Television InfraRed Observation Satellite
TIROS 6 satellite
ManufacturerRCA Astrospace
Lockheed Martin
Country of originUnited States
RegimeLow Earth orbit
First TV image of Earth from space

Television InfraRed Observation Satellite (TIROS) is a series of early weather satellites launched by the United States, beginning with TIROS-1 in 1960. TIROS was the first satellite that was capable of remote sensing of the Earth, enabling scientists to view the Earth from a new perspective: space.[1] The program, promoted by Harry Wexler, proved the usefulness of satellite weather observation, at a time when military reconnaissance satellites were secretly in development or use. TIROS demonstrated at that time that "the key to genius is often simplicity".[2] TIROS is an acronym of "Television InfraRed Observation Satellite" and is also the plural of "tiro" which means "a young soldier, a beginner".[3]

The Advanced Research Projects Agency (now DARPA) initiated the TIROS program in 1958 and transferred the program to the National Aeronautics and Space Administration (NASA) in 1959.[4] Participants in the TIROS program also included, United States Army Signal Research and Development Laboratory, Radio Corporation of America (RCA), the United States Weather Bureau Service, the United States Naval Photographic Interpretation Center (NPIC), the Environmental Science Services Administration (ESSA), and the National Oceanic and Atmospheric Administration (NOAA).[5]


William G. Stroud displaying TIROS-I's circuitry to Lyndon B. Johnson on 4 April 1960.

The 122 kg (269 lb) satellite was launched into a nearly circular low Earth orbit by a Thor-Able rocket. Drum-shaped with a 42-inch (110 cm) diameter, and height of 19 inches (48 cm), the TIROS satellite carried two 6-inch (15 cm) long television cameras. One of the cameras had a wide-angle lens with an f/1.6 aperture that could view an 800-mile-wide area of the Earth. The other camera had a telephoto lens with an f/1.8 aperture and 10- to 12-power magnification[citation needed] compared to the wide angle camera.

The satellite itself was stabilized in its orbit by spinning like a gyroscope. When it first separated from the rocket's third stage, it was spinning at about 136 revolutions per minute (rpm). To take unblurred photographs, a de-spin mechanism slowed the satellite down to 12 rpm after the orbit was achieved.

The camera shutters made possible the series of still pictures that were stored and transmitted back to earth via 2-watt FM transmitters as the satellite approached one of its ground command points. After transmission, the tape was erased or cleaned and readied for more recording.


Diagram showing progression of meteorological satellites from TIROS I to TIROS-N

TIROS continued as the more advanced TIROS Operational System (TOS),[6] and eventually was succeeded by the Improved TIROS Operational System (ITOS) or TIROS-M,[7] and then by the TIROS-N[8] and Advanced TIROS-N[9] series of satellites. NOAA-N Prime (NOAA-19) is the last in the TIROS series of NOAA satellites that observe Earth's weather and the environment.[10]

The naming of the satellites can become confusing because some of them use the same name as the over-seeing organization, such as "ESSA" for TOS satellites overseen by the Environmental Science Services Administration (for example, ESSA-1) and "NOAA" (for example, NOAA-M) for later TIROS-series satellites overseen by the National Oceanic and Atmospheric Administration.[10]

As of June 2009, all TIROS satellites launched between 1960 and 1965 (with the exception of TIROS-7) were still in orbit.[11]

TIROS Operational System



Graphic of the operational life of various satellites of the TIROS-N design

Advanced TIROS-N

The Advanced TIROS-N (ATN) spacecraft were similar to the NOAA-A through -D satellites, apart from an enlarged Equipment Support Module to allow integration of additional payloads. A change from the TIROS-N through NOAA-D spacecraft was that spare word locations in the low bit rate data system TIROS Information Processor (TIP) was used for special instruments such as the Earth Radiation Budget Satellite (ERBE) and SBUV/2. The search and rescue (SAR) system became independent, utilizing a special frequency for transmission of data to the ground.[23]


