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TIROS I (or TIROS-1) was the first successful low-Earth orbital weather satellite, and the first of a series of Television Infrared Observation Satellites.

Tiros 1
Tiros satellite navitar.jpg
Tiros I prototype on display at the Smithsonian National Air and Space Museum.
Mission typeWeather satellite
Harvard designation1960 β 2
COSPAR ID1960-002B
SATCAT no.29
Mission duration78 days
Spacecraft properties
Spacecraft typeTIROS
ManufacturerRCA Astro
Launch mass122.5 kilograms (270 lb)[2]
Start of mission
Launch dateApril 1, 1960, 11:40:09 (1960-04-01UTC11:40:09Z) UTC[3]
RocketThor DM-18 Able II
Launch siteCape Canaveral LC-17A
End of mission
Last contactJune 15, 1960 (1960-06-16)
Orbital parameters
Reference systemGeocentric
Semi-major axis7,026.96 kilometers (4,366.35 mi)[4]
Perigee altitude631 kilometers (392 mi)
Apogee altitude665 kilometers (413 mi)
Period98.76 minutes
RAAN264.3671 degrees
Argument of perigee226.1327 degrees
Mean anomaly133.7550 degrees
Mean motion14.74045109
EpochApril 22, 2016, 21:05:55 UTC
two slow-scan visible television camera
(wide-angle and narrow-angle)
horizon sensor
sun angle sensor
← None



Instruments and equipment of TIROS-1.

The TIROS-1 spacecraft was launched by NASA and partners at 6:40 AM EST[5] on April 1, 1960, from Cape Canaveral, Florida, in the United States. Mission partners were NASA, the U.S. Army Signal Research and Development Laboratory, RCA, the U.S. Weather Bureau, and the U.S. Naval Photographic Interpretation Center.[1]


First TV image of Earth from space was recorded by TIROS-1[6]

The TIROS Program was NASA's first experimental step to determine if satellites could be useful in the study of the Earth. At that time, the effectiveness of satellite observations was still unproven. Since satellites were a new technology, the TIROS Program also tested various design issues for spacecraft: instruments, data and operational parameters. The goal was to improve satellite applications for Earth-bound decisions, such as "should we evacuate the coast because of the hurricane?".[1]

The TIROS Program's first priority was the development of a meteorological satellite information system. Weather forecasting was deemed the most promising application of space-based observations.[1]

TIROS proved extremely successful, providing the first accurate weather forecasts based on data gathered from space. TIROS began continuous coverage of the Earth's weather in 1962, and was used by meteorologists worldwide. The program's success with many instrument types and orbital configurations led to the development of more sophisticated meteorological observation satellites.[1]


The two cameras for TIROS-1 were for the visible spectrum. The cameras were slow-scan, taking a half-second to record an image, but had a 1.5 millisecond shutter. One camera had a wide-angle lens (104 degrees/~750 miles) with the other having a narrow-angle (12.67 degrees/~65 miles) with corresponding image resolutions of 1.5 miles and 1000 feet. Also included were a horizon sensor and a sun sensor, both used for indicating the orientation of the satellite for the images.

TIROS-1 Magnetic Tape Data Recorder


  1. ^ a b c d e "TIROS". NASA Science. Retrieved December 8, 2013.
  2. ^ "TIROS 1". National Space Science Data Center. Retrieved December 8, 2013.
  3. ^ McDowell, Jonathan. "Launch Log". Jonathan's Space Page. Retrieved December 8, 2013.
  4. ^ "TIROS 1 Satellite details 1960-002B NORAD 29". N2YO. December 7, 2013. Retrieved December 8, 2013.
  5. ^ "U.S. Launches Camera Weather Satellite". The Fresno Bee. AP and UPI. April 1, 1960. pp. 1a, 4a.
  6. ^ Anderson, George D. (April 1, 2010). "The first weather satellite picture". Weather. 65 (4): 87. Bibcode:2010Wthr...65...87A. doi:10.1002/wea.550. ISSN 1477-8696.

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