Advanced Very High Resolution Radiometer (AVHRR)
A radiation-detection imager used for
remotely determining ice, snow, and
cloud cover information, and day and
night sea surface temperature (has an
accuracy of 0.5 degrees Celsius)
Array Drive Electronics
An electronics box containing all the elec-
tronics required for operation of the solar
array drive
Battery Modules
Six, located around casing of second stage solid fuel motor
Beacon/Command Antenna (BDA)
Dual-use antenna for receiving commands from ground stations and transmitting
telemetry to ground stations
Earth Sensor Assembly (ESA)
A static, infrared, horizon sensor which provides spacecraft pitch and roll data to the
on-board attitude determination and control subsystem
Equipment Support Module
Contains computers, transmitters, tape recorders, preprocessors, etc.
High Energy Proton and Alpha Particle Detector (HEPAD)
Senses protons and alpha particles in the 379 to 850 keV (thousand electron volts) range
High Resolution Infrared Radiation Sounder (HIRS)
Detects and measures energy emitted in the atmosphere to construct a vertical temper-
ature profile from the Earth’s surface to an altitude of 50 km. It measures incident radia-
tion in 19 spectral regions of the IR spectrum and one visible region. Total ozone, and
water vapor at three levels in the troposphere are measured
Hydrazine Tank
The spacecraft has two tanks containing hydrazine, which is used for thrusting