Personal tools
You are here: GES DISC Home UARS Documents

UARS Instruments and Data Documents

NASA's Upper Atmosphere Research Satellite (UARS) was launched on September 12, 1991, from the Space Shuttle Discovery (STS-48). It was released three days later into a 585 km altitude orbit, inclined 57 degrees to the equator. UARS satellite was outfitted with 9 instruments  designed to provide the first simultaneous, comprehensive, global coverage of upper atmosphere composition, dynamics, and energy input data.  This includes the study of the physical and chemical processes of the Earth's stratosphere, mesosphere, and lower thermosphere. Four instruments (CLAES, ISAMS, MLS, HALOE) were designed to measure atmospheric composition and temperature, other two instruments (HRDI, WINDII) were used to observe atmospheric winds, and three others (SOLSTICE, SUSIM, PEM) measured the energy inputs from solar radiation and charged particles. A tenth instrument (ACRIM II) was added to take advantage of a flight of opportunity to continue NASA's solar constant measurements.


Cryogenic Limb Array Etalon Spectrometer (CLAES)


Halogen Occultation Experiment (HALOE)

High-Resolution Doppler Imager (HRDI)

Improved Stratospheric and Mesospheric Sounder (ISAMS)

Microwave Limb Sounder (MLS)

Particle Environment Monitor (PEM)

Solar-Stellar Irradiance Comparison Experiment (SOLSTICE)

Solar Ultraviolet Spectral Irradiance Monitor (SUSIM)

Wind Imaging Interferometer (WINDII)

Correlative NMC and UKMO

Platform Overview

Platform Long Name, Acronym

Upper Atmosphere Research Satellite, UARS 

Collection Environment

Data are collected from a near circular Earth orbit of about 585 km altitude and 57 degree inclination. 

Platform Program Management

The UARS program is managed by the UARS project


Platform Mission Objectives

It is the UARS mission to study the coupled energy inputs, chemistry and dynamics of the upper atmosphere, improve the understanding of natural and man-made perturbations to the upper atmosphere, and to learn more about long term climate effects. The mission objectives also include the study of energy input and loss, photochemistry, and dynamics in the upper atmosphere, coupling among these processes, and coupling between the upper and lower atmosphere.


Platform Parameters
Launch Vehicle:  Space Shuttle Discovery (STS-48)
Launch Date:  12 September 1991 23:11:04 GMT
Orbit:  585 km (near circular)
Inclination:  57 deg
Period:  96 minutes
Instrument mass:  2400 kg
Total spacecraft mass: 6540 kg
Spacecraft length:  10.7 m
Instrument power:  750 W
Total power:  1600 W
Mission lifetime:  3 years
Manufacturer:  General Electric Astro-Space Division
Sponsoring Agency:  NASA
Coverage Information
Latitude coverage 

80° North to 80° South

Global coverage interval  36 days for full diurnal measurements
Attitude Characteristics
Attitude control:  0.01 deg precision (1 sigma)
Data Collection System
Data rate:  32 kbit/s
Data storage:  Two tape recorders
Playback rate:  512 kbit/s
Data relay:  TDRSS, 15 min/orbit

The near complete latitude coverage is achieved by performing a yaw maneuver approximately every 36 days, whereby the spacecraft is rotated 180 degrees to view in the opposite hemisphere along the trajectory path. Thus, coverage is increased from a range of 34S - 80N to a range of 80S - 80N.

