International Space Station

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International Space Station

November 20, 1998

The International Space Station (ISS), under construction since 1998, is the largest international scientific partnership in history. The project involves seventeen countries: the United States, the eleven member nations of the European Space Agency, Canada, Japan, Russia, Italy, and Brazil. When the ISS is completed, astronauts will have assembled a total of one hundred separate parts during forty-five missions while the station orbits 240 miles (384 kilometers) above Earth. The ISS will eventually consist of several modules, and as many as seven crew members will live on board, conducting scientific experiments and space research. By 2004 eight crews had already stayed on the ISS for months at a time. Construction had been postponed in 2003, however, as a result of the Columbia space shuttle disaster, and the future of the ISS remained uncertain. (A space shuttle is a craft that transports people and cargo between Earth and space.)

"I think … having a space station is somewhat an evolutionary step in where we are going in this next millennium."

William M. "Bill" Shepherd, Space Station Commander Expedition 1

Soviets launch first space stations

Although the former Soviet Union built the first space stations, which ultimately led to the development of the ISS, the

actual concept has roots in the nineteenth century. The idea of a space station has been traced back to "The Brick Moon: From the Papers of Captain Frederic Ingham," a story by author Edward Everett Hale (1822–1909) published in the Atlantic Monthly magazine (1869–70). "The Brick Moon" describes how Captain Frederic Ingham and his former college friends build an artificial Moon made of brick. According to Elizabeth Paulhaus, writer of the online article "Brick Moon Rising."

The first known mention of the term "space station" was made by the German rocket engineer Hermann Oberth (1894–1989; see entry) in 1923. He envisioned a wheel-like vehicle that would orbit Earth and provide a launching place for trips to the Moon and Mars. About two decades later the German-born American rocket engineer Wernher von Braun (1912–1977; see entry) proposed a more detailed concept of a space station in a series of articles in Collier's magazine. He described a giant vehicle, 250 feet (762 meters) in diameter, that would spin to create its own gravity as it orbited 1,000 miles (1,609 kilometers) above Earth.

The Soviets launched the world's first space station, Salyut 1, in 1971, during a time of intense competition between the Soviet Union and the United States. Since World War II (1939–45) the two superpowers had been engaged in a period of hostile relations known as the Cold War (1945–91), which involved not only a race for military superiority but also a race for dominance in space. In 1957 the Soviets had launched Sputnik 1, the first artificial satellite (an object that orbits in space), sending shock waves through American society. Sputnik 1 was a sign that the Soviet Union was moving ahead in the Cold War. The next year the United States responded by creating the National Aeronautics and Space Administration (NASA)—and the space race began.

In April 1961 the Soviets stunned the world again by achieving the first manned space flight when cosmonaut (astronaut) Yuri Gagarin (1934–1968; see entry) made a nearly complete orbit of Earth. The following month U.S. astronaut Alan Shepard (1923–1998; see box in John Glenn entry) made a brief but successful trip into orbit. Two years later Soviet cosmonaut Valentina Tereshkova (1937–; see entry) became the first woman in space. Then, in the early 1960s, President John F. Kennedy (1917–1963; served 1961–63) publicly pledged to put an American on the Moon by the end of the decade (see Christopher Kraft [1924–] entry). In 1969, U.S. astronauts Neil Armstrong (1930–; see entry) and Buzz Aldrin (1930–; see entry) accomplished that goal by stepping onto the surface of the Moon.

Mir: first permanent space station

By the 1970s the United States lacked funding for further Moon exploration. The Soviet Union was in a similar situation and therefore never attempted a Moon flight. Instead the Soviets focused on the Salyut program, launching seven Salyut space stations between 1971 and 1982. The United States put the Skylab space station into orbit in 1973, but it remained in space for only one year and was visited by three crews of astronauts. Soviet cosmonauts regularly traveled to the Salyuts, but they did not stay for long periods of time because the space stations did not have adequate living accommodations. Improving upon the Salyut design, the Soviets built Mir, the first permanent residence in space, which was launched in 1986.

Mir provided valuable information about building, maintaining, and living on a space station. Remaining in orbit for more than fifteen years, until 2001, it was officially taken out of service in 1999. During that time astronauts conducted nearly 16,500 experiments, primarily on how humans adapt to long-term space flight. From 1986 until 1999 the space station was almost continually occupied by a total of one hundred cosmonauts and astronauts. Among them were seven NASA astronauts, a Japanese journalist, a British candy maker, and visitors from other countries that did not have their own space programs. In 1995 Russian cosmonaut Valery Polyakov (1942–) set the record for the longest mission aboard Mir, having stayed 438 days. The same year American astronaut Shannon Lucid (1943–; see entry) set the record for a non-Russian, on a mission that lasted 188 days, 4 hours and 14 seconds.

