushed New Horizons towards its first rendezvous.
On February 28, 2007, just 13 months after launch, the New Horizons spacecraft passed our solar system's largest planet Jupiter, picking up new scientific data, as well as a powerful slingshot-like gravity assist that trimmed three years off the spacecraft's journey to Pluto and beyond. During the Jupiter flyby, New Horizons observed lightning near the gas giant's poles, the creation of fresh ammonia clouds, and boulder-size clumps speeding through Jupiter's faint rings. The spacecraft also collected data on volcanic eruptions on Jupiter's moon Io, and the path of charged particles moving back and forth across the -- previously unexplored -- length of Jupiter's long magnetic tail.
During the Jupiter flyby, New Horizons was able to observe the icy moon Europa. The information collected by the spacecraft supports the theory that Europa has an ocean of liquid water underneath its icy crust. Images from the flyby show odd concentric circles on the icy crust, evidence of wandering poles. New Horizons also completed the mapping of a long trench, first seen by the Voyager spacecraft in 1979.
The spacecraft will "sleep" while slowly spinning during most of its eight-year interplanetary trek from Jupiter to Pluto. Mission controllers at home on Earth will "wake up" New Horizons for 50 days each year to perform necessary "checkups" on its instruments.
In 2014, the spacecraft will "wake up" in order to prepare for its 2015 encounter with Pluto and its moons. At this time, mission controllers will check instruments and send New Horizons instructions for the flyby.
In July 2015, New Horizons will encounter Pluto and its three moons -- Charon, Nix, and Hydra. During its 150-day flyby, the New Horizons spacecraft will be moving at a speed of 14 kilometers per second (31,300 miles per hour). At closest approach, the spacecraft will be within 9650 kilometers (about 6000 miles) of the center of Pluto's mass.
In the final phase of its mission, New Horizons will head deeper into the Kuiper Belt in search of icy comets and objects that may be the original source of water in our solar system. The largest structure in our planetary system, the Kuiper Belt is believed to be the source of short-term comets (those with orbits of 200 years or less), and may be home to more than 100,000 miniature worlds larger than 100 kilometer.
New Horizons carries seven scientific instruments to study the surfaces of Pluto, its moons, and any Kuiper Belt objects that New Horizons encounters. The spacecraft's most prominent design feature is a nearly 7-foot (2.1-meter) dish antenna, through which it will communicate with Earth from as far as 4.7 billion miles (7.5 billion kilometers) away. New Horizons includes a visible and infrared imager/spectrometer (RALPH), an ultraviolet imaging spectrometer (ALICE), a radio science experiment for studying atmospheres (REX), a telescopic camera (LORRI), a solar wind and plasma spectrometer (SWAP), an energetic particle spectrometer (PEPSSI), and a space dust counter (SDC).
The "eyes" of the mission, the visible and infrared imager/spectrometer (RALPH) is a suite of instruments that will show what Pluto, its moons, and other Kuiper Belt objects truly look like. With light levels 1,000 times fainter than Earth daylight, and using half the wattage of a nightlight, RALPH will study surface geology and composition, and make surface temperature maps. Inside of RALPH's Multispectral Visible Imaging Camera (MVIC) are three black-and-white, and four color imagers. The instrument also contains an infrared compositional mapping spectrometer called the Linear Etalon Imaging Spectral Array (LEISA). RALPH was developed by Ball Aerospace Corporation, NASA Goddard Space Flight Center, and the Southwest Research Institute.
The ultraviolet imaging spectrometer (ALICE) will study the structure and makeup of Pluto's atmosphere. The combination compact telescope, spectrograph, and sensitive electronic detector, ALICE will also look for evidence of atmospheres around Pluto's moons, as well as other objects in the Kuiper Belt. By separating the different wavelengths of light, ALICE will create an image of the target at each wavelength. ALICE was built by the Southwest Research Institute, Ball Aerospace Corporation, and NASA's Goddard Space Flight Center.