  1. ^ Space-Based Remote Sensing of the Earth: A Report to the Congress. NASA Technical Reports Server (Report). September 1987. hdl:2060/19880008662. Public Domain This article incorporates text from this source, which is in the public domain.
  2. ^ "Modern Mechanix: How Tiros Photographs the World". Archived from the original on 18 September 2007. Retrieved 3 November 2007.
  3. ^ "tiro - Wiktionary". Retrieved 19 April 2017.
  4. ^ "Feb. 7, 1958: U.S. Creates ARPA in Response to Sputnik". 6 February 2008. Archived from the original on 17 May 2024. Retrieved 17 May 2024.
  5. ^ EXPLORES! (EXPloring and Learning the Operations and Resources of Environmental Satellites!) Archived 1997-07-24 at the Wayback Machine
  6. ^ "WMO OSCAR | Details for Satellite Programme: TOS". Retrieved 20 March 2024.
  7. ^ "WMO OSCAR | Details for Satellite Programme: NOAA 3rd generation / ITOS". Retrieved 20 March 2024.
  8. ^ "WMO OSCAR | Details for Satellite Programme: NOAA 4th generation". Retrieved 20 March 2024.
  9. ^ "WMO OSCAR | Details for Satellite Programme: NOAA 4th generation / POES". Retrieved 20 March 2024.
  10. ^ a b c d e "NOAA-N Prime" (PDF). NP-2008-10-056-GSFC. NOAA. 16 December 2008. Archived from the original (PDF) on 16 February 2013. Retrieved 8 October 2010. Public Domain This article incorporates text from this source, which is in the public domain.
  11. ^ "U.S. Space Objects Registry". Bureau of Oceans and International Environmental and Scientific Affairs. Archived from the original on 21 May 2009. Retrieved 25 June 2009. Public Domain This article incorporates text from this source, which is in the public domain.
  12. ^ "WMO OSCAR | Satellite: ESSA-1". Retrieved 20 March 2024.
  13. ^ "WMO OSCAR | Satellite: ESSA-2". Retrieved 20 March 2024.
  14. ^ "WMO OSCAR | Satellite: ESSA-3". Retrieved 20 March 2024.
  15. ^ "WMO OSCAR | Satellite: ESSA-4". Retrieved 20 March 2024.
  16. ^ "WMO OSCAR | Satellite: ESSA-5". Retrieved 20 March 2024.
  17. ^ "WMO OSCAR | Satellite: ESSA-6". Retrieved 20 March 2024.
  18. ^ "WMO OSCAR | Satellite: ESSA-7". Retrieved 20 March 2024.
  19. ^ "WMO OSCAR | Satellite: ESSA-8". Retrieved 20 March 2024.
  20. ^ "WMO OSCAR | Satellite: ESSA-9". Retrieved 20 March 2024.
  21. ^ a b c d e f g h "History of NOAA's environmental satellites". Spaceflight Now. 22 June 2002. Retrieved 7 June 2015.
  22. ^ a b c d e NOAA-K (PDF) (Booklet), Greenbelt, Maryland: NASA Goddard Space Flight Center, 1998, p. 20, NP-1997-12-052-GSFC, retrieved 12 June 2015
  23. ^ Kidwell, Katherine B., ed. (November 1998). NOAA Polar Orbiter Data User's Guide (PDF). National Climatic Data Center, Asheville, NC: National Oceanic and Atmospheric Administration. sec. 1.1. Retrieved 14 June 2015.
  24. ^ a b c "POES Decommissioned Satellites". Office of Satellite and Product Operations. NOAA. 30 September 2014. Retrieved 5 June 2015.
  25. ^ a b c "POES Operational Status". Office of Satellite and Product Operations. NOAA. Retrieved 5 June 2015.
  26. ^ a b "NOAA retires NOAA-16 polar satellite". NOAA News Archive. 9 June 2014. Retrieved 7 June 2015. NOAA exclusively operates afternoon polar orbit spacecraft, while its key international partner, the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT), flies mid-morning orbit spacecraft.
  27. ^ Justin Ray (6 February 2009). "History Abounds in Launch of Crucial Weather Satellite". Spaceflight Now. Retrieved 25 October 2010. A last-of-its-kind weather observatory...
  28. ^ Harrod, Emily D. (28 May 2009). "PSB - All POES, All Instruments, Switch to NOAA-19 as Operational Afternoon Satellite, 2 June 2009". Office of Satellite and Product Operations. NOAA. Retrieved 7 June 2015.