NASA’s unmanned spacecraft New Horizons is less than two weeks away from a historic flyby of Pluto and its moons. It is the longest, farthest, and fastest space mission ever. After nine years, three billion miles, and $650 million, New Horizons is expected to reach Pluto on July 14. It is now just a few million miles from the Pluto system, which is very close for a spacecraft that is traveling at 30,000 miles per hour.
The 1,000-pound spacecraft is powered by a single radioisotope thermoelectric generator (RTG) and has a nearly 7–foot-wide antenna dish for radio communications with Earth. Early photos have already excited scientists who are eager to learn more about the “dwarf planet,” which could possibly contain evidence of life.
The spacecraft is carrying seven high-tech instruments that electrical engineers designed to observe Pluto’s composition, atmosphere and moons.
- PEPSSI (Pluto Energetic Particle Spectrometer Science Investigation) is a plasma-sensing spectrometer that measures ions to tell scientists about the composition of Pluto’s atmosphere and how quickly the atmosphere is escaping.
- Alice is an ultraviolet spectrometer used for measuring gas composition, to analyze Pluto’s atmosphere and look for other nearby atmospheres.
- SDC (Student Dust Counter) measures dust impacts at the New Horizons spacecraft during its entire trajectory. It was built and operated by students at the University of Colorado in Boulder.
- Ralph combines an infrared spectrometer and color optical imager to provide color, composition, and thermal maps.
- REX (radio science experiment) is a passive radiometer built by Stanford engineers for measuring atmospheric composition and temperature.
- LORRI (Long Range Reconnaissance Imager) is an optical telescope that provides the highest resolution imaging of the surface. Both REX and LORRI will be used to look for clouds, which could help scientists track Pluto’s winds.
- SWAP (Solar Wind Around Pluto) is a plasma-sensing instrument for measuring the properties of the solar wind at Pluto, the atmospheric escape rate, and for detecting a magnetosphere.