Space Stations

Summary

Space stations are Earth-orbiting vessels operated by national and international space agencies to study space and the Earth. Manned space stations are designed to be semipermanent habitats for working astronauts and scientists and are considered prototypes for human living environments in space. They do not have dedicated propulsion systems but are instead placed in space by other vehicles. This often means they are built throughout several missions. The International Space Station (ISS) is an orbiting space station inhabited by astronauts and operated by several nations, including the United States, Japan, Canada, Russia, and member nations of the European Space Agency (ESA).

Definition and Basic Principles

Space stations are Earth-orbiting vessels operated by national and international space agencies to study space and the Earth. Space stations differ in design and purpose from other types of spacecraft, such as rockets and space shuttles, because they serve an entirely different purpose. Space stations are built for long-term orbit around Earth, and they are intended to carry more crew members than other types of spacecraft. They are also intended to be laboratories for the study of space science and earth science. An important aspect of space station research is the astronauts and scientists themselves. Their physical responses to being in zero-gravity environments and their psychological responses to living in space for long periods (far longer than typical space missions) help scientists understand the requirements for off-Earth human and animal habitats.

The design of space stations has evolved since the first space station missions of the early 1970s. The space stations of the Salyut and other programs were monolithic structures, so-called because they were designed as centralized spacecraft. Later, space stations favored modular designs that allow diverse elements to be added as needed. For example, the ISS comprises several modules that have been added over several years. The most common uses of space stations by scientists are as laboratories for experiments in various life and material sciences.

Background and History

In science fiction, the space station has long held a place of special interest because it offers a glimpse into what life aboard an inhabited spacecraft might be like. Whereas sending rockets to the Moon and beyond answers questions about how far away from Earth and how fast humankind can travel, space stations answer the more fundamental questions of whether humans can live in space and for what length of time. The answers to these questions may provide a positive, long-term direction for the future of humans in space.

The first space station in orbit around Earth was the Salyut 1, the first of several Soviet space stations launched between 1971 and 1982. Despite its overall success, the mission ended in tragedy when a depressurization accident resulted in the deaths of its three crew members. Other early Salyut missions were plagued with system failures and equipment malfunctions. Still, later missions were large-scale successes, partly because of the increased duration of their time in orbit, the vast amount of data gathered about the effects of space environments on the human body, and the overall viability of space stations as research laboratories.

The first US space station was Skylab, launched in 1973 after several years of development by the National Aeronautics and Space Administration (NASA). Like Salyut and other Soviet missions, Skylab had its share of problems, such as the loss of a micrometeorite shield, but it was an important first step in establishing a US space station program. In the years since these early missions, many improvements have been made to the overall concept and design of space stations, and space stations have continued to return vital information to the scientists and astronauts tasked with designing the next generation of Earth-orbiting laboratories.

How It Works

Design and Uses. The design and uses of a space station differ from other types of spacecraft. Some vehicles, such as satellites, probes, and flyby craft, are unmanned vehicles whose flight may or may not be dedicated to a specific orbit and whose small size helps extend the duration of their missions. For example, the probe Voyager 1 has regularly transmitted data about the Sun's heliosphere since it left Earth in 1977. The probe, which will not return to Earth, was built to have enough power to last until 2025 to 2030. Other vehicles, such as space shuttles and staged rockets, are built to accommodate human passengers. These vehicles are controlled by their crew with aid from a mission control center and are launched into space from Earth. These vehicles commonly lose rocket systems after launch and only the manned vehicular portions return to Earth. The spacecraft used in the Apollo program, for example, was built to be used as exploration craft on the lunar surface with provisions for temporary human habitation and were also built as return vessels. Like space stations, shuttlecraft are used for scientific research but are not intended to be inhabited for long periods. Shuttlecraft are also used as vehicles between space stations and Earth.

Architecture. Manned space stations are designed to be used as semipermanent habitats and laboratories. Therefore, they are roomier, have more advanced life-support systems, and are technologically more complex than other space vehicles. The ISS exemplifies this design consideration. It is about 240 feet long and 356 feet wide, with more than 12,000 square feet of room to live and work. It is also modular, with solar arrays, pressurized living and research modules, connector nodes, storage modules, and other pieces all connected around a central truss system. Each piece of the ISS is launched into space (either aboard a shuttlecraft or rocket) and locked into place.

