The history of space exploration began near the turn of the twentieth century when scientists started using balloons to carry instruments to 100,000 feet (30,480 meters) to study cosmic rays. After World War II sounding rockets arcing up to 400,000 feet (121,920 meters) gave scientists a fleeting glimpse of the ultraviolet and X-ray radiation from the Sun and stars. Although this effort harvested a wealth of scientific data, space exploration received an immeasurable boost from the International Geophysical Year (IGY) of July 1957 to December 1958, a cooperative scientific endeavor to study solar-terrestrial relations during a period of maximum solar activity; in all, sixty-seven nations conducted cooperative experiments.
In 1955 both the former Soviet Union and the United States announced that as part of their contribution to the IGY, each would launch a scientific satellite into Earth orbit. Satellites provided months of observing time hundreds of miles above Earth's atmosphere, something neither balloons nor sounding rockets could do. This resulted in both the launch of the Soviet spacecraft Sputnik I on 4 October 1957 and the American Explorer 1 on 31 October 1958. This latter satellite discovered what came to be known as the Van Allen radiation belts.
The excitement and, indeed, fear of the Soviet success with Sputnik coming at the height of the Cold War touched off a space race between the two rival superpowers. The crisis led directly to several actions in the United States aimed at “catching up” to the Soviet Union's space achievements:
• Review and reorganization of all government civil and military space activities
• Establishment of a presidential science adviser at the White House
• Consolidation of several military space activities under centralized management
• Establishment of the National Aeronautics and Space Administration (NASA)
• Passage of the National Defense Education Act to provide educational resources
At first the world's activities in space exploration were limited to watching the two rivals “one up” each other. Although scientific pursuits rode atop their rockets, both the United States and the USSR expended the funds necessary to accomplish them to impress the remainder of the world. Beginning in 1958 the United States went head-to-head with the Soviets in a race to the Moon, making four unsuccessful attempts to send probes there. After several failures, in January 1959 the Soviets launched Luna 1 into orbit around the Sun, following up with Luna 3 to transmit pictures of the far side of the Moon. Eventually, the United States' Pioneer 5 finally flew past the Moon.
This success signaled the dawn of an aggressive effort to explore beyond Earth. The United States emphasized these efforts during its Cold War rivalry with the Soviets through 1990:
• Human spaceflight as it evolved in Mercury's single-astronaut program (1961–1963) to ascertain if a human could survive in space; Project Gemini (1965–1966) with two astronauts practicing for space operations; Project Apollo (1961–1972) to explore the Moon; and sustained operations in Earth orbit with the Space Shuttle (1981–present)
• Robotic missions to the Moon (Ranger, Surveyor, and Lunar Orbiter), Venus (Pioneer Venus), Mars (Mariner series, Viking 1 and 2, Pathfinder, Mars Global Surveyor, and others), and the outer planets (Pioneer 10 and 11, Voyager 1 and 2, Galileo, and Cassini)
• Orbiting space observatories (Orbiting Solar Observatory, Hubble Space Telescope, and Chandra) to view the galaxy from space without the clutter of Earth's atmosphere
• Remote-sensing Earth satellites (Landsat satellites for environmental monitoring and others)
• Applications satellites for communications and weather monitoring
• Skylab orbital workshop, followed by a true space station
The Soviet Union, engaged in its own efforts to send cosmonauts to the Moon, was unable to develop the large rocket necessary and quietly cancelled the program in favor of robotic exploration. For example, on 12 September 1970 it succeeded in returning to Earth lunar samples obtained by a robotic probe, Luna 16. In addition, on 10 November 1960 the Soviet Union launched a robotic probe to the Moon that carried Lunokhod 1—a small Moon rover that operated under remote control. The Soviets also launched their first space station, Salyut 1, on 19 April 1971 and maintained a succession of these in Earth orbit through the life of Mir, between 20 February 1986 and its de-orbiting in 2001.
Since the 1970s space exploration has taken on an increasingly international complexion. To some extent this resulted from the incorporation of scientific experiments from a range of international scholars into the U.S. and Soviet programs, but other nations also developed the technologies necessary to reach space. For instance, the European Space Agency (ESA), created in 1973, began developing its own capabilities and engaged in a succession of space science missions. These included a mission to Halley's Comet in the 1980s, an international solar-polar mission, and the stunningly successful Huygens probe (launched on Cassini in 1996) that in 2005 landed on Titan, a moon of Saturn. Japan, India, Canada, Brazil, Israel, and others also soon became involved in space exploration.
Many of these endeavors had a broad international component. The United States brought international partners into its scientific mission, including the Space Shuttle, which began flying in 1981. This included both flying non-U.S. astronauts and using a “Spacelab” science module built by the ESA. The Soviets followed an identical path, flying international cosmonauts on some of its space stations. The pinnacle of this was the International Space Station (ISS), begun in 1984 by the United States as a Cold War initiative to unite its allies behind a large space project. It incorporated Russia and several other nations into the ISS initiative in the post–Cold War era. The first element of the station reached orbit in 1998 and the first crew arrived in 2000. Steady construction continued until the loss of the Columbia shuttle and its crew, which included an Israeli astronaut, on 1 February 2003.
This effectively ended logistics support to the ISS by the United States, and the crew had to be reduced to two members to conserve the meager resources that could be brought to it by the small Russian vehicles. Meantime NASA worked to correct the causes of the Columbia accident. In January 2004 President George W. Bush announced a “Vision for Space Exploration” that refocused NASA on a return to the Moon. It required the retirement of the Space Shuttle by 2010, the investment of funding for that program in the development of a new space capsule and launch vehicle, known as the Constellation program, and the phasing out of the ISS as a major U.S. program after 2015. In August 2005 the shuttle returned to flight, and thereafter ISS construction resumed, but NASA anticipated a restructuring to enable a Moon landing program before 2020.
On 15 October 2003 the Chinese entered the human spaceflight arena with the launch of a taikonaut, Lieutenant Colonel Yang Liwei, on a one-orbit mission. They completed a second human spaceflight, this time with a two-taikonaut crew, in 2005. China has also expressed an interest in sending humans to the Moon but has announced no timetable for such an effort.
Bulkeley, Rip. The Sputniks Crisis and Early United States Space Policy: A Critique of the Historiography of Space. Bloomington,: Indiana University Press, 1991. An important discussion of early efforts to develop civil space policy in the aftermath of the Sputnik crisis of 1957. It contains much information relative to the rivalry between the United States and the former Soviet Union, and how it was affected by the launching of the Sputnik I scientific satellite.Find this resource:
Burrows, William E. This New Ocean: The Story of the First Space Age. New York: Random House, 1998. A strong overview of the history of the space age, from Sputnik to 1998.Find this resource:
Logsdon, John M., ed. Exploring the Unknown: Selected Documents in the History of the U.S. Civil Space Program. 6 vols. Washington, D.C.: NASA, 1995–1998. An essential reference work, these volumes published more than one thousand key documents in the history of spaceflight and its development throughout the twentieth century.Find this resource:
McDougall, Walter A. The Heavens and the Earth: A Political History of the Space Age. New York: Basic Books, 1985. Reprint, Baltimore: Johns Hopkins University Press, 1997. This Pulitzer Prize–winning book analyzes the space race to the Moon in the 1960s. The author argues that Apollo prompted the space program to stress engineering over science, competition over cooperation, civilian over military management, and international prestige over practical applications.Find this resource:
Siddiqi, Asif A. Challenge to Apollo: The Soviet Union and the Space Race, 1945–1974. Washington, D.C.: NASA, 2000. The standard work on the Soviet side of the race to the Moon.Find this resource: