Is the International Space Station the appropriate next step for humanity's exploration of space?

Viewpoint: Yes, the ISS provides an effective platform from which manned exploration of the solar system can begin, and it represents an important model for international cooperation.

Viewpoint: No, the ISS is a poor use of valuable space exploration funds, and its low-earth orbit can do little in the way of generating creative new strategies that will make the exploration of distant locations in the solar system more feasible.

Space exploration must take place first in our imaginations. There, dreams and plans can flourish unencumbered by the drab realities of political, financial, and technological constraints. To assess the future of man's activities in space, we must ask both if we are moving toward the ultimate satisfaction of our ideal goals for exploration, as well as whether we are best using our limited resources right here and now. The International Space Station (ISS), the focus of space exploration at the start of the twenty-first century, has been a source of controversy since it was first proposed in the 1970s. The program to build the station was begun in 1984, and it was ready to begin hosting astronauts approximately 14 years later. Transformations in science, technology, medicine, and politics that took place in the intervening years have only made the International Space Station more controversial.

The proponents of the International Space Station argue that it provides an effective platform from which manned exploration of the solar system can begin. They suggest that living on the station will introduce astronauts to some of the physiological challenges likely to be presented by interplanetary visits. Experiments to be performed on the station will guide the design and production of systems for use in space environments. Advocates also hope that technological benefits, such as improved drug production, can be achieved for earthly uses as well.

The International Space Station has also produced a number of socio-political achievements. It is a fine example of successful international collaboration, involving the participation of 16 nations. Public interest in space has been stimulated by activities at the ISS, including the unintended publicity surrounding the visit of Dennis Tito, an American millionaire who—in the company of Russian cosmonauts and very much against the wishes of his countrymen at NASA—became the first space tourist in 2001.

But many interested in the future of space exploration charge that the ISS is not merely a poor way to spend limited resources. They argue that it fails the imagination as well, and that it will impede, not advance, the ultimate goal of man's exploration of the solar system. In many ways, the ISS is too similar to previous space stations Skylab and Mir, and even to the space shuttles. For example, it provides the same sort of micro gravity environment for scientific experiments that have already been provided by other space stations, and advances in our understanding of micro gravity—made during the long construction period of ISS—have rendered many of its planned experiments and projects redundant or even obsolete. Other developments, such as the evolution of a private sector-based space exploration industry, have changed the social, political, and economic context of the ISS.

Critics of the ISS also charge that it will do little or nothing to speed our access to more remote locations in space. In order for man to visit Mars or other planets in our solar system we must not only design new technological systems, we must also find strategies that change the economic constraints of space travel by taking advantage of things that can reduce the cost—for example, finding ways to utilize minerals and energy present on the Moon or Mars—while minimizing expensive efforts such as transporting heavy cargo from Earth's surface. The low-earth orbit of the ISS can do little in the way of generating creative new strategies that will make the exploration of distant locations in the solar system less expensive.

The future of the ISS is closely connected to the goals and constraints of society. Was the ISS a mistake, a timid half-step that has only taken away resources from bolder initiatives such as the colonization of Mars? Or is it a proud international achievement that has provided both a model for future international cooperation and a platform from which space exploration can advance? The answer is still being debated.


Viewpoint: Yes, the ISS provides an effective platform from which manned exploration of the solar system can begin, and it represents an important model for international cooperation.

The International Space Station, a technological marvel, is a bold and visionary achievement that has reaffirmed our commitment to making humankind's age-old dream of space exploration a reality. Furthermore, work on the station will not only expand our knowledge of medicine, physics, chemistry, and biology, but also provide insights into technological advances that will help build stronger economies on Earth.

The very existence of the ISS is a blow to arguments, dating back to the 1970s, that were voiced by critics who claimed that a space station wasn't needed, that it was an inappropriate "next step." The space station was needed then, and it is still needed now—not just for the reasons of science and national prestige that were first argued by its advocates back in the 1970s and 1980s, but for even more important reasons. The ISS has promoted international cooperation, helped ensure peaceful co-existence and prosperity among nations, and has helped keep the dream of space exploration alive.

No one can deny that the ISS is one of the most challenging technological, managerial, and political tasks ever accomplished by humankind. It has also become a public relations bonanza for those who support the space program. According to these supporters, the very existence of the space station has generated greater public interest in further space exploration. By engaging the public, the ISS helps humanity maintain its focus outward, toward the heavens. And as we live and work on the space station—and even visit like millionaire Dennis Tito—the media will continue to spotlight developments and generate interest and support for the space program. That focus may eventually cause us to take the next, "next step," whether it be a return to the Moon or a manned mission to Mars.

Critics of the ISS have stated that too much money has been spent on the station, when it could have been better spent here on Earth. But these critics fail to realize that the $50 billion-plus cost in the construction and maintenance of the ISS has been spent right here on the planet. It has helped fuel the economies in the 16 nations that cooperated to make the space station a reality. Money for the construction of the station supported the creation of thousands of jobs for highly skilled workers, including U.S. and Russian engineers who worked side by side on the space station instead of on projects involving armaments and missiles.

The argument against the ISS has always been that it cost too much, and that it was the wrong route to take to advance space exploration. Critics charged that the building of the ISS would turn out to be an orbital White Elephant, a colossal waste of time and money. Historically, such arguments have often been shortsighted. The "White Elephant" critics will be right only if they succeed in convincing citizens around the world that they should turn their backs on space exploration.

The ISS—A Platform for Further Space Exploration and Medical Research

The idea of a manned orbiting structure astonishingly predates the birth of motorized flight. In 1857, author Everett Hale's science fiction narrative, "The Brick Moon," was published in the Atlantic Monthly. The possibility of humanity creating a station in space as a base for further exploration was first proposed by Russian rocket

The service module of the International Space Station on display in Russia prior to its launch. (Photograph by Yuri Kadobnov. © AFP/Corbis. Reproduced by permission.)
The service module of the International Space Station on display in Russia prior to its launch. ( Photograph by
Yuri Kadobnov. © AFP/Corbis.
Reproduced by permission .)
designer Konstantin Tsiolkovsky in 1912, only nine years after the Wright brothers flew for the first time. In the 1920s and 1930s, German rocket scientists Werner Oberth and Werner Von Braun and other early rocketship pioneers also postulated a space station as a departure point for interstellar exploration. The ISS is the realization of the dreams of these early pioneers.

The ISS also provides opportunities for learning to manage extended stays in space, experience vital for exploration of the Moon, Mars, and the solar system. For proof of the role ISS will play in this new era of exploration, look no further than the multinational effort behind it. (This effort is further examined in the following section.)

"We need longer missions in space—missions that last months or even years," testified noted heart surgeon Michael E. DeBakey in 1993. His point was that space-station research on ways to combat the effects of weightlessness on the human body could yield "countermeasures that could be applicable to the aged and feeble, as well as astronauts." Better treatments for the bone loss of osteoporosis is one advance widely expected.

Undeniably, advances in biology, medicine, and physics will occur as a result of experiments that could not be conducted on Earth. Those advances will create new opportunities for financial empires just as early space research resulted in the development of new consumer products and materials such as Teflon non-stick coatings on pots and pans, heat-and cold-resistant ceramics, and solar cells that energize sun-powered calculators and automobile batteries. Future research aboard the ISS holds promise of delivering even greater consumer benefits. For instance, goals proposed for future ISS-based research include the development of purer, more powerful, but less toxic, forms of drugs that could be used to treat diseases ranging from AIDS and cancer to emphysema and high blood pressure.

As Aviation Week and Space Technology (February 1999) editorialized in a column entitled "The Space Station Wins on Cost-Benefit Analysis," "The station will dramatically improve our ability to live and work in space over the long-term. In the coming years, the station will also be the genesis of numerous medial, scientific, and technological discoveries that will benefit and inspire humankind for generations to come—and its critics will be long forgotten."

Those outcomes, when they occur, will convince future historians that Donald R. Beall, chairman and CEO of Rockwell International Inc., was right when he argued in a June 9, 1993, USA Today newspaper column that the then U.S. Space Station should be built. At that time, he called it the "next logical step in the exploration and habitation of space." He was right then and he is right today. In the future, we may very well look at the money invested on the construction of the ISS in the same way that we now look back at the relatively paltry sums that were spent on the acquisition of the Louisiana Purchase by Thomas Jefferson or the purchase of Alaska, which at that time was called "Seward's Folly." The perspective of time has revealed that those purchases were not only excellent investments, but actual bargains!

