Space Exploration

The space age began with the launch of the first artificial satellites in 1957. A human first went into space in 1961. Since then, astronauts have ventured into space for ever greater lengths of time, even living aboard orbiting space stations for more than a year. Two dozen people have circled the Moon or walked on its surface.

Space exploration became possible at the height of the Cold War, and superpower competition between the United States and the USSR gave a boost to space programs in both nations. Indeed, the primary impact of Sputnik was political in the United States Sputnik triggered nationwide concern about Soviet technological prowess. When the USSR succeeded in putting the first human into space, it only added to the disappointment and shame felt by many Americans, and especially by President Kennedy. Against this background, Alan Shepard's Mercury flight on May 5, 1961, was a welcome cause for celebration. This was the genesis of the Apollo program. Although there were other motivations for going to the Moon scientific exploration among them Cold War geopolitics was the main push behind the Moon race. Cold War competition also affected the unpiloted space programs of the United States and USSR.

The first challenge of space exploration was developing rockets powerful enough and reliable enough to boost a satellite into orbit. These boosters needed more than brute force, however; they also needed guidance systems to steer them on the proper flight paths to reach their desired orbits. The next challenge was building the satellites themselves. The satellites needed electronic components that were lightweight, yet durable enough to withstand the acceleration and vibration of launch. Creating these components required the world's aerospace engineering facilities to adopt new standards of reliability in manufacturing and testing. On Earth, engineers also had to build tracking stations to maintain radio communications with these artificial "moons" as they circled the planet.

Beginning in the early 1960s, humans launched probes to explore other planets. The distances traveled by these robotic space travelers required travel times measured in months or years. These spacecraft had