Launch date: May 17, 1974
Launch site: Cape Canaveral, Florida
Launch vehicle: Delta
The principle instrument on board was the Visible Infrared Spin Scan Radiometer (VISSR) which provided day and night imagery of cloud conditions over the full-disk. The satellite had the capability to continuously monitor cataclysmic weather events such as hurricanes and typhoons, relay meteorological data from over 10,000 surface locations into a central processing center for incorporation into numerical weather prediction models, and to perform facsimile transmission of processed images and weather maps to WEFAX field stations. In addition, a Space Environment Monitor (SEM) and Data Collection System (DCS) similar to those on the NOAA polar orbiters were installed.
SMS I was placed in a geostationary orbit directly over the equator at 45W (over the central Atlantic). This location provided continuous coverage of the Central and Eastern U.S. and out over the Atlantic Ocean. SMS I remained operational until deactivated by NASA on January 21, 1981.