The Space Reviewin association with SpaceNews

ISS illustration
The ISS has been the focal point of countless debates about its utility; just how well has the station met the goals laid out for it over the years? (credit: NASA)

Twenty-five gigabucks of steel: the objectives of the International Space Station

<< page 1: conducting materials research

Serving as a construction platform for Lunar and Mars missions

During the 1980s the space station was touted by NASA as a potential spaceport for launching human planetary missions. Although no human planetary missions were approved at that time, substantial amounts of money were spent on redesigning the station in order to make it capable of supporting this objective by equipping it with construction and refueling equipment and a spacecraft hangar. However, because these designs were abandoned at a rather early stage in station development, it is not fair to declare that the space station has failed to meet this goal.

Supporting ex-Soviet aerospace workers and institutions, and symbolizing post-Cold War US-Russian cooperation

The purpose of the space station was fundamentally transformed in the early 1990s to serve new goals. When Bill Clinton became President in January 1993, the space station had barely survived several close votes in Congress and serious attempts to kill it. The new president and his staff were clearly unconvinced that the then-stated goal of serving as a biological and materials research laboratory in orbit justified the immense costs. NASA Administrator Dan Goldin then found a new mission for the station: supporting ex-Soviet aerospace workers and serving as a symbol of cooperation between two former adversaries.

The ISS has had little or no success at improving relations between the two countries in non-space areas, but the ability of space projects to lead other cooperation has always been limited.

Goldin argued that without material support, aerospace workers, particularly those near Moscow, would no longer support Russian President Boris Yeltsin, who was then viewed as an important democratizing force for Russia. Even worse, many of them would leave their country to work on missile programs in Iran, Iraq, Libya, and elsewhere. The space station thus became both a stabilizing project and an anti-proliferation project. In addition, Goldin made the space station a symbol of the post-Cold War world. He convinced Clinton to ask the Russians to join the space station program.

Although it is hard to quantify these goals, this effort has been a substantive success. Although some ex-Soviet aerospace workers clearly went to other countries to work on missile programs, most did not. Yeltsin was not overthrown, and the Soviet political structure remained stable throughout the 1990s.

Despite constant friction, both the United States and Russia have remained partners. The space station has been an important symbol of cooperation. Arguably, it has had little or no success at improving relations between the two countries in non-space areas, but the ability of space projects to lead other cooperation has always been limited.

Finally, it should be noted that this cooperation was supposed to have other benefits. It was to both reduce the cost of the space station and to give the United States access to substantial Soviet/Russian spaceflight experience. It has failed to do the former, but obviously has achieved the latter. Without Russian cooperation, the United States would either have had to develop an alternative method of reaching the space station, or would have faced being unable to reach it when the space shuttle was grounded.

Learning how to construct large structures in space

It is possible to argue that the space station never needed to be as big and as complex as it currently is. After all, the Soviet Union had decades of experience launching space stations that were operational as soon as they achieved orbit. The American-led space station program was as big and complicated (and expensive) as it is primarily not because of any scientific objectives, but because NASA is an engineering agency that inherently designs each new construction project to be more complex and challenging than the last one.

Nevertheless, future space objectives such as sending humans to Mars will require substantial construction in space, and the ISS has provided a learning experience for these future as yet unapproved projects. NASA rarely states in print that gaining large-scale construction experience is an objective of the ISS, but agency officials have declared in speeches and public talks that this is one “benefit” of the project.

It is possible to argue that the space station never needed to be as big and as complex as it currently is.

Certainly by some measures the agency has gained this experience, and therefore the space station can be considered a success. Whether or not that knowledge and experience is sufficient, or will be retained by the time that the next major project is undertaken, is unknown.

Learning how to operate in space

The space station was intended to provide experience on how to live and work in space. It has clearly provided this. In fact, at various times during its planning stage there were warnings about the large number of EVAs required for station assembly. Although the number of EVAs required was reduced, the United States has still conducted more of them for space station assembly than in all its previous space operations, developing new techniques and proving that they can be conducted safely and effectively.

Engineering testbed for space equipment

A relatively recent justification for the space station has been its role in serving as a testbed for equipment for use in future human and even robotic space missions. NASA is currently planning on flying advanced batteries and some other equipment on the space station that offer potential for improving future missions. Although this has not happened yet, it will soon, apparently even before the ISS construction is declared complete. Although the verdict is out, the space station should be able to serve successfully in some capacity as an engineering testbed. Of course, this does not mean that it is ideal for this purpose, and it certainly does not mean that it is economical, but the ability to have humans monitor equipment mounted either inside or outside the station does appear to have certain attractions.

Conducting human biological research to support future long-duration space missions

This objective has long been advanced as one of the values of a space station, but NASA has tended to keep this goal muted for the same reason that it has not often touted many other justifications for the space station—the program needed to justify itself, not some other unapproved, costly, and inevitably controversial future mission. Such justifications also undercut the claim that the station could serve needs on Earth, such as pharmaceutical research.

Success is irrelevant if the goals are not considered worthwhile.

Rather ironically, this tenuous justification is also one of the most logical. Despite decades of flying humans in space, our ignorance of its effects outweighs our knowledge, particularly in the area of long-duration spaceflight. For instance, we know that human physiology deteriorates in microgravity. Bones lose calcium, for example, among the many long- and short-term effects that can be observed. What is lacking is an understanding of how these effects can be eliminated, mitigated, or corrected. For instance, at what point is gravity sufficient that these effects are no longer present? Is it one-tenth Earth gravity, one-sixth (such as experienced on the Moon), or higher? This information is vital for future missions and could even determine whether or not they happen. For instance, if even Martian gravity (just over one-third Earth gravity) causes severe physiological degradation, then, human missions to Mars could be highly risky.

This justification has now become one of the primary research objectives of the space station under the Vision for Space Exploration. With NASA officially directed to pursue the goal of returning humans to the Moon and eventually sending them to Mars, the space station’s research agenda is being modified to support this goal. However, the new NASA administrator has indicated that this research agenda may be postponed in order to pay for near-term costs.

Pork barrel politics

Although no politician is ever so blunt, it is clear that pork barrel politics—delivering money to industry and constituents in key congressional districts—has long been an important purpose of the space station program. Often this objective is clearly stated by supporters, although usually in terms of supporting American aerospace industry, or in terms of preventing losses of existing contracts. This is simply a matter of the way politics is conducted, and the space station program has been successful in bringing money to important political and economic constituencies.

Success, failure, and priorities

While this analysis has demonstrated that success and failure are subjective, it has also highlighted that a more important issue is the importance of the goals and justifications, and whether or not there is a consensus about them. Success is irrelevant if the goals are not considered worthwhile.