NASA - National Aeronautics and Space Administration

An astronaut is a person who pilots a spacecraft or works in space, particularly in the space program of the United States. In Russia and the other former republics of the Soviet Union, such men and women are called cosmonauts. The cosmonaut program was a project of the Soviet Union until the country broke up in 1991. Russia then took over the program. China sent its first astronaut into space in 2003.

Astronauts and cosmonauts operate spacecraft and space stations, launch and recapture satellites, and conduct scientific experiments. The word astronaut comes from Greek words that mean sailor among the stars. Cosmonaut means sailor of the universe. Astronauts in the Chinese space program are sometimes called taikonauts. Taikonaut comes from the Chinese words tai kong (outer space).

Most U.S. astronauts work for the National Aeronautics and Space Administration (NASA). They live and train at the Lyndon B. Johnson Space Center in Houston. NASA launches astronauts into space aboard space shuttles.

NASA selects two kinds of astronauts for space flights: pilot astronauts and mission specialist astronauts. Pilot astronauts command and pilot shuttles. Most pilot astronauts are test pilots from the United States Air Force, Navy, or Marine Corps. They are paid according to their military rank.

Mission specialists work with pilots to maintain spacecraft and the equipment aboard. They also conduct experiments and launch satellites. In addition, they perform spacewalks to work outside the spacecraft.

Mission specialists may be engineers, scientists, or physicians who have extensive research experience. Those who are in the armed forces are paid according to their rank. The civilians receive salaries based on an equivalent rank in the civil service system. This system includes almost all the federal government's civilian employees who are appointed rather than elected.

A third kind of astronaut is called a payload specialist. This kind of astronaut carries out scientific experiments involving the payload (cargo) on the spacecraft. Most payload specialists are scientists who work for the owner of the payload. They must be approved by NASA.

The term astronaut also has a meaning that is not connected with NASA activities. In the 1960's, the United States Department of Defense awarded the rating of astronaut to military and civilian pilots who flew aircraft higher than 50 miles (80 kilometers). Seven test pilots received this rating for flights in the X-15 rocket plane. Flights of the X-15 ended in 1968.

Cosmonauts train at the Yuri Gagarin Russian State Scientific-Research Test Center of Cosmonauts Training, in Starry Town, also known as Star City, near Moscow. They travel into space aboard vehicles called Soyuz. Unlike space shuttles, these vehicles are not reusable. Crews lift off from the Baykonur Cosmodrome, near the Aral Sea in south-central Kazakhstan. Landings take place in remote, flat areas of Kazakhstan.

A Soyuz carries two or three highly specialized cosmonauts. The commander is almost always a military jet pilot, and the flight engineer is almost always a civilian. The flight engineer is usually a member of the staff of the design bureau responsible for the craft. On about half the Soyuz flights, a third cosmonaut, usually called the cosmonaut researcher, is aboard. This person can be a non-Russian "guest cosmonaut" or a Russian physician.

Cosmonauts began making guest flights aboard space shuttles in 1994, and astronauts began visiting Russia's Mir space station in 1995. Both astronauts and cosmonauts helped build, and then worked aboard, the International Space Station.

In the 1990's, China began developing a spacecraft designed to carry astronauts. The craft, called the Shenzhou, resembles the Soyuz and lifts off from Jiuquan Space Launch Center in northern China. Landings take place in remote areas of Inner Mongolia.

This article discusses Astronaut (Achievements in space) (Accidents in space) (Selecting the astronauts) (A look at the astronauts) (Training the astronauts) (Astronauts on the ground) (The cosmonauts).

Achievements in space

On April 12, 1961, Yuri A. Gagarin of the Soviet Union became the first person to travel in space. He orbited Earth once in a Vostok capsule.Vostok is Russian for east. Gagarin's flight lasted 1 hour 48 minutes. Twenty-three days later, on May 5, Alan B. Shepard, Jr., became the first American space traveler. He made a 15-minute flight in a Mercury capsule but did not go into orbit. John H. Glenn, Jr., the first American in orbit, circled Earth three times on Feb. 20, 1962.

The first woman in space, cosmonaut Valentina Tereshkova, was in space for 3 days in 1963. Twenty years later, astronaut Sally K. Ride became the first American woman in space. In June 1983, Ride orbited Earth with four other crew members on a six-day mission aboard the space shuttle Challenger.

In 1964, the Soviet Union placed the first three-person spacecraft in orbit. This design was called Voskhod, which is Russian for sunrise. In 1965 and 1966, the United States conducted a series of 10 two-person flights in Gemini spacecraft. During those flights, the astronauts practiced maneuvering their craft and joining it to other orbiting space vehicles.

