Weather Satellites: TIROS III

TIROS III - Television Infrared Observation Satellite III

Launch date: July 12, 1961

Launch site: Cape Canaveral, Florida

Launch vehicle: Three-stage Delta

PROGRAM OBJECTIVE:

Continued development of the experimental television techniques and infrared equipment leading to a world-wide meteorological information system. To obtain infrared measurements of the solar energy absorbed, reflected and emitted by the earth.

SPACECRAFT DESCRIPTION:

The spacecraft was 42 inches in diameter, 19 inches high and weighed 285 pounds. The craft was made of aluminum alloy and stainless steel then covered by 9260 solar cells. The solar cells served to charge the nickel-cadmium batteries.

Three major changes were made from the previous TIROS models. Two wide angle television cameras were housed in the craft in place of one high resolution and one low resolution camera. A new infrared experiment and improved remote control programmers were also new additions. This craft contained an electronic clock to control the operations of the infrared horizon sensor as well as the magnetic orientation system. A magnetic tape recorder was still provided for each camera to store photographs while the satellite was out of range of the ground station network. One scanning and two non-scanning radiometers were also on board. The antennas were of the same configuration as both previous TIROS models.

Although one of the cameras failed twelve days into the mission, photograph quality from the other camera was excellent and many tropical storms during the 1961 hurricane season were photographed. TIROS III was also credited with the discovery of Hurricane Esther. TIROS III was operational for 230 days.

PARTICIPANTS:

NASA, RCA, US Weather Bureau, Barnes Engineering