Lucid's record was broken in 1999 by French astronaut Jean-Pierre Haigneré (see box in Claudie Haigneré entry), when he stayed nearly 189 complete days. Haigneré was also a member of the last crew to visit Mir. Before returning to Earth the crew left the space station in a standby mode, with no occupants onboard. When Russia took Mir out of service in 2001, most of the spacecraft burned up over the Pacific Ocean. The remaining remnants of the space station crashed into the Pacific in 2004.

United States and Russia strike a deal

Mir became an international effort, eventually providing a model for the ISS. Before the first two components of the ISS were launched in 1998, however, the United States had attempted to develop its own space station. In 1984 President Ronald Reagan (1911–2004; served 1981–89) provided funding to NASA for development of a space station to be named Freedom. By 1990 cost overruns and poor management had forced NASA to scale back its plans and to design a new space station, the Alpha. Confronted with continuing financial problems, NASA approached Russian officials in 1993 about collaborating on a space station that would merge the Alpha with a second version of Mir. Russia was running out of money to build a Mir 2 that would replace the retired Mir, so a deal was struck. Thus the idea for an international space station was born, and initial on-ground construction began the following year.

ISS is built in space

The ISS is being assembled in three phases, which involve shuttle missions with specific goals, such as delivering and assembling parts, transporting crews, delivering cargo and supplies, and maintaining and servicing the station. A total of twenty-eight missions had been completed by 2004. Selected highlights of the three construction phases are described below.

Phase 1 (1994–98). During the first phase the first two modules and various other elements were constructed for assembly in space. A total of seven U.S. astronauts also gained experience with living in space by spending twenty-seven months aboard the Mir.

Phase 2 (1999–2000). The second phase involved initial in-orbit construction by crews from Russia and the United States. On November 20, 1998, Russia lifted the first component, the cargo block Zarya (Sunrise), into orbit on a Proton

Working on the ISS

Upon completion the ISS will weigh one million pounds and consist of several modules, which astronauts assemble while walking in space. The main components are a port for a Soyuz rescue craft (Soyuz is a Russian space shuttle), a Russian service module, a cargo block, a NASA docking module, a U.S. habitat (living space) module, a U.S. laboratory module, European and Japanese modules for scientific experiments, and a docking port for a U.S. space shuttle. Attached to the modules are trusses (leg-like structures), which will be as long as a football field. The trusses support solar panels (devices for capturing radiation from the Sun), which provide energy for powering the station and scientific experiments. The energy is stored in radiators mounted on the trusses. Communications equipment is also installed on the trusses.

Astronauts receive extensive training in performing extravehicular activities (activities outside a space vehicle). More commonly known as spacewalks, extravehicular trips allow astronauts to work on the ISS. During a spacewalk an astronaut remains connected to the station by means of a device on his or her spacesuit, which is attached to a joint airlock module. The joint airlock module consists of two sections—a crew lock and an equipment lock. An astronaut hooks the device on the spacesuit to the crew lock when exiting the station or while spending extended periods of time outside the station. The equipment lock is used for storing gear.

A spacesuit is adjustable so it will fit different crew members. It is equipped with special features such as gloves that allow free movement of the hands, a radio that permits five people to talk with one another at the same time, and heating and cooling systems. Floodlights and spotlights are mounted on the astronaut's helmet, and the astronaut carries a jet-pack life jacket to be used if he or she is accidentally disconnected from the space station. Astronauts also work with robotic arms to assist them in maneuvering large components and in moving around work areas. While living and working on the ISS, crews must keep track of more than fifty thousand items. To facilitate this process, an electronic tag—roughly one-fourth the size of a postage stamp—is attached to each item. Astronauts read the tags with a solar-powered infrared transmitter, which can scan fifteen thousand tags per minute at a distance of up to 40 feet (12 meters).

rocket. On December 4, 1998, the U.S. space shuttle Endeavour transported the second component, the Unity node, which is a docking hub where major sections of the ISS are locked together. During this mission the Endeavour crew, which included American astronaut Ellen Ochoa (1958–; see entry),

conducted spacewalks and attached the Unity to the Zarya. The third component, the Russian-built service module Zvedza (Star), was launched on July 12, 2000. It provided initial living quarters and life support systems.

