First weather satellite, TIROS I, launched 48 years ago

William Atkins
Tuesday, 01 April 2008 20:52

Science - Space

TIROS-I could see as far north and south as 55 degrees latitude; that is, about as far north as such places of Montreal Canada; Le Havre, France; and northern Manchuria, and as far south as Santa Cruz, Argentina; South Africa; and New Zealand.

In all, it sent back to scientists on Earth 22,952 images over its operational lifetime of 78 days.

It was able to send back TV pictures because it contained two black-and-white television cameras inside its structure of length 19 inches (48-centimeters) and diameter 42 inches (110 centimeters).

It also contained two magnetic tape recorders that stored the images when the satellite was out of communications with ground controllers. The 270-pound satellite was powered by internal nickel-cadmium batteries that were charged with 9,200 solar cells mounted on the body of the satellite.

The first television image sent back to Earth is found at: NASA First Picture from TIROS-I.

Even though the first satellite were called Television “Infrared” Observation Satellite, it did not contain the capability to take pictures in the "infrared" range of the electromagnetic (EM) spectrum. That capability was introduced in later satellites within the series.

Thus, TIROS-I could only take pictures during times when the sun was visible in its orbits, in the visible light range of the EM spectrum.

Eventually the later TIROS satellites (there was ten in all) carried infrared capabilities so images could be taken throughout its orbit, during night-time and daylight periods. The infrared capability allowed the camera to take a picture of an area about five to six miles (eight to ten kilometers) across.

The degree of contrast consisted of 256 different shades of gray, where each different degree indicated a different temperature: white indicated cold, on one end, and black represented hot, on the other end.

Previous to TIROS-I, weather forecasters, or meteorologists, could only predict the weather on Earth with the use of instruments aboard airplanes, balloons, and ships, along with devices stationed on the ground. They could measure wind speed and direction, temperature of the atmosphere, and rainfall amounts. Predictions were only fairly accurate for a few days into the future.

However, the first weather satellite, TIROS-I, allowed for future weather satellites to be launched. And, then scientists began to be able to monitor hurricanes and severe weather patterns. Warnings could be issued when bad weather was approaching sensitive coastal areas.

In addition, scientists could use weather satellites to monitor crops to find out if they were getting too much moisture, or not enough; and to even measure movements of mosquitoes across land masses. A multitude of measurements can not be taken of Earth's atmosphere, and the weather within it.

TIROS-II was launched on November 23, 1960. Eight more TIROS satellites eventually were launched over the next five years. More complex satellites eventually replaced TIROS, but not before history was made in bettering humankind.

TIROS-I pioneered a new era in weather science and global weather forecasting. In the end, the TIROS series of weather satellites proved invaluable to humankind. It showed that weather forecasting from space is not just possible but very effective.

We all should remember TIROS-I and the dedicated team that designed, developed, and operated the satellite. For without them, our current global weather forecasting system would not be protecting us from dangerous weather patterns and storms, providing accurate measurements for growing crops, and many other valuable uses here on Earth.

For additional information on the historic TIROS-I satellite, please read “TIROS I: First Eye in the Sky.”