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 will study the physical and chemical processes of the Earth's stratosphere, mesosphere, and lower thermosphere. Four instruments (CLAES, ISAMS, MLS, HALOE) measure atmospheric composition and temperature, two instruments (HRDI, WINDII) observe atmospheric winds, and three other instruments (SOLSTICE, SUSIM, PEM) measure the energy inputs from solar radiation and charged particles. A tenth instrument (ACRIM II) will take advantage of a flight of opportunity to continue NASA's solar constant measurements.
Table of Contents
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
- CryogenicLimb 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)
- 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.
References
Evaluation of the UARS Data, Reprinted from the Journal of Geophysical Research, American Geophysical Union publication, 1996
Reber, Carl A., The Upper Atmosphere Research Satellite, EOS Trans. AGU, 71, 1867, 1990.
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.
Geophysical Research Letters, Vol. 20, 1993.
Upper Atmosphere Research Satellite, A Program to Study Global Ozone Change, NASA publication, 1989.
Mission Operations Report, Upper Atmosphere Research Satellite (UARS), NASA Report S-678-48-91-01.
Glossary of Terms
- Platform
-
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 |
| m | meter |
| 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 |
| W | watt |
| WINDII | Wind Imaging Interferometer |
Change History
- Version 2.0
- Version baselined on addition to the GES Controlled Documents List, January, 30, 1998.
Atmos Composition