Mission Duration. An ever-evolving aspect of space stations is the duration of their missions in space. The Salyut 1 mission launched in April 1971 and returned to Earth in October after 175 days. The Russian space station Mir launched in February 1986 and returned in March 2001 after 5,510 days in orbit—nearly ten years. The ISS was launched in 1998 and eventually surpassed Mir's record. Future space station designs are expected to extend these periods, leading to semipermanent living and working facilities that will be operable for decades or more. The obstacles that must be overcome to make this happen involve funding and political issues, as well as the outcomes of continuous research on the long-term effects of these environments on humans.

Applications and Products

Space stations have many applications, including scientific research stations, prototypes for permanent Earth-orbiting human settlements, and tools for international diplomacy. Because they have been used for a relatively short time in any of these capacities, their potential is still mostly unrealized, at least in terms of how they were once envisioned by space scientists and science-fiction writers. However, if private entities continue to develop their plans for space stations, perhaps they will create uses that go beyond previously envisioned ideas.

Science and Research in Space. One of the benefits of the space station design is that it can allow humans to carry out scientific research. Scientific research has long been a primary reason for sending manned and unmanned vehicles into space. However, depending on one's orientation, this is only sometimes the most important reason for spaceflight. Consider the attitudes of the Mercury Seven, the first seven astronauts selected by NASA, many of whom thought of themselves as pilots first and scientists second (if at all). Although there is value in using space missions to test a nation's technological capabilities and explore the environs, there is no doubt that space exploration, with the primary goal of scientific discovery, has many benefits. For example, the effects of space weather and atmospherics on animals and plant life are important areas of knowledge if living in space is to be an option for the human race.

The science performed aboard the ISS illustrates the breadth of the research that can be accomplished. From 2007 to 2009, for example, crew members photographed portions of Earth from space, and these data were used to supplement climate change studies. Other studies have focused on space farming, cellular growth, new treatment options for Duchenne muscular dystrophy (DMD) through the study of protein crystal growth, and the development of telemedicine strategies, which could be used to aid injured people across great distances. Other studies focused on conditions like Alzheimer’s disease by studying protein clusters causing neurodegenerative diseases, cancer by studying the growth of endothelial cells supplying blood in the body, and asthma.

Human Habitats in Space. Humans in space face dangers and problems such as space radiation, temperature extremes, decompression sickness, and the negative effects of a zero-gravity environment on humans. Designers and engineers have had some success in finding ways to mitigate and even eliminate the danger of radiation and extreme temperatures. Still, the negative effects of a zero-gravity environment may be harder to combat. Humans may have to learn to adapt to zero gravity. However, only a limited number of people have ever been in space. Therefore, it may take many more trips into zero gravity for scientists to catalog the effects on all physiological types. Other worries for astronauts include cardiovascular problems, loss of bone density, muscular atrophy, and many other issues that can lessen their productivity and even cause life-threatening conditions.

Research is helping scientists understand how to create better and more efficient habitats for humans in space. Other areas of study include determining what materials best shield astronauts from radiation, which recycling methods are most effective and provide the most long-term benefits to human-inhabited space settlements (large or small), and how to generate power from limited resources.

International Makeup. During the space race—from the 1950s to the mid-1970s—the United States and the Soviet Union competed for dominance in space. As primary players in this worldwide drama, each nation's diplomatic and political strength was tied to its success in space. For many years, "success" in this race meant the ability to launch people into space and return them safely to Earth. The United States scored a major victory by becoming the first nation to set foot on the moon. However, the lunar missions were only one point in this race—other measures of success were met handily by the Soviets, including regarding space stations with their launch of the Salyut program in the early 1970s. In 1975, the space race effectively ended when both sides teamed up for the Apollo-Soyuz Test Project (ASTP). Although this mission yielded some scientific research results, its primary importance was launching a scientific détente between the two nations.

