Introducing the New Horizons Instrument Menagerie.

During the first day of the Pluto Science Conference, being held July 22-26, 2013, in Laurel, MD, the conference participants listened to a series of talks describing the rich instrument suite aboard the New Horizons Spacecraft. This entry is just a very brief synopsis of the instruments.

Ralph, Alice, MVIC, LEISA, LORRI, REX, SWAP, PEPSSI, SDC. Those are instrument names and acronyms of the New Horizons science instruments.

New Horizons Instrument SuiteNew Horizons Instrument Suite at a Glance.

LORRI (Long Range Reconnaissance Imager), among many things, “Enables Far-Out Encounter Science. ” That is, at 10 weeks from closest approach, LORRI can observe the Pluto system with spatial resolution better than Hubble. It is a visible camera, equipped with a 1024 x 1024 pixel CCD, with a 0.29 x 0.29 degree field of view (5 microradian pixel iFOV). LORRI also will be used, on approach, for optical navigation. The LORRI Instrument Principal Investigator and Instrument Scientist is Andy Cheng (JHU/APL) and Hal Weaver (JHU/APL), respectively.

Ralph & Alice form New Horizons’  “Remote Science Suite.” Ralph is both a color-imager (MVIC) and an infrared mapping spectrometer (LEISA). Alice is a ultraviolet spectrometer.

Ralph’s MVIC (Multi-Spectral Visible Imaging Camera) consists of seven independent CCD arrays. Four channels are filtered to map blue (400-550 nm), red (540-700 nm), near infrared (780-975 nm) and a narrow methane absorption band (860-910 nm). Six of the MVIC arrays (including all the filter channels) have a 5.7 x 0.037 degree field of view (20 microradian pixel iFOV). LEISA (Linear Etalon Imaging Spectral Array) is a grating spectrometer covering 1.25 to 2.5 microns wavelength range at a resolving power of R~240. A second segment covers 2.1 to 2.25 micron range with a resolving power of R~560. The Ralph Instrument Principal Investigator and Instrument Scientist is Alan Stern (SwRI) and Dennis Reuter (NASA Goddard), respectively.

Alice is an ultraviolet imaging spectrometer. It has two entrance apertures, a large airglow channel and a small SOCC aperture for solar occultation measurements. The entrance slit has two sections, a “box” with a 2.0 x 2.0 degree field of view, and a “stem” with a 0.1 x 4.0 degree field of view. The wavelength coverage spans from 520 to 1870 Angstroms, with a resolution of 3.6 Angstroms.  The Alice Instrument Principal Investigator and Instrument Scientist is Alan Stern (SwRI) and Maarten ver Steeg (SwRI, San Antonio), respectively.

REX, New Horizons’ Radio Science Experiment, is enabled by adding a small amount of signal processing hardware to the existing communication hardware on New Horizons’ main antenna. It will be used, among other observations of Pluto, to showcase a “Different Kind of Radioscience” via 20kW uplink experiments from the DSN during the Pluto and Charon occulations at flyby. The REX Principal Investigator and Instrument Scientist are G.L. Tyler and Ivan Linscott (Stanford University), respectively.

PEPSSI (Pluto Energetic Particle Spectrometer Science Investigation) & SWAP (Solar Wind Around Pluto) are modern particle instruments designed to capture Pluto’s interaction with the solar wind. PEPSSI can measure ions and electrons from 10s of keV to 1 MeV over a 160 x 12 degree fan-shapped beam. SWAP can measure particles with energies 35 eV to 7.5 keV over a 276 x 10 degree field of view. PEPSSI’s Principal Investigator and Instrument Scientist are Ralph Mcnutt (JHU/APL) and Matthew Hill (JHU/APL). SWAP’s Principal Investigaor and Instrument Scientist are David McComas (SwRI, San Antonio) and Heather Elliott (SwRI, San Antonio).

SDC, the Student Dust Counter, designed and built by students at the University of Colorado, Boulder, is “The First Student Experiment on a Deep-Space Probe.” The Principal Investigator is Mihaly Horanyi (University of Colorado). There have been numerous Instrument Scientists, all students at Univ. of Colorado. The current Instrument Scientist is Jamey Szalay. Students continue to be active in supporting data analysis as SDC collects dust rates on its voyage through the solar system. More information about the SDC and the students behind it at

More details about each of the instrument descriptions and performance can be found at
New Horizons Instruments

Locations of the science instruments on the New Horizons Spacecraft