Introduction

As a huge plume of white gas rushes beneath an enormous pillar, the ground nearby begins to rumble. The sound of the blast intensifies and then suddenly, as mission control holds its breath, the rocket clears the tower and shoots swiftly away from the earth.

Such was the scene on March 10, 2003 when a Delta 4 Launch Vehicle perfectly placed another satellite into orbit. This particular payload was a Defense Satellite Communications System spacecraft for the Pentagon (Covault 54). Thousands of these technological wonders now circle the Earth, relaying data so we can enjoy an evening of Monday night football, navigate from our cars, and conduct advanced research not possible in a terrestrial environment.

Early Satellites

In 1657, Cyrano de Bergerac's Voyage to the Moon and, in 1865, Jules Verne's From the Earth to the Moon sparked imaginary expeditions at the edges of human thought. These science fiction writers envisioned a future where machines took explorers out of this world. One of the first steps toward such a future was made in 1957 when the USSR launched Sputnik.

Sputnik

Sputnik was the world's first artificial satellite. Launched on October 4, 1957, the basketball sized orbiter weighed 183 lbs and orbited the earth every ninety minutes at an altitude of 230 km above sea level. Its only scientific equipment was a radio transmitter that let people detect its presence in space. The scientific community was completely in awe as the tiny craft made its way around the world in less than two hours (Sputnik). Soon afterward, the USSR launched another satellite, which it called Sputnik II. To challenge the superiority of the Russian Space Agency, the United States countered with its own satellite, Explorer I.

Explorer I

Launched on January 31st, 1958, Explorer I was the first project of NASA, the National Aeronautics and Space Administration. The spacecraft had a total length of only 80 inches with a weight of 30 lbs. Its sophisticated sensors allowed for the discovery of the magnetic radiation belts around the world. These belts, known today as the Van Allen belts, act as a shield to help protect the earth from harmful space radiation.

Soon after this early success, NASA began a series of new projects aimed at exploring beyond the earth. The program was called Mariner.

Mariner II

Although both the United States and the USSR had demonstrated the ability to launch satellites into space, neither nation had ventured beyond the Earth's orbit. This all changed in 1962 when NASA launched the Mariner II spacecraft. Using onboard rockets, the 200kg vehicle shot out of Earth's gravitational field and became the first spacecraft to fly past another planet. It carried six scientific instruments and took nearly two months to reach Venus, whose geology it studied from orbit (Mariner). The mission was nearly cut short, however, when one of Mariner II's solar panels was damaged and stopped supplying power to the onboard systems. Fortunately, the remaining panel was able to supply power for the entire spacecraft and allowed for the continuation of the mission.