Transmits the first pictures of the cloud cover
First spin-stabilized satellite
Mass at launch
0.48 long, 1.07 dia
TIROS I satellite on test stand during preliminary test stage.
TIROS satellite mated to rocket for launching.
TIROS I was the world's first weather satellite to test the experimental television techniques leading to a
world-wide meteorological satellite information system. It also was the first satellite to test sun angle and horizon
sensor systems for spacecraft orientation. The main objective of the TIROS program was to demonstrate the feasibility
and capability of observing the Earth's cloud cover and weather patterns from space. Although the program was
experimental, this first space-borne system demonstrated the capability to acquire information which meteorologists
could use immediately in an operational setting.
TIROS I was operational for only 78 days and proved that satellites could be a useful tool for surveying global weather conditions from space
The spacecraft was 107 cm in diameter, 48 cm high and weighed 112,5. kg. The craft was made of aluminum alloy and
stainless steel covered by 9200 solar cells. The solar cells served to charge the nickel-cadmium (nicad) batteries.
Three pairs of solid-propellant spin rockets were mounted on the base plate. Two television cameras were housed in the
craft, one low resolution and one high resolution. A magnetic tape recorder for each camera was supplied for storing
photographs while the satellite was out of range of the ground station network. The antennas consisted of four rods
from the base plate to serve as transmitters and one vertical rod from the center of the top plate to serve as a
receiver. The craft was spin-stabilized and space oriented (not Earth-oriented). Therefore, the cameras were only
operated while they were pointing at the Earth when that portion of the Earth was in sunlight. The video systems
relayed thousands of pictures containing cloud-cover views of the Earth. Early photographs provided information
concerning the structure of large-scale cloud regimes..
"For the first time, man had a complete look at the weather over a large segment of the Earth’s surface," said
Chief of the U.S. Weather Bureau. He also reports that getting the same information contained in the cloud structure
photographs taken by the Tiros I would have required thousands of weather ships over the Pacific.