The ISS—A Symbol of International Cooperation and Peacemaking

Never before have so many space-faring nations pooled their interests, expertise, resources, and facilities to such an extent and for such an important venture. The creation of the International Space Station, the largest peacetime engineering project in history, was a 15-year struggle accomplished against enormous engineering and political odds. As such it represents a triumph of human will and cooperation.

"The ISS is the most cooperative international peacetime venture since the formation of the United Nations," wrote Fred Abatemarco in a Popular Science article published more than a half-year before the actual opening of the space station. As Popular Science also pointed out in a later article that celebrated the first visit of American and Soviet cosmonauts to the newly completed station in December 1998, "Only in war have nations come together on a larger scale."

Thus, it can be factually argued that the ISS has contributed to and will continue to contribute to World Peace, a peace that is likely to encourage further economic productivity and progress.

As the international teams of astronauts, scientists, and engineers live and work and share trials and triumphs on the ISS, most of humanity will vicariously share their grand adventure through broadcast, the Internet, and other media coverage. These explorers are likely to encounter unexpected challenges and difficulties, but those obstacles will be seen in retrospect as opportunities that produced unanticipated discoveries and rewards.

Indeed, the successful collaboration in creating and operating the ISS may, in the future, be seen as the cornerstone on which a lasting peace between Earth's suddenly not-so-far flung peoples was built. Thus, it is appropriate that the symbol of the ISS is a montage that includes four elements: a background of stars representing the conquest of space, a chain bordering an image of Earth that symbolizes the millions of people around the world who have worked to build the station, a five-pointed star representing the five national space agencies involved, and a laurel wreath symbolizing peace.


Viewpoint: No, the ISS is a poor use of valuable space exploration funds, and its low-earth orbit can do little in the way of generating creative new strategies that will make the exploration of distant locations in the solar system more feasible.

In April 1997, physics professor Robert Park from the University of Maryland-College Park testified before the Committee on Science subcommittee on space and aeronautics on the International Space Station. He was also director of public information for the American Physical Society (APS), a 40,000-member professional organization of physicists, many of whom worked in the space program or on technologies that made it possible.

According to Park, at a time when opportunities for scientific discovery in space had never been greater, many physicists and experts in the biological sciences felt the space program's priorities are seriously misplaced.

"The space station," he said, "stands as the greatest single obstacle to the continued exploration of space." In a period of sharp NASA budget cuts, the ISS is a fixed cost that was exempted from the cuts, and whose construction cost overruns were balanced, he added, "by postponing what little science is planned for the station. The result has been the near paralysis of planetary exploration."

And Park isn't the first to say so. The Space Studies Board was established in 1958 to give external, independent scientific and program guidance in space research to NASA and other government agencies. In March 1993, Space Studies Board Chair Louis Lanzerotti sent a letter to NASA Administrator Daniel Goldin. NASA had announced it would conduct a sweeping review of the space station program—

"The current redesign efforts should be based on a realistic assessment of the depth and pace of America's commitment to human exploration of the inner solar system [Lanzerotti wrote]…If the goal of human exploration is superseded as the premise for the nation's space station program, planning and implementation of orbital research infrastructure should be adjusted to meet the requirements of the new objectives efficiently and cost-consciously. We must recognize, however, that such decisions might significantly delay the nation's option for human expansion into the solar system."

From its beginnings in 1984, when Ronald Reagan launched the program to build a permanently occupied space station in Earth orbit, the station was seen as a testbed for exploration technologies. There, fledgling spacefarers would learn to build and operate space habitats, prevent microgravity damage by establishing evidence-based medical knowledge and understanding the ecology of closed environments in space, and work together in small isolated international crews.

Now, not quite 20 years later—after many redesigns, cost overruns, and delays—the habitat is built and an international crew is working together. But as a testbed for exploration technologies, many experts consider the space station a typical U.S. space enterprise.