The Radio Science Experiment (REX) will measure the density of the ionosphere, as well as the composition, temperature, and pressure of the atmospheres of Pluto and its moons, as well as Kuiper Belt objects (KBO's). Using an occultation technique to probe Pluto's atmosphere, REX will derive temperature measurements from both the day-side and night-side of the icy dwarf. The instrument will also search for an atmosphere around Charon, and measure the weak radio emissions from Pluto and other bodies the spacecraft encounters. REX was built by the Johns Hopkins University Applied Physics Laboratory (APL), and Stanford University.
The "eagle-eyes" of the spacecraft, the Long Range Reconnaissance Imager (LORRI) will study geology and obtain high-resolution images of the New Horizons encounters. Made especially for the cold temperatures out near Pluto, LORRI is essentially a digital camera attached to a telescope. LORRI will broadcast home to Earth the first high-resolution images of Pluto's surface. At a resolution of at least 50 meters across, (about the size of a football field), LORRI will capture images of craters, search for activity such as geysers, and look for hazes in Pluto's atmosphere. LORRI was built by the Johns Hopkins University Applied Physics Laboratory (APL).
The Solar Wind at Pluto (SWAP) instrument will study how the solar wind interacts with Pluto, its moons, and other Kuiper Belt objects. Built by the Southwest Research Institute (SWRI), the solar wind and plasma spectrometer will also study the amount of Pluto's atmosphere that escapes into space. Information from SWAP will help scientists understand the structure and density of Pluto's atmosphere.ýý
The Pluto Energetic Particle Spectrometer Science Investigation (PEPSSI) will study the density, composition, and nature of energetic particles and plasmas escaping from Pluto's atmosphere. By using PEPSSI to count particles, and knowing how far New Horizons is from Pluto at a given time, scientists will be able to tell how quickly the planet's atmosphere is escaping and learn about the makeup of the icy dwarf's atmosphere. PEPSSI was built by the Johns Hopkins University Applied Physics Laboratory (APL).
The first NASA planetary mission science instrument to be designed, built, and operated solely by students; the Student Dust Counter (SDC) will measure the concentration of dust particles in the outer solar system. SDC will count and measure the sizes and crash rates of dust particles produced by collisions between asteroids, comets, and Kuiper Belt objects. The instrument consists of a detector, which is exposed to the dust particles, and an electronics box that deciphers the mass and speed of the particle.
The SDC will be the first dust detector instrument to travel beyond 18 astronomical units from the Sun (nearly 1.7 billion miles, about the distance from Uranus to the Sun). The SDC data will give scientists their first look at the sources of dust, and how that dust moves within the solar system. SDC was built by students at the Laboratory for Atmospheric and Space Physics at the University of Colorado at Boulder.
New Horizons is the first mission in NASA's New Frontiers Program of medium-class spacecraft exploration projects. Dr. Alan Stern leads the mission and science team as principal investigator; the Johns Hopkins University Applied Physics Laboratory (APL) manages the mission for NASA's Science Mission Directorate. The mission team also includes Ball Aerospace Corporation, the Boeing Company, NASA Goddard Space Flight Center, NASA Jet Propulsion Laboratory (JPL), Stanford University, KinetX Inc. (Navigation team), Lockheed Martin Corporation, University of Colorado, the U.S. Department of Energy, and a number of other firms, NASA centers, and university partners.
Pluto is one of One of the largest and brightest members of the Kuiper Belt, a vast region of ancient, icy, rocky bodies that exist more than a billion miles beyond Neptune's orbit. Pluto orbits the Sun once every 248 Earth years with a highly eccentric orbit that takes it out of the plane of the planets, Pluto's average distance from the Sun is 5.9 billion kilometers (3.7 billion miles), about 40 times farther out than Earth. Pluto's diameter is about two times that of its moon, Charon. In May 2005, the Hubble Space Telescope (HST) found that Pluto has two small satellites circling two to three times farther away from Pluto than Charon.
