NOAA-7, known as NOAA-C before launch, was an American operational weather satellite for use in the National Operational Environmental Satellite System (NOESS) and for the support of the Global Atmospheric Research Program (GARP) during 1978-1984. The satellite design provided an economical and stable Sun-synchronous platform for advanced operational instruments to measure the atmosphere of Earth, its surface and cloud cover, and the near-space environment.[5] An earlier launch, NOAA-B, was scheduled to become NOAA-7, however NOAA-B failed to reach its required orbit.[6]
Names | NOAA-C | ||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|
Mission type | Weather | ||||||||||
Operator | NOAA | ||||||||||
COSPAR ID | 1981-059A | ||||||||||
SATCAT no. | 12553 | ||||||||||
Mission duration | 2 years (planned) 5 years (achieved) | ||||||||||
Spacecraft properties | |||||||||||
Spacecraft type | TIROS | ||||||||||
Bus | TIROS-N[1] | ||||||||||
Manufacturer | RCA Astro Electronics | ||||||||||
Launch mass | 1,418 kg (3,126 lb) [2] | ||||||||||
Dry mass | 735 kg (1,620 lb) | ||||||||||
Start of mission | |||||||||||
Launch date | 23 June 1981, 10:52:59 UTC[3] | ||||||||||
Rocket | Atlas F-Star-37S-ISS (Atlas S/N 87F) | ||||||||||
Launch site | Vandenberg, SLC-3W | ||||||||||
Contractor | Convair | ||||||||||
End of mission | |||||||||||
Disposal | Decommissioned | ||||||||||
Deactivated | June 1986 | ||||||||||
Orbital parameters | |||||||||||
Reference system | Geocentric orbit[4] | ||||||||||
Regime | Sun-synchronous orbit | ||||||||||
Perigee altitude | 845 km (525 mi) | ||||||||||
Apogee altitude | 863 km (536 mi) | ||||||||||
Inclination | 98.90° | ||||||||||
Period | 102.00 minutes | ||||||||||
| |||||||||||
Launch
editThe launch of NOAA-7 took place at 10:52:59 UTC on 23 June 1981 from Space Launch Complex 3W (SLC-3W) at the Vandenberg Air Force Base in California. NOAA-7 was launched atop an Atlas F launch vehicle with a Star-37S upper stage.
Spacecraft
editThe NOAA-7 satellite had a mass of 1,418 kg (3,126 lb). The satellite was based upon the DMSP Block 5D satellite bus developed for the U.S. Air Force, and it was capable of maintaining an Earth-pointing accuracy of better than ± 0.1° with a motion rate of less than 0.035 degrees/second.[5]
Instruments
editPrimary sensors included the Advanced Very High Resolution Radiometer (AVHRR/2) for global cloud cover observations, and the TIROS Operational Vertical Sounder (TOVS) suite for atmospheric temperature and water profiling. Secondary experiments consisted of a Space Environment Monitor (SEM) measuring proton and electron fluxes, and the Data Collection and Platform Location System (DCPLS) for relaying data from balloons and ocean buoys for the Argos system. The TOVS suite consists of three subsystems: the High Resolution Infrared Radiation Sounder 2 (HIRS/2), the Stratospheric Sounding Unit (SSU), and the Microwave Sounding Unit (MSU).[5]
Advanced Very High Resolution Radiometer
editThe NOAA 7 Advanced Very High Resolution Radiometer (AVHRR/2) was a four-channel scanning radiometer capable of providing global daytime and nighttime sea-surface temperature and information about ice, snow, and clouds. These data were obtained on a daily basis for use in weather analysis and forecasting. The multispectral radiometer operated in the scanning mode and measured emitted and reflected radiation in the following spectral intervals: channel 1 (visible), 0.55 to 0.90 micrometer (
TIROS Operational Vertical Sounder
editThe TIROS Operational Vertical Sounder (TOVS) consisted of three instruments: the High-resolution Infrared Radiation Sounder modification 2 (HIRS/2), the Stratospheric Sounding Unit (SSU), and the Microwave Sounding Unit (MSU). All three instruments were designed to determine radiances needed to calculate temperature and humidity profiles of the atmosphere from the surface to the stratosphere (approximately 1 mb). The HIRS/2 instrument had 20 channels in the following spectral intervals: channels 1 through 5, the 15-micrometer (
Data Collection and Platform Location System