During a CNN Interactive special in November 1999, former NASA historian and Duke University history department chair Alex Roland described the future of space travel in the second millennium as "more of what we've had for the last 30 to 40 years, which is, at considerable risk and great expense, sending humans up into low orbit—[who] float around and look busy and come back to Earth—and not really accomplishing very much."

Scientifically speaking, according to Robert Park, in the official view of the American Physical Society, there's no justification for a permanently manned space station in Earth orbit. The reason? The International Space Station (ISS) is "yesterday's technology and its stated scientific objectives are yesterday's science."

Park cited lessons learned from Skylab , the first space station, abandoned in 1974 because the scientific return didn't justify its cost; 83 space shuttle missions, starting in 1981; and the Russian space station Mir , launched in 1986 and continuously occupied for 10 years—

An artist's rendering of the International Space Station as it looked on November 8, 2000. (© Reuters NewMedia Inc./Corbis. Reproduced by permission.)
An artist's rendering of the International Space Station as it looked on November 8, 2000. (
© Reuters NewMedia Inc./Corbis.
Reproduced by permission .)

  • The microgravity environment is more harmful to human health than suspected—damage includes osteoporosis, muscle atrophy, diminished immune function, and chronic diarrhea.
  • Astronauts in Earth orbit are exposed to cosmic and solar ionizing radiation at levels far greater than those tolerated for workers in the nuclear industry—levels high enough to raise concerns about central nervous system damage.
  • The risk of a catastrophic encounter with orbital debris has grown substantially since 1984. Plans call for the station to maneuver out of the path of debris large enough to track, but smaller debris can penetrate the hull.

Microgravity is the only unique property of a space station environment, and the station was originally seen as a microgravity research lab. But, in the physical sciences, research completed on the shuttle or Mir produced no evidence that a microgravity environment has any advantage for processing or manufacture. A few basic experiments in areas like turbulence and fluid phase transitions might benefit from a micro-gravity environment, but they aren't high-priority experiments and could be conducted on unmanned platforms or on the shuttle.

And in the biological sciences—

  • Experiments on the shuttle and Mir established that flies, plants, and small mammals can go through their life cycles in micro-gravity. It was valid to ask whether important biological processes like cell-cycle regulation, gene regulation, embryology, and cell differentiation could work without gravity. The answer is in: they can.
  • Vestibular organs, bones, and muscles of larger mammals are affected by microgravity, but they are designed to sense or negotiate gravity so it's no surprise they're gravity-dependent. There is no evidence that studies of dysfunction in microgravity contributed to understanding how organisms function on Earth.

Where No One Has Gone Before

Among the loudest protests against ISS are those who are dedicated to opening the space frontier to human settlement as quickly as possible. And except in the most indirect, long-term way, giving as many people as possible access to space isn't among the stated goals of the ISS.

For example, in a September 1999 keynote address at the Space Frontier Conference VIII—Launching the Space Millennium , NASA Administrator Daniel Goldin said when station is in a steady operational phase NASA hopes to turn the keys over to an entrepreneur—to make the ISS a commercial venture—and the government will be just another ISS tenant and user. If the station isn't commercialized, after 10 years of operation a national review will determine whether it still meets NASA's research needs and the needs of its international partners and the private sector. If not, it'll be shut down and de-orbited.

This decade-long window is what the late Gerard O'Neill—a Princeton professor, author of The High Frontier: Human Colonies in Space (1977), and founder of the Space Studies Institute—called the leisurely pace that characterized an isolated, protected program funded by a government dominant in the world. In his Alternative Plan for US National Space Program , O'Neill said the time scale for substantial accomplishment (measured as substantial economic or scientific return) must be shortened to outrun today's fierce global competition. That means five years maximum, rather than 20 to 40 years, for a significant return on investment.

Of course, none of the entrepreneurs who make up the nation's growing commercial space enterprise, or those who are working to open the space frontier to human settlement (the Mars Society, the Space Frontier Foundation, ProSpace, Back to the Moon, the Planetary Society), will wait 10 years—or even five—for the ISS to prove itself. And the growing number of advocates for the private use of space have their own ideas about how best to get there; most of these, in contrast to the options available with ISS, include actually going .

