The science payload for NASA's New Horizons mission completed its last major preparations for flight last week. The probe will be the first to visit Pluto and its moon, Charon.
The compact New Horizons spacecraft carries a payload of seven science instruments for examining the geology, composition, surface, temperature and atmospheric structure of the planet and its moon.
Flybys of one or more of the icy objects in the Kuiper Belt may be scheduled thereafter, during a mission extension.
Southwest Research Institute (SwRI) led the development of the science payload, which recently completed a series of spacecraft environmental tests in Maryland at NASA's Goddard Space Flight Center and the Johns Hopkins University Applied Physics Laboratory (APL), where the instruments were also integrated with the spacecraft.
"Although the hard work on the instrument development and testing is over, the work never stops," says New Horizons Science Payload Manager William C. Gibson, assistant vice president of the SwRI Space Science and Engineering Division. "We'll only stop worrying once we've achieved full mission success, but we're thrilled that the payload is ready for flight."
The New Horizons payload is incredibly power efficient, with the instruments collectively drawing only about 28 watts. The payload consists of three optical instruments, two plasma instruments, a dust sensor and a radio science receiver/radiometer. The individual instruments and their principal investigators (PI) are:
Alice, an ultraviolet imaging spectrometer that will probe the atmospheric composition and structure of Pluto. (Led by SwRI; PI Dr. Alan Stern)
Ralph, a visible and infrared camera that will obtain high-resolution color maps and surface composition maps of the surfaces of Pluto and Charon. (Led by Ball Aerospace and SwRI; PI Dr. Alan Stern)
LORRI, or Long Range Reconnaissance Imager, will image Pluto's surface at football-field sized resolution, resolving features as small approximately 50 yards across. (Led by APL; PI Dr. Andrew Cheng)
The New Horizons spacecraft carries seven science instruments, including:
Alice (also shown in accompanying photo) ¿ an ultraviolet imaging spectrometer that will probe the atmospheric composition and structure of Pluto.
Ralph ¿ a visible and infrared camera that will obtain high-resolution color maps and surface composition maps of the surfaces of Pluto and Charon.
LORRI, or Long Range Reconnaissance Imager ¿ will image Pluto's surface at football-field sized resolution, resolving features as small approximately 50 yards across.
SWAP, or Solar Wind Around Pluto ¿ will measure charged particles from the solar wind near Pluto to determine whether it has a magnetosphere and how fast its atmosphere is escaping.
PEPSSI, or Pluto Energetic Particle Spectrometer Science Investigation ¿ will search for neutral atoms that escape the planet's atmosphere and subsequently become charged by their interaction with the solar wind.
SDC, or Student Dust Counter ¿ will count and measure the masses of dust particles along the spacecraft's entire trajectory, covering regions of interplanetary space never before sampled.
REX, or Radio Science Experiment ¿ a circuit board containing sophisticated electronics that has been integrated with the spacecraft's radio telecommunications system, will study Pluto's atmospheric structure, surface thermal peperties, and make measurements of the mass of Pluto and Charon and KBOs.