On March 18, 1965, cosmonaut Alexei A. Leonov became the first human being to step outside a spacecraft and float freely in space. Less than three months later, on June 3, astronaut Edward H. White II made the first spacewalk for the United States.

In 1967, cosmonauts began flying the Soyuz series of spacecraft. These are three-seat vehicles, but the first crewed flight carried only one cosmonaut, and other early flights carried two. The Soviet Union also tested spacecraft to send cosmonauts to the moon and land them there. After many failures, however, the Soviets canceled their moon-trip projects.

Space flights of the Apollo program, the U.S. project to land astronauts on the moon, began in October 1968. On December 24 and 25 of that year, Frank Borman, James A. Lovell, Jr., and William A. Anders orbited the moon 10 times in 20 hours. In doing so, they became the first people to orbit a celestial body other than Earth.

On July 20, 1969, astronauts Neil A. Armstrong and Buzz Aldrin became the first people to set foot on the moon. They landed the Apollo 11 lunar module, called the Eagle, and performed scientific experiments and collected rock samples. Other astronauts made five more moon landings from 1969 to 1972. They left five scientific stations on the moon and brought lunar dust and rock to earth.

In June 1971, cosmonauts established the first space station, Salyut 1. In 1973, the United States sent up a team of astronauts to operate its first space station, Skylab. Astronauts Charles Conrad, Jr., Joseph P. Kerwin, and Paul J. Weitz live in Skylab for almost a month.

In 1975, the United States and the Soviet Union undertook their first joint space mission, the Apollo-Soyuz Test Project. On July 17, an Apollo spacecraft docked with a Soyuz craft. The Apollo craft carried astronauts Thomas P. Stafford, Vance D. Brand, and Donald K. Slayton. Aboard the Soyuz were cosmonauts Alexei A. Leonov and Valery N. Kubasov. For two days, the five spacefarers conducted experiments in the docked craft.

On April 12, 1981, the United States launched the space shuttle Columbia, the first reusable spacecraft to carry a crew. Astronauts John W. Young and Robert L. Crippen orbited Earth more than 36 times during a flight lasting about 2 days 6 hours. On Nov. 28, 1983, Columbia carried the first European-built research laboratory, called Spacelab, into space.

Cosmonaut Valery Polyakov completed a record 438 days in space on March 22, 1995. Polyakov spent this time aboard Mir. His mission helped scientists study how extended periods of weightlessness affect the human body.

Astronauts first recovered, repaired, and relaunched a disabled satellite in April 1984. Traveling aboard Challenger, they used a Canadian-made robot arm to capture the satellite. In May 1992, astronauts aboard the shuttle Endeavour captured a satellite using only their gloved hands. They then attached a special tool to the satellite so that a robot arm could hold it. In December 1993, astronauts aboard Endeavour repaired the Hubble Space Telescope. They installed a device that made up for a defect in the telescope's main mirror.

On Oct. 15, 2003, Yang Liwei became the first astronaut sent into space by China. He orbited Earth aboard a Shenzhou spacecraft for 21 hours before landing safely.

On June 21, 2004, the American test pilot Michael Melvill became the first astronaut to be launched into space by a private company. Melvill piloted a rocket called SpaceShipOne, which was built and operated by Scaled Composites of Mojave, California. The craft carried Melvill more than 62 miles (100 kilometers) above Earth on a brief suborbital flight.

Accidents in space

Space travel is risky, and a number of astronauts and cosmonauts have lost their lives in training or on space flights. The first fatality in a space program occurred on March 23, 1961. Valentin V. Bondarenko, a Soviet cosmonaut trainee, died in a fire in a pressure chamber.

During a ground test on Jan. 27, 1967, an Apollo spacecraft caught fire, killing the three astronauts inside. The astronauts -- Virgil I. Grissom, Edward H. White II, and Roger B. Chaffee -- had been scheduled to fly the first Apollo spacecraft.

On April 24, 1967, cosmonaut Vladimir Komarov became the first person to die on a space flight. Komarov's flight was the first in which a Soyuz vehicle carried a cosmonaut into space. When Komarov tried to land the vehicle, its parachutes failed to open properly. Komarov died when the Soyuz crashed to earth.

The first mission in which people occupied a space station also ended in disaster. In June 1971, Georgi T. Dobrovolsky, Victor I. Patsayev, and Vladislav N. Volkov boarded the experimental station Salyut 1 from their Soyuz 11 spacecraft. During their 23-day mission, they conducted medical examinations of one another and carried out scientific studies. On the return flight, all three cosmonauts died because of a sudden loss of cabin pressure in the Soyuz.