Testifying in October 1998 before the subcommittee on Space and Aviation of the House Committee on Science, former astronaut Charles "Pete" Conrad Jr. said US strategic goals over the next 40 years in space should include fostering a commercial space industry, exploring the solar system, settling the solar system, and exploring the universe.

Achieving any of these goals requires cheap access to space—transportation to low Earth orbit that's easy to operate, reliable, and inexpensive. There's no inherent technical barrier to creating such a capability. In energy terms, once you're in low Earth orbit, you're halfway to anywhere else in the solar system. Once we can put people, supplies, equipment and cargo in Earth orbit more effectively than we do now, that will open space up in a way that hasn't been possible to date.

A corollary to cheap access to space is that a lot of money can be saved and time scales for all space activities drastically shortened by making maximum use of resources that are already at the top of Earth's gravity well—like the intense solar energy available everywhere in space except in planetary shadows, and the abundant oxygen, silicon, and metals available on the Moon's surface. Up to now, all the materials used in space have been lifted from the Earth's surface—the bottom of Earth's gravity well.

According to Gerard O'Neill, the ratio of a rocket's liftoff weight (mainly propellants) to final weight (the remaining upper-stage rocket plus payload) is typically 60 to 1 for weights lifted to geostationary orbit or an escape trajectory. Deducting vehicle structure, the useful payload is typically only about 1/100th of lift-off weight. In contrast, for a rocket lifting a pay-load to escape from the Moon, payload plus vehicle can be as much as 60% of lift-off weight, instead of less than 2%, as in lift from the Earth. The advantage for launch from the Moon is 35-fold. And because the Moon is in vacuum, efficient launch machines there could operate on solar electric power and wouldn't need rocket fuel to launch materials into space.

The Space Studies Institute advises launching out of Earth's gravity well only items that will bring a high payback—information, intelligence (computerized or in the human brain), and sophisticated tools—not materials (like oxygen) or heavy structures. That's the way we opened the new world of the Americas, and it's the only practical way to open the new world of space.

In that sense, according to former NASA historian Alex Roland, nanotechnology represents the future of space technology. With nanotechnology, computers and machines can be built virtually at the atomic level. That means a very small package could be launched from Earth and become a very powerful instrument in space—not just a passive scientific instrument receiving information, but a machine that can do work in space. If nano-technology proceeds at its current rate of progress, we will be able to send powerful instruments long distances at high rates of speed, and put very powerful instruments into low Earth orbit at a very slight cost. That has enormous commercial implications.

A Civilization of Spacefarers

Robert Zubrin is founder and president of the Mars Society and author of several books about human space exploration, including Mars Direct , The Case for Mars, and Entering Space . He believes the space enterprise is a vehicle for transforming humanity into a spacefaring civilization—one that will have a virtually infinite number of new worlds to explore and settle, starting with Mars.

Like any other off-world destination, Mars travel involves developing launch systems that reduce the cost of space access. This hasn't been easy and it won't happen overnight. But government agencies like NASA can help by aiding new entrepreneurial launch companies in several ways. One is by directly contracting to develop small reusable launch systems. That's the most direct way, and it's how existing launch systems were developed.

By directing such procurement to small and medium-sized companies that are not now fielding launch systems, NASA and other agencies can create more competitors and different kinds of systems. Other subsidies include credits and tax breaks on investments. The government also could open the payload manifest for major space projects like the space station, including cargo delivery, on a competitive basis and give contingent contracts to such companies for some payloads.

To create private-sector companies to supply the medium-and heavy-lift launchers needed to build and sustain human space settlements would require a large manifest open to commercial efforts. The government could best help by establishing an initiative to permanently establish a manned base on the Moon or Mars. Once a base was established on Mars, and a large cargo requirement opened to competition, we would see the development of large and inter-planetary launch systems.


Further Reading

Beall, Donald R., and Dick Zimmer. "At Issue:Should the Space Station Be Built? USA Today (June 9, 1993). Reprinted in CQ Researcher (Dec. 24, 1993): 1145.

Bergrun, Norman. "The International Space Station: A Momentous Cultural, Scientific, and Societal Undertaking." AIAA Bulletin/The Insider News (Sept. 1999): B18-22.

Burrows, William E. "Why Build a Space Station? Popular Science 252, no. 5 (May 1998 Special Issue): 65-69.

