The Echo I satellite.
You don't hear it so much any
more, "Live via satellite."
Satellite broadcasts have become too commonplace.
But broadcasting via satellite is a relatively recent advance.
Balloon technology helped us learn about how to use
satellites to send telecasts around the globe.
Radio communications are made
possible by the ionosphere,
which reflects radio waves. Weather conditions,
however, can cause the atmosphere and ionosphere
to absorb radio waves, preventing communication.
Today, communications are much
more reliable because
we have communications systems in place. But that wasn't
always the case. Back in 1960, there was no such thing
as a communications satellite. In fact, the first satellite
used to return communications was the moon in 1951.
The first voice returned from space was a recorded
Christmas message in 1958 by
President Dwight D. Eisenhower from an orbiting missile.
Improving on the idea of sending
and receiving signals from the moon, in 1960, NASA launched a balloon
satellite that would reflect communications signals. Echo I was a balloon made of aluminum-coated Mylar that was
launched by a rocket into space. When it reached orbit 1,000 miles (1,609
kilometers) above the Earth, it inflated from inside a 26.5-inch (67.3-centimeter)
magnesium sphere to 100 feet (30.48 meters) in diameter. Circling the
globe every two hours, it shone more brightly than the North Star in the
evening. The balloon captured the imagination of people who had watched
the first man-made object in space, the Russian satellite Sputnik 1, orbit the Earth in 1957.
reflected voice, music, pictorial, and teletype signals sent from ground
stations in the United States to receiving stations in Europe. Today's
communications satellites are active transceivers that receive a signal,
process it, and transmit it back to Earth. Echo I was called a passive satellite since
it simply reflected the signals. For eight years it orbited the Earth
being bombarded by micrometeorites and space dust until finally, its skin
gradually leaking gas, Echo I
fell back to Earth in 1968.
The balloon satellites, Echo I and the subsequent Echo II, provided information on how radiation
and solar particles heat up the atmosphere and the properties of transmitting
signals through the atmosphere. They helped pave the way for today's worldwide
communications and navigation satellite systems.
Gatland, Kenneth. The Illustrated Encyclopedia of Space Technology.
New York, NY: Crown Publishers, Inc. 1989.
Kirschner, Edwin J. Aerospace Balloons – From Montgolfiere to Space.
Fallbrook, Calif.: Aero Publishers, Inc. 1985.
Testing the Echo I satellite before its 1960 launch.