On Jan. 28, 1986, Challenger broke apart shortly after launch. All seven crew members were killed. They included Christa McAuliffe, a teacher, who was aboard as part of a program to make the experience of space flight better known to the public. After the Challenger disaster, NASA canceled this program and suspended all shuttle flights. Astronauts returned to space on Sept. 29, 1988, aboard the shuttle Discovery. Discovery's rocket boosters and many other features of the craft had been redesigned as a result of the Challenger disaster. On Feb. 1, 2003, the shuttle Columbia broke apart as it reentered Earth's atmosphere. All seven astronauts on board were killed.

Selecting the astronauts

The first seven U.S. astronauts, selected for the Mercury program, were, left to right, Donald K. Slayton, Walter M. Schirra, Jr., Gordon Cooper, M. Scott Carpenter, Virgil I. Grissom, John H. Glenn, Jr., and Alan B. Shepard, Jr. Image credit: NASA

NASA accepts applications for pilot astronauts and mission specialist astronauts on a continuing basis. A selection board normally picks a group of about 15 to 25 candidates every two years. An applicant must be a U.S. citizen and must hold a bachelor's degree or higher in engineering, a biological science, a physical science, or mathematics. There is no age limit, but every candidate must pass the NASA space flight physical examination.

Pilot astronaut candidates must have flown for 1,000 hours as a command pilot in high-performance jet aircraft. They must be between 5 feet 4 inches and 6 feet 4 inches (163 and 193 centimeters) tall. Candidates for mission specialist do not need flight experience, but they must have at least three years of related professional experience. They must be between 5 feet and 6 feet 4 inches (152 and 193 centimeters) tall.

A look at the astronauts

Since 1959, more than 250 astronauts have flown in space. NASA chose seven test pilots as the first group of astronauts and introduced them to the public on April 9, 1959. The group consisted of Air Force officers Gordon Cooper, Virgil I. Grissom, and Donald K. Slayton; Navy pilots M. Scott Carpenter, Walter M. Schirra, Jr., and Alan B. Shepard, Jr.; and Marine Corps pilot John H. Glenn, Jr. In the 1960's, NASA selected an additional 49 experienced jet pilots. From 1965 to 1967, NASA picked 17 scientist astronauts.

Shannon Lucid, an American astronaut, set the world record for time in space by a woman. In 1996, she spent 188 days in space, mostly aboard the Russian space station Mir. Image credit: NASA

In 1978, NASA announced the selection of astronauts for upcoming flights of the space shuttle. In this group were 15 pilot astronauts and the first 20 mission specialists. Among the mission specialists were the first six women selected to become astronauts. All six held doctor's degrees. They were physician Anna L. Fisher, biochemist Shannon Wells Lucid, electrical engineer Judith A. Resnik, physicist Sally K. Ride, physician Margaret R. Seddon, and geologist Kathryn D. Sullivan. In 1990, NASA chose the first woman to become a pilot astronaut, Eileen Marie Collins.

In 1983, Canada selected six of its citizens to receive training for NASA missions. The next year, Marc Garneau, a commander in the Canadian Navy, flew aboard Challenger. He thereby became the first Canadian astronaut to travel in space. NASA has also flown payload specialists from Belgium, France, Germany, Israel, Italy, Japan, Mexico, the Netherlands, Saudi Arabia, Ukraine, and the former West Germany.

In 1985, Senator Edwin J. (Jake) Garn of Utah became the first elected official to fly in space. He was chairman of the Senate committee that had oversight responsibilities for the NASA budget. Garn flew aboard Discovery. The next year, Congressman C. William Nelson of Florida flew aboard Columbia. In 1998, John Glenn, then a U.S. senator, returned to space aboard Discovery. He was 77 years old at the time of the flight, making him the oldest person ever to travel in space.

Training the astronauts

Candidates for pilot and mission specialist undergo one year of general training at Johnson Space Center. After successfully completing this training, they become astronauts. The training involves two major phases: (1) a general phase, involving classroom work, flight training, and survival training; and then (2) more specific basic mission training and advanced mission training.

Classroom work

NASA brings in instructors from its research centers and from universities to teach aerodynamics, physics, physiology, computer science, and other subjects. Experienced astronauts lecture on such topics as how to communicate with astronauts in space. Other NASA personnel discuss the people, equipment, and funding that make space flight possible.

Mercury and Gemini astronauts took courses in rocket engines, flight mechanics, and navigation. In addition to those subjects, Apollo astronauts studied the geology of the moon. They also traveled to Hawaii, Iceland, Alaska, and other places to study volcanic rocks similar to those on the moon. Skylab crews took classes in astronomy, geology, and life sciences to enable them to perform experiments and make observations.

Flight training

Flight training takes place in T-38 jet aircraft. Once mission specialist candidates learn to operate the aircraft , they fly about 4 hours per month. Pilot candidates must fly 15 hours. Pilots are also trained on a special airplanes called Shuttle Training Aircraft (STA). These airplanes are designed to perform as a space shuttle does during landing.

