In 1957, Sputnik I pierced the atmosphere, shocked the world, and started a space race that launched the greatest engineering team effort in American history. The resulting space program re-ignited the pioneering spirit that had once driven humans to explore every corner of the Earth, and set a new course for discovery in a long-dreamed of realm -- outer space.
Along the way, the space program has greatly expanded the world's knowledge base. As the average person learned more about the universe and planet Earth, engineers advanced technologies in the areas of energy, communications, materials, structures, and computers - all the systems that made space travel possible. In the process, their work has spawned more than 60,000 products that have had a direct impact on the general public, with more products sure to come.
The technical challenges faced to build, launch, and guide spacecraft were staggering. Most of the technology developed was entirely new. Early human space flight leading up to the Apollo program required the integration of numerous technologies on a scale never before undertaken. Every major technological field was tapped. The launch and return of spacecraft, from Apollo to the Shuttle, is one of the monumental engineering triumphs in all of human history.
The need to have computers that would fit on board a spacecraft drove the development of the electronics industry. Advances enabled the development of microcomputers, small in size but great in calculation and communications capabilities, which eventually led to the burgeoning PC industry. In the biomedical field, tests on the rigors of space on astronauts provided insight into aging. Sensors that allowed doctors to monitor the astronauts' health were soon used routinely throughout the medical profession. Plastics and polymers developed for use in space had thousands of applications on Earth. As engineers learned to transport volatile fluids and gases in space, they applied this knowledge to sea and ground transportation of similar materials.
Because a huge amount of energy is required for spacecraft to escape the Earth's atmosphere, most of the weight of a launch vehicle at liftoff is fuel. Engineers have devised complex systems of pipework and turbopumps that force huge volumes of liquid fuel (often hydrogen) into the combustion chamber inside the rocket, where the fuel is mixed with pure oxygen. This action results in a violent combustion (explosion) that produces very hot waste gases. These gases are forced backward at high speeds out of the rocket nozzle, producing a reaction force that pushes the launcher upward. A second stage then fires to propel the payload to its correct orbit.
The first spacecraft to be launched were Earth-orbiting satellites that began a revolution in global communications. Eventually they would provide instantaneous voice, data, and video services to hundreds of millions of people, and be instrumental in the areas of weather forecasting; national defense services; navigation for airplanes, automobiles, and ships; environmental and scientific research; and wireless communications systems.
A communications satellite races around the earth at almost 2 miles per second - 10 times as fast as a jet aircraft. Like any moving object, its tendency is to move in a straight line, in a path that would take it farther and farther away from the Earth. This tendency is countered by gravitational forces, which constantly accelerate the satellite back toward Earth. The stronger the gravitational force acting on a satellite, the faster it must fly to avoid spiraling down. Engineering plays a role in the success of its journey, from materials and structure to the rockets and boosters that elevate it to the proper orbit.
In the late 1950s, engineering advances with liquid hydrogen led to the RL-10 rocket engine. Since 1963, it has launched an array of America's most sophisticated unpiloted spacecraft, including Viking, Mariner, and Pioneer, without a single engine failure. The RL-10 led to the development of larger hydrogen-fueled engines that made the lunar landing possible.
Wernher von Braun and his team played a crucial role in the U.S. space program by outlining the basic technology that would achieve the first major space goal: the moon landing. The engineering challenges included building a service module containing fuel, power, and life-support systems; a command module; and a lunar-landing vehicle; as well as developing the fuel and the engine to boost the 40-ton ship into orbit. Von Braun devised the most powerful rocket ever built, the giant Saturn V. It was over 360 feet long and weighed 3,000 tons. Its lift-off engines delivered an incredible 7.5 million pounds of thrust and burned more than 10 tons of fuel each second.
Milestones that led to the moon landing included the Mercury program, 1961-63, with Col. John Glenn's historic first flight which took him around the Earth three times and proved the capsule's material and structure could withstand the enormous temperatures of re-entry. The space docking between two Gemini spacecraft in 1965 was another significant step towards the Apollo program because it solved the problem of the amounts of fuel needed to get to the moon. The actual moon landing in 1969 was an astounding achievement, both technologically and socially. Many people around the world gathered outside to watch President Nixon make the connection with the astronauts. As they watched on large screen televisions, they could also look up and see the moon - some 240,000 miles away. Surely an unforgettable experience.
During the 1970s the U.S. space program de-emphasized piloted flights and stressed instead fully automated missions that sent spacecraft close to the surfaces of Mercury, Mars, Jupiter, and Saturn. In 1982 the Soviets succeeded in landing an exploration craft on Venus, where it successfully transmitted pictures back to Earth.
In the 1980s the Space Shuttle program was launched, heralding a new era in aviation design and technology. The Shuttle, with its airplane shape and huge disposable booster rockets, is part aircraft, part rocket. Dozens of shuttle flights have conducted hundreds of scientific experiments and medical tests, and carried satellites and the Hubble telescope into space.
If Sputnik was the catalyst for the U.S. space program, President Kennedy was the inspiration when he said in 1962: "We have a long way to go in this space race. But this is the new ocean, and I believe the U.S. must sail on it and be second to none." Only seven years later, Neil Armstrong stepped onto the lunar landscape. As he declared the moment a "giant leap for mankind," back on Earth, a note was being placed on JFK's grave to honor his vision: "Mr. President, the Eagle has landed."