The first ISS expeditionary crew (astronauts and cosmonauts who live on the space station) was launched aboard a Soyuz capsule on October 31, 2000. The expedition commander was U.S. astronaut William M. "Bill" Shepherd (1949–); the Soyuz commander was Russian cosmonaut Yuri Gidzenko (1962–); and the flight engineer was Russian cosmonaut Sergei Krikalev (1958–). With their four-month mission the crew began living aboard the ISS. An Endeavour crew visited the ISS in December 2000 to attach a truss structure, on which they installed solar panels, radiators, and communications systems. When the solar panels were installed, the ISS became the third-brightest object in the night sky.

Phase 3 (2001–06). According to the original plan, construction of the ISS is to be completed during the third phase. A considerable amount of work was accomplished from February 2001 until October 2003. Seven more expeditionary crews lived on the station, assembling main modules and other elements. The U.S. Destiny laboratory was attached to the Unity, adding facilities for scientific research on near-zero gravity conditions in space. The Italian-made Leonardo multipurpose module was installed to provide "moving vans" that carry equipment, supplies, and experiments between the station and a shuttle. The Russian Pirs (Pier) docking port was added, a Canadian-made robotic arm was installed for use in future construction projects, and work continued on the complex truss system.

During this period three Soyuz "taxi flights" visited the ISS to exchange the old Soyuz with a new one. This means that the taxi crew left the capsule they arrived in at the space station, then returned to Earth in the old capsule. In October 2001, French astronaut Claudie Haigneré (1957–; see entry) arrived with the third taxi crew aboard the Soyuz vehicle Andromede. On this flight she became the first woman to visit the ISS and the first non-Russian woman to serve as a Soyuz flight engineer.

Columbia tragedy causes delay

Further construction on the ISS was delayed after the space shuttle Columbia accident. On February 1, 2003, the Columbia broke apart over the western United States while returning to Earth from a visit to the ISS (see Challenger Crew entry). All seven crew members were killed as pieces of the descending craft fell from the sky. The day after the incident NASA administrator Sean O'Keefe (1956–) organized the Columbia Accident Investigation Board (CAIB). On August 26 the CAIB issued a final report. The most immediate cause of the disintegration was a piece of insulating foam that had separated from the shuttle's left wing during takeoff. The missing foam left a hole through which leaking gas was ignited by the intense heat of the rocket that propelled the Columbia.

The board also found that the Columbia was not properly equipped for its mission to the ISS. Built earlier than other U.S. shuttles—the Columbia was the first shuttle to leave Earth orbit—the vehicle had been used primarily for scientific missions and for servicing the Hubble Space Telescope (see entry). On the flight to the ISS it was required to carry larger cargo, which the crew had difficulty handling because the Columbia did not have a space station docking system. The CAIB report concluded that the Columbia accident was caused in large part by deficiencies within NASA and by a lack of government oversight. The report stated that shuttle flights were becoming increasingly dangerous and that a minimum number should be flown only when necessary. Completion of the ISS was consequently postponed while NASA studied space shuttle safety issues.

For More Information

Books

Bond, Peter. The Continuing Story of the International Space Station. New York: Springer-Verlag, 2002.

Launius, Roger D. D. Space Stations: Base Camps to the Stars. Washington, DC: Smithsonian Institution Press, 2003.

Periodicals

Hanson, Torbjorn. "Deep Space 1999." Boys' Life (June 1999): p. 28.

Scott, Phil. "Eye on the Junk: Space Station Noises Renew Worry about Orbital Debris." Scientific American (May 3, 2004): p. 27.

Sietzen, Frank Jr. "A New Vision for Space." Astronomy (May 2004): pp. 48+.

Web Sites

"Human Spaceflight." NASA.http://www.spaceflight.nasa.gov/station/ (accessed on June 25, 2004).

"International Space Station." Discovery.com.http://www.discovery.com/stories/science/iss/iss.html (accessed on June 24, 2004).

Paulhus, Elizabeth. "Brick Moon Rising." International Space Station Challenge.http://voyager.cet.edu/iss/cafe/articles/brickmoonrising.asp (accessed on June 25, 2004).

"Where Is the International Space Station?" NASA.http://www.science.nasa.gov/temp/StationLoc.html (accessed on June 25, 2004).