New Horizons Team Tuning its Instruments

Status Report: September 25, 2002

The New Horizons instrument payload is years away from peering into the atmosphere of Pluto or snapping detailed pictures of the distant world, its moon, Charon, or the Kuiper Belt Objects beyond. But the work to develop this deep-space scientific toolbox ­ and prepare it for the long journey to edge of our planetary system ­ is well underway.

Last month the New Horizons team completed preliminary design reviews for each instrument. Panels of experts in electronics, optics, device chemistry, charged particle detection, thermal protection, spacecraft structure and other areas ­ pulled from NASA centers, universities and private firms ­ pored over the plans for each instrument and grilled the instrument teams on various aspects of their designs.

"The reviews were very helpful," says William Gibson, New Horizons payload manager, of the Southwest Research Institute (SwRI) in San Antonio. "Each instrument team benefited. There were no fundamental problems with any instrument. Most of the discussions dealt with designing hardware and software for a mission as long as New Horizons. It's one thing to design for something that will orbit Earth for two years, but quite another for a deep space probe on 10- to 15-year mission."

The NASA mission is in initial development. If funded for construction later this year, New Horizons would launch in January 2006, swing around Jupiter for scientific studies and a gravity boost in 2007, reach Pluto as early as 2015, and then visit up to three Kuiper Belt Objects. Its instruments include:

• Pluto Exploration Remote Sensing Investigation (PERSI), a suite of three optical sensors for making visible, infrared and ultraviolet observations, to be built by the Southwest Research Institute, Ball Aerospace and NASA Goddard Space Flight Center.
  
• The Long Range Reconnaissance Imager (LORRI), built by the Johns Hopkins University Applied Physics Laboratory (APL), will provide long-range and high-resolution visible mapping.
  
• Two charged-particle detectors — the Solar Wind Analyzer for Pluto (SWAP) by SwRI and the Pluto Energetic Particle Spectrometer Science Investigation (PEPSSI) from APL — will analyze the materials escaping from Pluto's atmosphere.
  
• REX, the radio science experiment APL is designing with Stanford University, will probe Pluto's atmospheric structure and gauge the average surface temperatures of Pluto and Charon by measuring the intensity of radio signals that reach the spacecraft's 7-foot (2.1 meter) dish antenna.

The instruments are scheduled for completion by summer 2004, after which they'll be integrated with the spacecraft being designed and built at APL. "We are very pleased with the progress," Gibson says. "The teams are working hard, the instrument performance numbers look very promising, and we are on schedule."

New Horizons is the first mission to Pluto, its moon, Charon, and the Kuiper Belt of rocky, icy objects beyond. Principal Investigator Dr. Alan Stern, director of the Southwest Research Institute's Space Studies Department, Boulder, Colo., leads a mission team that includes major partners at the Johns Hopkins University Applied Physics Laboratory in Laurel, Md.; Stanford University, Palo Alto, Calif.; Ball Aerospace Corp., Boulder; NASA Goddard Space Flight Center, Greenbelt, Md.; and the Jet Propulsion Laboratory, Pasadena, Calif. APL manages the mission for NASA and will design, build and operate the New Horizons spacecraft.