One of the earliest Earth-observing satellites, Seasat was designed to test various oceanographic sensors and gain a better understanding of Earth's seas.

Seasat operated in Earth orbit for 105 days, measuring sea-surface winds and temperatures, wave heights, atmospheric liquid water content, sea ice features and ocean topography, before a massive short circuit in the spacecraft's electrical system ended the mission on October 10, 1978.

Scientific Instrument(s)

- Radar altimeter
- Synthetic Aperture Radar (SAR)
- SEASAT-A Satellite Scatterometer (SASS)
- Visible and Infrared Radiometer (VIRR)
- Scanning Multichannel Microwave Radiometer (SMMR)