Voyager: How have satellites improved in the last 50 years?

Answer: As you probably know, the first artificial satellite to orbit the earth was Sputnik, launched by the Soviet Union in October 1958.  I was 5 years old then and remember the excitement of going outside after sunset and looking for the satellite passing overhead out in space.

Satellites were first launched during the Cold War, a period of tension, distrust and competition between the United States and the Soviet Union.  There was a looming threat the countries would launch nuclear weapons against each other if things got really bad. The United States and the Soviet Union developed satellites to spy on each other.

Initially pictures were recorded on film and sent back to Earth in a capsule with a parachute, which was then snatched in midair by an Air Force plane.  There were only two film canisters per spacecraft so the spies had to be very selective about what was photographed.

About a decade later, President Lyndon Johnson publicly recognized that satellites could do so much more. “We’ve spent 35 or 40 billion dollars on the space program,” Johnson said in 1967,  “And if nothing else had come out of it except the knowledge we gained from space photography, it would be worth 10 times what the whole programs cost.”

In the 1970s, new technology helped us see the earth even better. NASA’s Landsat program beamed back spectacular, high-resolution images of the planet that helped scientists manage crops better, detect fault lines, and track weather events such as droughts, forest fires, and ice floes.

-- Dr. David Sandwell, geophysics professor, Cecil H. and Ida M. Green Institute of Geophysics and Planetary Physics