Communications Links

Tracking and Data Relay Satellite System (TDRSS)

List of Available Guide Documents for Instruments

  1. CryogenicLimb Array Etalon Spectrometer (CLAES)
  2. Halogen Occultation Experiment (HALOE)
  3. High Resolution Doppler Imager (HRDI)
  4. Improved Stratospheric and Mesospheric Sounder (ISAMS)
  5. Microwave Limb Sounder (MLS)
  6. Particle Environment Monitor (PEM)
  7. Solar-Stellar Irradiance Comparison Experiment (SOLSTICE)
  8. Solar Ultraviolet Spectral Irradiance Monitor (SUSIM)
  9. Wind Imaging Interferometer (WINDII)
  10. Active Cavity Radiometer Irradiance Monitor (ACRIM II) (see note below)

NOTE: ACRIM II is not managed by the UARS project

Ground Segment Information

Tracking and Control

UARS command and control are coordinated through the Project Operations Control Center (POCC) located at Goddard Space Flight Center (GSFC). Communications between the ground system and UARS are normally made through the Space Network S-Band Single Access (SSA) service. Contacts between UARS and the Tracking and Data Relay Satellite (TDRS) are made for a minimum of 10 minutes on each orbit. In emergencies, direct links between UARS and Deep Space Network (DSN) ground stations will be used.

Data Acquisition and Processing

Data are telemetered from UARS through the Tracking and Data Relay Satellite System (TDRSS) to the Data Capture Facility (DCF) at NASA GSFC. There the data are checked and forwarded to the UARS Central Data Handling Facility (CDHF). The instrument PI teams are connected to the CDHF through remote analysis computers (RACs), where they have developed software to convert the raw data to processed data. The CDHF uses the production software to convert the level 0 data to level 1, 2, 3A and 3B. The data are stored on line, and cataloged at the CDHF. The instrument PI teams are responsible for the quality of the data and updating the data.

Latitude Crossing Times

There are approximately 15 orbits (97 minute period) each day, for a maximum of 30 crossings at each latitude between 80 north and 80 south.



  1. Evaluation of the UARS Data, Reprinted from the Journal of Geophysical Research, American Geophysical Union publication, 1996
  2. Reber, Carl A., The Upper Atmosphere Research Satellite, EOS Trans. AGU, 71, 1867, 1990.
  3. Reber, C. A., C. E. Trevathan, R. J. McNeal, and M. R. Luther, The Upper Atmosphere Research Satellite (UARS) Mission, J. Geophys. Res. 98, D6, 10643-10647, 1993.
  4. Geophysical Research Letters, Vol. 20, 1993.
  5. Upper Atmosphere Research Satellite, A Program to Study Global Ozone Change, NASA publication, 1989.
  6. Mission Operations Report, Upper Atmosphere Research Satellite (UARS), NASA Report S-678-48-91-01.
  7. Additional UARS documentation can be located using the UARS Publication Search page.

Glossary of Terms

The platform is a source from where data are taken. The platform may be an aircraft, balloon, buoy, ground station, or spacecraft. The UARS platform contains a collection of instruments, power system, and communications systems.

List of Acronyms

ACRIM Active Cavity Radiometer Irradiance Monitor
CDHF  Central Data Handling Facility
CLAES  Cryogenic Limb Array Etalon Spectrometer
DCF  Data Capture Facility
DSN  Deep Space Network
GMT  Greenwich Mean Time (also Universal Time, UT)
GSFC  Goddard Space Flight Center
HALOE  Halogen Occultation Experiment
HRDI  High Resolution Doppler Imager
ISAMS  Improved Stratospheric and Mesospheric Sounder
kg  kilogram
km  kilometer
MLS  Microwave Limb Sounder
NASA  National Aeronautics and Space Administration
PEM  Particle Environment Monitor
POCC  Project Operations Control Center
RAC  remote analysis computer
SOLSTICE  Solar/Stellar Irradiance Comparison Experiment
SUSIM  Solar Ultraviolet Spectral Irradiance Monitor
TDRS  Tracking and Data Relay Satellite
TDRSS  Tracking and Data Relay Satellite System
UARS  Upper Atmosphere Research Satellite
WINDII  Wind Imaging Interferometer

Document Information

Change History

Version 2.0
Version baselined on addition to the GES Controlled Documents List, January, 30, 1998.
Document Actions
NASA Logo -
NASA Privacy Policy and Important Notices
Last updated: Feb 28, 2014 06:10 PM ET