editThe Data Collection and Platform Location System (DCPLS) on NOAA-7, also known as Argos, was designed and built in France to meet the meteorological data needs of the United States and to support the Global Atmospheric Research Program (GARP). The system received low-duty-cycle transmissions of meteorological observations from free-floating balloons, ocean buoys, other satellites, and fixed ground-based sensor platforms distributed around the globe. These observations were organized on board the spacecraft and retransmitted when the spacecraft came within range of a Command and Data Acquisition (CDA) station. For free-moving balloons, the Doppler frequency shift of the transmitted signal was observed to calculate the location of the balloons. The DCPLS was expected, for a moving sensor platform, to have a location accuracy of 3 to 5 km, and a velocity accuracy of 1.0 to 1.6 m/s. This system had the capability of acquiring data from up to 4000 platforms per day. Identical experiments were flown on other spacecraft in the TIROS-N/NOAA series. Processing and dissemination of data were handled by CNES in Toulouse, France.[9]
Space Environment Monitor
editThe Space Environmental Monitor (SEM) was an extension of the solar proton monitoring experiment flown on the ITOS spacecraft series. The object was to measure proton flux, electron flux density, and energy spectrum in the upper atmosphere. The experiment package consisted of three detector systems and a data processing unit. The Medium Energy Proton and Electron Detector (MEPED) measured protons in five energy ranges from 30 keV to >2.5 MeV; electrons above 30, 100, and 300 keV; protons and electrons (inseparable) above 6 MeV; and omni-directional protons above 16, 36, and 80 MeV. The High-Energy Proton Alpha Telescope (HEPAT), which had a 48° viewing cone, viewed in the anti-Earth direction and measured protons in four energy ranges above 370 MeV and alpha particles in two energy ranges above 850 MeV/nucleon. The Total Energy Detector (TED) measured electrons and protons between 300 eV and 20 keV.[10]
Science objectives
edit- Day and night observation of global cloud cover.
- Observation of atmospheric water/temperature profile.
- Monitoring particle flux in the near-Earth environment.
Mission
editNOAA-7 was withdrawn from use in June 1986 after its power system malfunctioned.[11] In August 1997, the decommissioned satellite experienced an abrupt 1 second change in orbital period. At the same time 3 new debris particles were observed. It is unclear if this was caused by an internal release of energy or collision with an unidentified object.[12] As of 8 December 2013, the derelict satellite remains in a 834 by 850 km (518 by 528 mi) orbit, inclined at 98.87° and with a period of 101.62 minutes.[13]
References
edit- ^ "Tiros N". Encyclopedia Astronautica. Archived from the original on 28 December 2016. Retrieved 15 January 2017.
- ^ "NOAA-6". World Meteorological Organization (WMO). 28 July 2015. Retrieved 31 December 2020.
- ^ McDowell, Jonathan. "Launch Log". Jonathan's Space Report. Retrieved 27 December 2020.
- ^ "Trajectory: NOAA 7 1981-059A". NASA. 14 May 2020. Retrieved 27 December 2020. This article incorporates text from this source, which is in the public domain.
- ^ a b c "Display: NOAA-7 1981-059A". NASA GSFC. 14 May 2020. Retrieved 31 December 2020. This article incorporates text from this source, which is in the public domain.
- ^ Bell, Peter M. (1980). "NOAA-B satellite mission unsuccessful". Eos. 61 (27): 515. Bibcode:1980EOSTr..61R.515B. doi:10.1029/eo061i027p00515-03. Retrieved 2 September 2014.[permanent dead link]
- ^ "AVHRR/2 1981-059A". NASA. 14 May 2020. Retrieved 31 December 2020. This article incorporates text from this source, which is in the public domain.
- ^ "TOVS 1981-059A". NASA. 14 May 2020. Retrieved 31 December 2020. This article incorporates text from this source, which is in the public domain.
- ^ "DCPLS 1981-059A". NASA. 14 May 2020. Retrieved 31 December 2020. This article incorporates text from this source, which is in the public domain.
- ^ "SEM 1981-059A". NASA. 14 May 2020. Retrieved 31 December 2020. This article incorporates text from this source, which is in the public domain.
- ^ "The NOAA Series". NASA GSFC. Archived from the original on 15 February 2013. Retrieved 8 December 2013. This article incorporates text from this source, which is in the public domain.
- ^ "The Orbital Debris Quarterly News" (PDF). NASA Johnson Space Center. Archived from the original (PDF) on 28 July 2004. Retrieved 27 August 2014. This article incorporates text from this source, which is in the public domain.
- ^ "NOAA 7 Satellite details 1981-059A NORAD 12553". N2YO. 8 December 2013. Retrieved 8 December 2013.