PDS_VERSION_ID                = PDS3
RECORD_TYPE                   = STREAM

OBJECT                        = INSTRUMENT_HOST
INSTRUMENT_HOST_ID            = LP

OBJECT                        = INSTRUMENT_HOST_INFORMATION
INSTRUMENT_HOST_NAME          = "LUNAR PROSPECTOR"
INSTRUMENT_HOST_TYPE          = SPACECRAFT
INSTRUMENT_HOST_DESC          = "

Instrument Host Overview
========================
 
Lunar Prospector (LP) is a small, simple, spin-stabilized spacecraft
with minimal operational requirements [BINDERETAL1998].  Its fueled
mass is 305 kg.  The spacecraft bus is a graphite-epoxy drum that is
1.37 m in diameter and 1.28 m tall.  Power is provided by solar cells
mounted on the surface of the bus assembly, which produce an average
of 186 w.  There is also a rechargeable, 4.8 amp-hr NiCd battery for
power during night side passes.  The science instruments are mounted
on three 2.5 m booms.  The Gamma Ray Spectrometer is mounted on one
boom, the Neutron Spectrometer and Alpha Particle Spectrometers are
mounted on another boom, and the Magnetometer and Electron
Reflectometer are mounted on the third boom.  The Magnetometer
instrument is mounted on a 1.2 m long boom extending beyond the main
boom to isolate it from the Electron Reflectometer.

The spacecraft bus houses three fuel tanks, six engines, and five
electronic units.  The fuel tanks at launch hold 138 kg of hydrazine
pressurized with helium.  There are two aft axial engines, two forward
axial engines, and two tangential engines.

The communication system consists of an S-band transponder, an omni
antenna with 3-pi steradian antenna pattern for uplink and downlink,
and a medium gain antenna for downlink.  The engineering-only downlink
data rate is 300 bps and the science/engineering downlink data rate is
3600 bps.

Command and control of the spacecraft is achieved by a simple Command
and Data Handling (C&DH) unit.  As an individual command is uplinked
to the spacecraft, the C&DH directs the command to the appropriate
subsystem.  All science and engineering data are collected by the C&DH
and then are buffered and formatted for downlink by the C&DH.  The
data are downlinked at 1800 bps immediately and simultaneously dumped
into a solid state recorder.  The data stored on the solid state
recorder is downlinked 53 minutes later.  These delayed data frames
are interleaved into the real-time data stream, yielding a total
downlink rate of 3600 bps.  The purpose of the delayed stream is to
receive data acquired during communications blackout periods and to
eliminate the need for a commandable data recorder.

Science Packages
================

The Lunar Prospector spacecraft has five science instruments.  The
instruments are a Gamma Ray Spectrometer (GRS), a Neutron Spectrometer
(NS), an Alpha Particle Spectrometer (APS), a Magnetometer (MAG), and
an Electron Reflectometer (ER).  A Doppler Gravity Experiment (DGE)
uses Doppler tracking data for deriving gravity measurements.  In
addition, the spacecraft spin rate and attitude are determined on the
ground from data derived from a sun sensor and an IR Earth/Moon limb
crossing sensor.  "

END_OBJECT                   = INSTRUMENT_HOST_INFORMATION

OBJECT                       = INSTRUMENT_HOST_REFERENCE_INFO
  REFERENCE_KEY_ID           = "BINDERETAL1998"
END_OBJECT                   = INSTRUMENT_HOST_REFERENCE_INFO

END_OBJECT                   = INSTRUMENT_HOST
END