Caprara, Giovanni. Living in Space: From Science Fiction to the International Space Station. Buffalo, NY: Firefly Books Ltd., 2000.

Carroll, Michael, and Andrew Chaikin. "OurMan-Made Moons." Popular Science 252, no. 5 (May 1998 Special Issue): 101.

Ferris, Timothy. Life Beyond Earth. New York:Simon & Schuster, 2001.

Goldin, Daniel. "The International Space Station:Striding Toward the Future." Popular Science 252, no. 5 (May 1998 Special Issue): 11.

Heath, Erin. "The Greatest Show Off Earth." National Journal 33, no. 18 (May 5, 2001): 1336-37.

Heinlein, Robert. The Moon Is a Harsh Mistress. St. Martin's Press, 1997 reprint.

Kluger, Jeffrey. "Who Needs This?" Time 152, no. 21 (Nov. 23, 1998): 88-91.

Kraft, Christopher. Flight: My Life in Mission Control. New York: Dutton, 2001.

Proceedings of The Lunar Development Conference, Return To The Moon II, July 20-21, 2000, Caesar's Palace-Las Vegas, sponsored by the Space Frontier Foundation, Space Studies Institute, and The Moon Society. Available from The Space Frontier Foundation, $45. Orders, 1-800-78-SPACE, or .

Sagan, Carl. Pale Blue Dot: A Vision of the Human Future in Space. New York: Random House, 1994.

Stover, Dawn. "The International Space Station." Popular Science 252, no. 5 (May 1998 Special Issue): 48-54.

United States Advisory Committee on theFuture of the U.S. Space Program. Report of the Advisory Committee on the Future of the U.S. Space Program. Washington, D.C., National Aeronautics and Space Administration (distributed by the National Technical Information Service), December 1990.

Vizard, Frank. "ISS Isn't About Science." Popular Science 254, no. 1 (Feb. 1999): 73.

Zubrin, Robert. Entering Space: Creating a Spacefaring Civilization. J.P. Tarcher: 2000.



Study of the changes that an organism undergoes from its conception as a fertilized egg (ovum) to its emergence into the world at hatching or birth.


A flight path outward from a primary body calculated so a vehicle doesn't fall back to the body or orbit it.


A circular path 22,300 mi (35,900 km) above the Earth's equator on which a satellite takes 24 hours, moving from west to east, to complete an orbit, and so seems to hang stationary over one place on the Earth's surface.


An analogy in which the gravitational field is likened to a deep pit from which a space vehicle has to climb to escape the gravitational pull of a planetary body.


Radiation that knocks electrons from atoms during its passage, leaving positively or negatively charged ions in its path.


An orbit 93 to 186 mi (150 to 300 km) from Earth's surface.


Small gravity levels or low gravity.


Building devices on a molecular scale. The idea of manipulating material on a nanometer scale—atom by atom—was first discussed by physicist Richard Feynman in 1959.


The path that a comet, planet, or other satellite follows in its periodical revolution around a central body. For instance, the Earth follows an orbit around the Sun. The Moon revolves around the Earth. Now, an artificial "moon," the International Space Station, also circles the Earth.


Originally, the revenue-producing portion of an aircraft load—passengers, cargo, mail. By extension, that which a spacecraft carries over and above what is needed for its operation.


A condition in which a deep layer of soil doesn't thaw during the summer but stays below 32°F (0°C) for at least two years, even though the soil above it thaws. It gives rise to a poorly drained form of grassland called tundra.


A change in a feature that characterizes a system—like changes from solid to liquid or liquid to gas. Phase transitions can occur by changing variables like temperature and pressure.


An artificially constructed outpost in outer space in which humans can live and work without space suits. Salyut 1, history's first space station, was launched into orbit by the Soviet Union in April 1971.


The flow of a fluid in which the flow changes continually and irregularly in magnitude and direction. It's the opposite of streamline.

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Jan 9, 2010 @ 8:20 pm
i love the iss and i will be so happy to get info on it by email plz and thank you
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Feb 20, 2011 @ 5:05 am
Very interesting. I've heard about the controversies surrounding the ISS, but this article gives a very clear and broad review. Thanks :)

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