Weather Satellites: ATS I

ATS I - Applications Technology Satellite I

Launch date: December 7, 1966

Launch site: Cape Canaveral, Florida

Launch vehicle: Atlas Agena D

PROGRAM OBJECTIVE:

To test the experimental geostationary techniques of satellite orbit and motion, measure the orbital environment at 23,000 miles above the earth's surface, and to transmit meteorological information (imagery and data) to surface ground stations.

SPACECRAFT DESCRIPTION:

The spacecraft was a cylinder 56 inches in diameter, 57 inches high and weighed 750 pounds. A phased array of eight whip antennas extended from the top, and a phased array of eight VHF antennas extended from the base. The sides of the cylinder were covered by 23,870 solar cells which, along with nicad batteries, provided the power for the craft. Two meteorological experiments were on board. One was a spin scan cloud camera which provided continuous, full-disk hemispheric images of the sun-lit Earth every half hour. The spinning motion of the satellite generated line scans with a spatial resolution of 3.2 kilometers. This process took approximately twenty minutes for the full image, and then ten minutes to reset the camera for a new image. The second experiment was Weather Facsimile (WEFAX), a data relay and re-transmission instrument. This instrument relayed data from the central ESSA data processing facility to APT ground stations located around the western hemisphere.

ATS I was placed in a transfer orbit directly over the equator over Ecuador. The transfer orbit meant that the satellite would drift slowly westward with time. The satellite eventually reached 151 degrees west (just east of Christmas Island) where it was deactivated on December 1, 1978. Of the satelliteÕs twelve year life span, useful data was received for the first six (1966-1972).

PARTICIPANTS:

NASA, Hughes, Jet Propulsion Laboratory, Aerospace Corporation, Bell Telephone