There have been many international missions in the years since Apollo-Soyuz, including a joint program combining the resources of the US space shuttle program with the Russian Mir program, a predecessor to the ISS. The ISS combines the resources of NASA, the Canadian Space Agency, the European Space Agency, the Japan Aerospace Exploration Agency, and the Russian Federal Space Agency. As space exploration and settlement become more relevant topics on the world stage, this spirit of international cooperation could prove beneficial. However, several nations, including China, India, and Japan, appeared eager to develop their own programs. In 2011, China launched its first space station, Tiangong-1, followed by Tiangong-2 in 2016. The original craft returned to Earth on April 1, 2018. Applying information learned from the two previous stations, China launched its Tiangong Space Station (TSS) in 2021 and began permanent habitation of the station in mid-2022.

Future Studies. Research done in space could help study the long-term effects of weightlessness on the human body, which could help make adjustments before sending astronauts to Mars and beyond. It could also facilitate research in fluids, combustion, life support systems, and the radiation environment.

Monitoring Natural Disasters. The ISS SERVIR Environmental Research and Visualization System (ISERV) allows scientists to better predict natural disasters and effectively plan a response. As the ISS passes over much of Earth’s area in a day, the images from orbit can help to combat floods, fires, volcanic eruptions, deforestation, harmful algal blooms, and other calamities by providing them to the international community.

Careers and Course Work

Compared with medicine or other areas of science, the history of space station–related jobs is short. However, this short history has also revealed many areas where inventiveness and innovation are major student assets. Anyone considering a career in space stations has much to consider regarding fields of study and potential careers.

Areas of focus for those wishing to build or design space stations are astronautics and space engineering, as well as robotics and embedded systems. Certain universities offer aeronautics and astronautics schools, where students work on next-generation technologies and techniques that will someday be part of space stations and other missions. Graduates from these and similar programs often go on to careers in the aerospace industry and NASA. NASA itself is heavily involved in educational programs for institutions of all sizes and levels, with the purpose of educating students about its missions and letting students know how they may become part of the space program as employees.

Those seeking to become astronauts aboard a space station should earn at least a bachelor's degree (a higher degree is desired) in engineering, biology, physical science, or mathematics. These types of degrees are available at most larger universities and colleges. To pilot a spacecraft, a person must accumulate at least one thousand hours as a pilot in command of a jet aircraft. Astronauts also must have perfect vision and be between 62 and 75 inches tall. Actual training for being an astronaut comes after acceptance into NASA's astronaut training program. Universities like American Military University in West Virginia and Rice University in Texas offer courses in space science. Aspirants can work in organizations such as NASA, United Space Alliance, SpaceX, Boeing Co., and Virgin Galactic.

Social Context and Future Prospects

The importance of space stations as research laboratories for space and earth sciences was realized long before the first station was launched, which may account for the continuation of space station programs. However, space stations are important for many other reasons. First, space stations allow national and international space agencies to expand and improve their knowledge of space environments and the potential of space stations as semi-permanent or even permanent habitats for humankind. Second, space stations offer an unprecedented opportunity for nations to experience a form of diplomacy and sharing of resources that could serve as a future model of foreign relations. Third, if the quest for new ways to understand the environment is to continue, that search must be extended into space to maintain an essential perspective that had been unavailable. Space stations are invaluable tools for extending how humankind learns about itself and its environment.

Specific future applications of space stations are difficult to predict. They may someday be used as educational institutions, vacation getaways, or way stations between Earth and other spacecraft, or they may remain as they are while other space missions attempt to fly to and from Mars and beyond. Because of the expenses involved in building and maintaining space stations, their benefits must outweigh their costs, and there must be a favorable political and social climate. By the 2010s, it appeared increasingly likely that private endeavors would play a major or dominant role in future space station development, in contrast to the established government-sponsored model.

In the late 2010s, space stations served as extensions of past discoveries in science, technology, and engineering. As their capabilities are further explored, it may be that humankind can derive even greater benefit from them. In 2018, US President Donald Trump advised privatizing NASA to end federal support of the agency. Though this did not happen, NASA started collaborating with the private sector for its Artemis program to put the first woman on the moon.

In the 2020s, studies conducted by scientists on the ISS included producing more cotton with less water by studying cotton plant root systems, drug tests to improve health in space, and research on materials used for high-temperature manufacturing in microgravity. Scientists gained a deeper understanding of granular materials, which allows for better spacecraft design and better semiconductor materials. Improved ultrasound technologies enhanced the detection of psychological changes and the understanding of coordinated function in brain activity.

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