Weather Satellites: SMS II

SMS II - Synchronous Meteorological Satellite II

Launch date: February 6, 1975

Launch site: Cape Canaveral, Florida

Launch vehicle: Delta

PROGRAM OBJECTIVE:

The second operational satellite designed to sense meteorological conditions from a fixed location above the Earth, and to provide this data to operational forecasters and private interests on the ground. The satellite was designed to compliment SMS I and cover the Western U.S. and Pacific basin.

SPACECRAFT DESCRIPTION:

The spacecraft was a cylinder 75 inches in diameter, 103 inches high and weighed 630 pounds. The sides of the cylinder were covered by 15,000 solar cells which, along with nicad batteries, provided the power for the craft. A single triangular magnetometer unit was located on the top of the craft which extended 33". The spacecraft was spin stabilized and rotated at 100 revolutions per minute.

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 II was placed in a geostationary orbit directly over the equator at 135W (over the east-central Pacific) where it remained operational until deactivated by NASA on August 5, 1982.

PARTICIPANTS:

NASA, NOAA, Philco-Ford, McDonnell Douglas