NEAR Instruments

Multispectral Imaging System (MIS)

Lead Institution: APL

Optical System

- f/3.4, five element refractor
- FOV 3 x 2.25 degrees
- Eight position filter wheel

CCD Focal Plane Unit

- 0.4 - 1.0 spectral range
- 244 x 550 px format (244 x 537 used)
- 16 x 27 pixels, 161 x 95 r resolution
- 1 sec frame rate
- 10 ms to 1 sec exposure, electronic shutter
- Operating temperature: -40C to -30 C (noise less than 150 e-/px)

Near-IR Spectrograph (NIS)

Lead Institutions: SSG, EG&G, APL

- Spectral range ~0.8-2.6 , covered in 62 spectral channels
- Spectral channels are spatially co-registered
- Spectrum dispersed onto Ge and InGaAs line array detectors
- S/N greater than 200
- Operating temperature less than - 30 C
- Instrument includes a 1-D scan mirror FOV can be boresighted with imager or scanned greater than 90 degrees away
- Slit IFOV 0.38 x 0.76 degrees

Multispectral Imager/Near-Infrared Spectrograph Instrument Scientist: Scott L. Murchie
Science Team:
Joseph Veverka (Team Leader), Cornell University, Ithaca, N.Y.
James F. Bell III, NASA Ames Research Center, Mountain View, Calif.
Clark R. Chapman, Planetary Science Institute, Tucson, Ariz.
Michael C. Malin, Malin Space Science Systems, Inc., San Diego, Calif.
Lucy-Ann A. McFadden, University of Maryland, College Park, Md.
Mark S. Robinson, U.S. Geological Survey, Flagstaff, Ariz.
Peter C. Thomas, Cornell University

X-ray/Gamma Ray Spectrometer (XGRS)

Lead Institution: NASA/GSFC

X-Ray Fluorescence (XRF)

- The XRF detectors are three gas proportional counters collimated to 5 degrees FOV, observing X-ray line emissions from the asteroid.
- Balanced filters are used to separate Si, Al, Mg.
- Detectors resolve Fe, S, Ca lines.
- XRF includes a separate solar monitor.

Gamma Ray Spectrometer (GRS)

- Shielded NaI scintillator GRS is body-mounted and will measure radioactive elements (e.g. U, K, Th) plus other important elements (e.g. H, Fe, Mg, Si).

X-Ray/Gamma-Ray Spectrometer Instrument Scientist: Ralph L. McNutt
Science Team:
Jacob I. Trombka (Team Leader), NASA Goddard Space Flight Center, Greenbelt, Md.
William V. Boynton, University of Arizona, Tucson
Johannes Bruckner, Max Planck Institut fur Chemie, Mainz, Germany
Steven W. Squyres, Cornell University

Fluxgate Magnetometer (MAG)

Lead Institution: NASA/GSFC

- Three-axis fluxgate sensor on the feed of the high-gain antenna
- Eight ranges: Full scale, 6 nT to 100,000 nT Resolution, 16 bit
- Outputs, once per second: DC field Bandpassed AC, 1.0 to 10.0 Hz
- System sensitivity: less than 5 nT (local field)
- Asteroid surface field to be measured to 40 nT using asteroid rotation and spacecraft orbital motion

Magnetometer Instrument Scientist: Larry J. Zanetti
Science Team:
Mario H. Acuna, Goddard Space Flight Center (Team Leader)
Christopher T. Russell, University of California, Los Angeles

Light Imaging Detector and Ranger (LIDAR)

Lead Institutions: APL, MDD

- Fixed mount on spacecraft and bore-sighted with imager
- Diode pumped, Nd:YAG laser transmitter at 1.064 m
- Direct, incoherent detection with enhanced Si APD
- Range measurements at 1/sec
- Maximum range 50 km
- Range accuracy 6 m
- Beam divergence less than 400 r

Laser Altimeter Instrument Scientist: Andrew F. Cheng
Science Team:
Maria T. Zuber (Team Leader), Goddard Space Flight Center

Radio Science

- Uses spacecraft telemetry system
- Two-way Doppler to 0.1 mm/s

Radio Science Science Team:
Donald K. Yeomans (Team Leader), NASA Jet Propulsion Laboratory Pasadena, Calif.
Jean-Pierre Barriot, Centre National D'Etudes Spatiales, Toulouse, France
Alexander S. Konopoliv, Jet Propulsion Laboratory

Examples of Instrument data transmission rates

	         One 34m pass/day       Three 34m passes/day
Instrument  Example 1   Example 2   Example 3   Example 4

Imager        1500         650        5300        4650

IR              50         800         200         800

XR             200         250         250         250

GRS            100         150         150         150

MAG             50          50          50          50

LIDAR           50          50           0          50

S/C HK          50          50          50          50

TOTAL         2000        2000        6000        6000

Units are daily average bits per second
Instrument information courtesy of Andrew F. Cheng, Project Scientist,

Dr. David R. Williams,
NSSDCA, Mail Code 690.1
NASA Goddard Space Flight Center
Greenbelt, MD 20771

NASA Official: Dr. David R. Williams,
Last Updated: 08 February 2000, DRW