Status: Retired 1972. First Launch: 1972-07-23. Last Launch: 1972-12-11. Number: 2 . Payload: 1,300 kg (2,800 lb). Thrust: 2,500.00 kN (562,000 lbf). Gross mass: 116,500 kg (256,800 lb). Height: 34.00 m (111.00 ft). Diameter: 2.44 m (8.00 ft). Apogee: 1,500 km (900 mi).
LEO Payload: 1,300 kg (2,800 lb).
The first Long Tank Thrust Augmented Thor/Delta to be launched from Vandenberg AFB using nine solid rocket motors successfully placed the Environmental Resources Technology Satellite (ERTS-A) in orbit. Earth Resources Technology Satellite. Spacecraft engaged in practical applications and uses of space technology such as weather or communication (US Cat C).
Environmental research. Primary experiments included a temperature-humidity infrared radiometer (THIR) for measuring day and night surface and cloudtop temperatures as well as the water vapor content of the upper atmosphere, electrically scanning microwave radiometer (ESMR) for mapping the microwave radiation from the earth's surface and atmosphere, infrared temperature profile radiometer (ITPR) for obtaining vertical profiles of temperature and moisture, Nimbus E microwave spectrometer (NEMS) for determining tropospheric temperature profiles, atmospheric water vapor abundances, and cloud liquid water contents, selective chopper radiometer (SCR) for observing the global temperature structure of the atmosphere, and a surface composition mapping radiometer (SCMR) for measuring the differences in the thermal emission characteristics of the earth's surface.