Earth Sensors
Detects Earth’s horizon (Earth location).
Imager
Five-channel (one visible, four infrared) imaging radiometer
designed to sense radiant and solar reflected energy from Earth.
Provides full Earth scan to mesoscale area scans. Also provides star
sensing capability.
Imager Cooler
Protects the imager from direct sunlight and contamination.
Louver Sun Shields
Passive louver assembly provides cooling during the direct sunlight portion of the orbit. A
sun shield is installed on the Earth-end of the louver system to reduce incident radiation.
Magnetometers
Three-axis magnetometers for measuring the geomagnetic field; only one magnetome-
ter can be powered at any time.
SAR Antenna
Search and Rescue Antenna detects distress signals broadcast by transmitters carried on
general aviation aircraft and beacons aboard some marine vessels. It relays the distress
signal (but cannot pinpoint the location of the signal) to a ground station that dis-
patches assistance.
S-Band Receive Antenna
Full Earth coverage beamwidth, it receives uplink data collection and Weather
Facsimile (WEFAX) transmissions.
S-Band Transmit Antenna
Full Earth coverage beamwidth, it transmits data to the ground segment.
Solar Array
Two panel array that continuously rotates to track the sun during orbital motion, pro-
viding primary power for the satellite.
Solar Sail
Conical-shaped sail mounted on a 17 meter (58 foot) boom balances the torque
caused by solar radiation pressure on the solar array.