New Horizons is designed to retain heat like a thermos bottle. The spacecraft is covered in lightweight, goldcolored, multilayered thermal insulation blankets, which hold in heat from operating electronics to keep the spacecraft warm. Heat from the electronics will keep the spacecraft operating at between 10-30 degrees Celsius (about 50-85 degrees Fahrenheit) throughout the journey. New Horizons’ sophisticated, automated heating system monitors power levels inside the craft to make sure the electronics are running at enough wattage to maintain safe temperatures. Any drop below that operating level (about 150 watts) and it will activate small heaters around the craft to make up the difference. When the spacecraft is closer to Earth and the Sun, louvers (that act as heat vents) on the craft will open when internal temperatures are too high.
New Horizons needs less power than a pair of 100-watt light bulbs to complete its mission at Pluto. On average, each of the seven science instruments uses between 2 and 10 watts – about the power of a night light – when turned on.
The payload is incredibly power efficient – with the instruments collectively drawing less than 28 watts – and represent a degree of miniaturization that is unprecedented in planetary exploration. The instruments were designed specifically to handle the cold conditions and low light levels at Pluto and in the Kuiper Belt beyond.
Alice
Mass: 4.5 kilograms (9.9 pounds) Average Power: 4.4 watts Development: Southwest Research Institute Principal Investigator: Alan Stern, Southwest Research Institute Purpose: Study atmospheric composition and structure Alice is a sensitive ultraviolet imaging spectrometer designed to probe the composition and structure of Pluto’s dynamic atmosphere. A spectrometer separates light into its constituent wavelengths (like a prism). An “imaging spectrometer” both separates the different wavelengths of light and produces an image of the target at each wavelength.
Ralph
Mass: 10.3 kilograms (22.7 pounds) Average Power: 6.3 watts Development: Ball Aerospace Corporation, NASA Goddard Space Flight Center, Southwest Research Institute Principal Investigator: Alan Stern, Southwest Research Institute Purpose: Study surface geology and morphology; obtain surface composition and surface temperature maps
Radio Science Experiment (REX)
Mass: 100 grams (3.5 ounces) Average Power: 2.1 watts Development: Johns Hopkins University Applied Physics Laboratory, Stanford University Principal Investigator: Len Tyler, Stanford University Purpose: Measure atmospheric temperature and pressure (down to the surface); measure density of the ionosphere; search for atmospheres around Charon and other KBOs
Long Range Reconnaissance Imager (LORRI)
Mass: 8.8 kilograms (19.4 pounds) Average Power: 5.8 watts Development: Johns Hopkins University Applied Physics Laboratory Principal Investigator: Andy Cheng, Applied Physics Laboratory Purpose: Study geology; provide high-resolution approach and highest-resolution encounter images
Solar Wind at Pluto (SWAP)
Mass: 3.3 kilograms (7.3 pounds) Average Power: 2.3 watts Development: Southwest Research Institute Principal Investigator: David McComas, Southwest Research Institute Purpose: Study solar wind interactions and atmospheric escape
Pluto Energetic Particle Spectrometer Science Investigation (PEPSSI)
Mass: 1.5 kilograms (3.3 pounds) Average Power: 2.5 watts Development: Johns Hopkins University Applied Physics Laboratory Principal Investigator: Ralph McNutt Jr., Applied Physics Laboratory Purpose: Study the density, composition, and nature of energetic particles and plasmas resulting from the escape of Pluto’s atmosphere
Student Dust Counter (SDC)
Mass: 1.9 kilograms (4.2 pounds) Average Power: 5 watts Development: Laboratory for Atmospheric and Space Physics, University of Colorado at Boulder Principal Investigator: Mihaly Horanyi, University of Colorado at Boulder Purpose: Measure concentration of dust particles in outer solar system