Survival training

Survival training teaches candidates how to survive after an unplanned landing in water or in a forest. Before shuttle flights, returning spacecraft landed in the ocean. The space shuttle lands on a runway, but astronaut candidates prepare for emergency bailout over water from shuttles and T-38's. For example, they are towed through the water in a parachute harness to simulate being dragged by a parachute in a wind. In addition, candidates practice survival training in the wilderness.

Basic mission training

Basic mission training involves the study of cockpit layout and flight-control systems. During such training, candidates also prepare for the actual conditions of space flight.

Candidates for pilot and mission specialist train for weightlessness in two ways. They experience the near absence of gravity as large airplanes fly through a series of arcing climbs and dives. For about 30 seconds during each arc, they float weightlessly in the padded body of the aircraft. Floating in water also simulates (reproduces conditions of) weightlessness. The tanks used for training purposes are known as the Weightless Environmental Training Facility (WETF) and the Neutral Buoyancy Laboratory (NBL).

After successful completion of the training program, new astronauts continue to develop their skill while they wait for crew assignments. Some become experts in several support or operational areas.

Advanced mission training

Once assigned to a crew, astronauts spend most of their time training in simulators. Shuttle astronauts train in the Shuttle Mission Simulator (SMS). This device can reproduce the events of an entire mission. Crew members spend as many as eight hours a day in the simulator. Instructors continually give the crew problems to solve to prepare them for emergency situations.

Training in simulators is valuable preparation for what the astronauts may later face on actual flights. For example, in 1970, the Apollo 13 astronauts used the oxygen and power supply of their lunar module to return home safely after an explosion damaged their main spacecraft. This operation was less difficult to carry out because the crew was very knowledgeable about all systems on board.

Astronauts also train in mock-ups -- that is, full-sized models of the spacecraft. Mock-ups are used to practice working and living in the close quarters of spacecraft. The astronauts store items, prepare foods, and check equipment in the mock-ups. They also practice entering and leaving the spacecraft.

Advanced training prepares astronauts for tasks that are not part of all missions. For example, astronauts involved in the 1975 Apollo-Soyuz project and the visits to Mir in 1995 learned the Russian language. They also studied the operation of Russian space vehicles. Astronauts who worked in the Spacelab practiced operating special equipment and instruments needed to conduct experiments. Astronauts preparing for spacewalks receive extra training in the WETF and the NBL. They also train with virtual reality systems.

Astronauts on the ground

Astronauts taking part in a space mission work on the ground as well as in space. Those on the ground relay information and instructions from flight controllers, engineers, and scientists to the crew. If problems develop, other astronauts help engineers find solutions.

Astronauts have helped change the design of spacecraft and their operating systems. For example, Mercury astronauts insisted on a window in the capsule and a hatch that opened from the inside. Also, skill displayed by the astronauts led designers to give them more control over flying the craft. Shuttle astronauts worked on the location of instruments and the modification of space suits. They also helped develop special equipment, such as satellite repair tools

The cosmonauts

Since April 1961, about 100 cosmonauts have flown in space. Most of them have been from the Soviet Union and, since 1991, Russia. The first cosmonauts were military pilots. Most were in their middle 20's, and many were sent to college after returning from space. Since 1964, crews of cosmonauts could include civilian engineers and physicians.

The first cosmonauts spent less than two years in training. The original training program involved constant athletic activity. It included swimming, running, cycling, and parachute jumping over land and water. The U.S. program did not require such activities, but the astronauts were expected to get into good physical condition on their own.

The early Soviet program also included training in heat chambers and an isolation cell. They also sat in a spinning, swinging chair that was designed to test for motion sickness.

As the Soviets became more experienced in space travel, they learned that training did not need to be so demanding. They eliminated the heat and isolation chambers, and required less parachute jumping. In addition, motion sickness training became easier. Today, cosmonauts spend most of their time studying complex spacecraft systems and working in simulators. They now spend several years preparing for space flight.

The Soviet Union and Russia have sent guest cosmonauts into space since 1978. These cosmonauts' home countries include Afghanistan, Austria, Belgium, Bulgaria, Cuba, Czechoslovakia (now the Czech Republic and Slovakia), the former East Germany, France, Germany, Hungary, India, Italy, Japan, Kazakhstan, Mongolia, Poland, Romania, Slovakia, South Africa, Syria, Ukraine, the United Kingdom, the United States, and Vietnam.

Contributor: James Oberg, M.S., Spaceflight Engineer; author, UFOs and Outer Space Mysteries.

How to cite this article: To cite this article, World Book recommends the following format: Oberg, James. "Astronaut." World Book Online Reference Center. 2005. World Book, Inc. http://www.worldbookonline.com/wb/Article?id=ar034800.

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