NOAA-6

NOAA-6
Name	NOAA-6
Mission type	Weather satellite
Operator	National Oceanic and Atmospheric Administration (NOAA), National Aeronautics and Space Administration (NASA)
Cospar id	1979-100A
Satcat	11844
Spacecraft type	TIROS Operational Vertical Sounder series
Manufacturer	Ford Aerospace / GE Aerospace
Launch mass	719 kg
Launch date	1979-06-27
Launch rocket	Delta 2910
Launch site	Vandenberg Air Force Base Space Launch Complex 2
Orbit reference	Geocentric orbit
Orbit regime	Sun-synchronous orbit
Orbit periapsis	828 km
Orbit apoapsis	846 km
Orbit inclination	98.7°
Instrument	Advanced TIROS-N, AVHRR/1, TOVS suite, SARSAT payload

NOAA-6 was an American polar-orbiting environmental satellite launched in 1979 as part of the TIROS Operational Vertical Sounder (TOVS) program. It provided global meteorology observations used by National Weather Service forecasters, Naval Research Laboratory scientists, and international partners including European Space Agency and Japan Meteorological Agency. The mission continued the operational heritage from the TIROS and NOAA series, supporting weather forecasting and climate monitoring activities across civilian and defense institutions.

Mission and Objectives

The principal objectives were to collect global atmospheric temperature and humidity profiles, monitor cloud distribution, provide data for numerical weather prediction models, and support search and rescue through the international COSPAS-SARSAT program. The mission aimed to extend capabilities demonstrated by TIROS-N and the Operational Vertical Sounder program, provide continuity for the Advanced Very High Resolution Radiometer calibration, and contribute to long-term climate data records used by Intergovernmental Panel on Climate Change assessments. Operational users included the National Oceanic and Atmospheric Administration, National Aeronautics and Space Administration, United States Air Force, and international meteorological agencies such as the UK Met Office and Météo-France.

Spacecraft and Instruments

The spacecraft bus followed the TIROS-N design heritage produced by aerospace contractors including Fairchild Industries and Ford Aerospace. Key instruments comprised the Advanced Very High Resolution Radiometer (AVHRR/1) for visible and infrared imaging, the TIROS Operational Vertical Sounder (TOVS) suite containing the High-resolution Infrared Radiation Sounder (HIRS/2) and the Microwave Sounding Unit (MSU), an Image Dissector Camera System (IDCS), and a Search and Rescue Satellite-Aided Tracking (SARSAT) beacon. The payload enabled measurements across spectral bands utilized by the European Centre for Medium-Range Weather Forecasts, National Centers for Environmental Prediction, and research groups at NOAA's National Environmental Satellite, Data, and Information Service (NESDIS). Onboard systems included stabilization from momentum wheels, power from solar arrays, and telemetry via Telemetry and Command links compatible with Tracking and Data Relay Satellite System concepts and ground stations like those at Fairbanks and Wallops Flight Facility.

Launch and Orbit

NOAA-6 launched on 27 June 1979 aboard a Delta 2910 rocket from Vandenberg Air Force Base Space Launch Complex 2. The insertion placed the satellite into a retrograde sun-synchronous orbit with an inclination of 98.7°, enabling consistent local solar time sampling for the AVHRR and TOVS instruments similar to the sampling strategies used by LANDSAT and SPOT missions. The orbital parameters—apogee around 846 km and perigee near 828 km—facilitated global coverage with repeat cycles exploited by operational centers including Joint Typhoon Warning Center and the National Hurricane Center for tropical cyclone monitoring. Tracking and command responsibilities were shared among NOAA ground networks and Air Force Satellite Control Facility assets.

Operations and Performance

Throughout its operational life, the spacecraft provided routine AVHRR imaging for cloud and surface monitoring, and delivered TOVS-derived temperature and humidity soundings critical for model initialization at agencies such as European Centre for Medium-Range Weather Forecasts and Canadian Meteorological Centre. The SARSAT payload relayed distress beacon signals that assisted United States Coast Guard and international search-and-rescue authorities. Data distribution leveraged networks like the World Meteorological Organization Global Telecommunication System and supported assimilation efforts in models developed by ECMWF and NCEP. Performance issues typical of the era—sensor degradation, on-orbit calibration drifts, and attitude control corrections—were managed by NESDIS engineers in coordination with contractors including RCA Astro Electronics and Hughes Aircraft Company.

Scientific and Operational Results

NOAA-6 contributed to daily weather analysis, seasonal monitoring, and retrospective climate studies used by agencies such as NOAA National Climatic Data Center and research groups at institutions like Scripps Institution of Oceanography and NASA Goddard Space Flight Center. AVHRR data supported sea surface temperature mapping used by National Marine Fisheries Service and oceanographers at Woods Hole Oceanographic Institution for studies of El Niño–Southern Oscillation events. TOVS soundings fed into numerical weather prediction improvements credited by European Centre for Medium-Range Weather Forecasts and operational forecasters at Joint Centre for Satellite Data Assimilation. SARSAT detections aided air and maritime rescue cases coordinated through International Maritime Organization channels. The mission's datasets were archived and later used in intercomparison studies with instruments on ERS-1, NOAA-7, and Metop platforms.

Decommissioning and Legacy

After completing its primary mission and extended operations, the satellite was retired and placed into a disposal regime consistent with long-term orbital stewardship practices acknowledged by organizations such as the Inter-Agency Space Debris Coordination Committee and the United Nations Office for Outer Space Affairs. NOAA-6's heritage influenced the design of subsequent polar-orbiting systems like the Polar Operational Environmental Satellites and the Metop series developed by EUMETSAT. Its data continuity supported climate records relied upon by the Intergovernmental Panel on Climate Change and research communities at institutions including Massachusetts Institute of Technology, University of California, Los Angeles, and Princeton University. The mission remains cited in archival studies by National Academy of Sciences panels and in technical reports from NASA Goddard Space Flight Center and NESDIS.

Category:Weather satellites Category:1979 in spaceflight