The August 12, 1960, launch of the Echo 1A was the first successful one for NASA in its communications satellite program, almost three years after the launch of Russia's Sputnik and two and a half years after the U.S. put its very first satellite, the Explorer 1, into orbit. Not long thereafter, according to the space agency, Echo allowed President Eisenhower to make the first voice communication via satellite.
This image shows the original Echo 1 balloon being inflated in 1958; its launch attempt in May 1960 was not successful. The Echo 1A now is commonly referred to as Echo 1.
The Mylar polyester film was just 0.5 mil (0.0127 mm) thick. With its highly reflective surface, the Echo 1 was said to be easy to spot from the ground with the naked eye.
NASA offers this additional technical information about Echo:
"It had 107.9-MHz beacon transmitters for telemetry purposes. These transmitters were powered by five nickel-cadmium batteries that were charged by 70 solar cells mounted on the balloon. Because of the large area-to-mass ratio of the spacecraft, data for the calculation of atmospheric density and solar pressure could be acquired."
Echo 1 had a mass of 180 kilograms.
Echo 1 went out of service when its orbit deteriorated and it re-entered the atmosphere in May 1968. A second balloon, the somewhat larger Echo 2, was in service from January 1964 to June 1969.
Although NASA's work with passive satellites in the Echo program gave way to projects involving active technology, the space agency isn't done working with balloons. For a look at more contemporary efforts involving balloons, see "Wallops Flight Facility, NASA's hidden launch shop."