Since humans first looked into the night sky and wondered about the stars that they saw, they have dreamed of reaching outer space. The development of rockets in the latter part of the 20th century made it possible for governments to launch machines and eventually people into orbit and beyond. Governments’ goals for space exploration have been many and varied: to increase knowledge, to enhance national prestige and power, to contribute to military and economic strength, to provide a sense of wonder, to benefit the public through science, and to explore other planets and the Sun itself.
Many different kinds of space exploration are conducted, but the most important are those that involve sending unmanned or human missions to visit and study remote celestial bodies and their environments. This is a primary focus of national governments, which have largely funded most major space projects to date, from the launch of the first artificial satellite in 1957 (Sputnik 1) to the landings on the Moon by Apollo astronauts between 1968 and 1972.
Other planets, such as Mars and Venus, have also been visited by unmanned spacecraft, while other probes have traveled throughout the Solar System and into the Sun’s heliosphere—more than 100 times Earth’s distance away from the Sun.
The well-known list of benefits that accrue to society from space exploration includes advances in science and technology, such as electronic miniaturization, which contributes to medical equipment and manufacturing processes on Earth. Less well-known but equally significant are benefits that occur on a global scale as the world’s nations cooperate in space.