The exploration of space is one of mankind’s most fascinating ventures. It has carried first instruments, then people themselves, beyond Earth’s atmosphere into a remoteness that until recently was barely known or understood. These journeys were the climax of centuries of speculation and study and decades of practical problems that had to be solved.
Space exploration is also a source of pride and prestige for nations, regions, and individuals. It may be that this explains why professional astronauts and laypeople alike are willing to sit at their peril, in the words of Tom Wolfe’s The Right Stuff (1979), on top of enormous Roman candles like Redstone, Atlas, Titan or Saturn rockets, while mechanical stand-ins take them into orbit and toward the Moon and other planets within our Solar System.
National agencies sponsor a variety of programs to develop and operate spacecraft. Many of these are grouped into “program families” such as Explorer, Apollo and Voyager in the United States; Venera and Salyut in Russia; and SPOT and Meteosat in Europe. They include satellites that are used for a variety of purposes including navigation, communications, weather, and research. They may be unmanned, as in the case of probes sent to fly by or crash on a lunar or planetary surface, or crewed, as in the case of space shuttles and other vehicles that have flown human beings into outer space and back. Some are reusable, such as the space shuttle, which can be refueled and reenter Earth’s atmosphere after each flight.