Is Human Spaceflight Obsolete?

During the past year, there has been a painstaking, and painful, investigation of the tragic loss of the space shuttle Columbia and its seven crew members on February 1, 2003. The investigation focused on technical and managerial failure modes and on remedial measures. The National Aeronautics and Space Administration (NASA) has responded by suspending further flights of its three remaining shuttles for at least two years while it develops the recommended modifications and procedures for improving their safety.

Meanwhile, on January 14, 2004, President Bush proposed a far more costly and far more hazardous program to resume the flight of astronauts to and from the Moon, beginning as soon as 2015, and to push forward with the development of “human missions to Mars and the worlds beyond.” This proposal is now under consideration by congressional committees.

My position is that it is high time for a calm debate on more fundamental questions. Does human spaceflight continue to serve a compelling cultural purpose and/or our national interest? Or does human spaceflight simply have a life of its own, without a realistic objective that is remotely commensurate with its costs? Or, indeed, is human spaceflight now obsolete?

I am among the most durable and passionate participants in the scientific exploration of the solar system, and I am a long-time advocate of the application of space technology to civil and military purposes of direct benefit to life on Earth and to our national security. Also, I am an unqualified admirer of the courageous individuals who undertake perilous missions in space and of the highly competent engineers, scientists, and technicians who make such missions possible.

Human spaceflight spans an epoch of more than forty years, 1961 to 2004, surely a long enough period to permit thoughtful assessment. Few people doubt that the Apollo missions to the Moon as well as the precursory Mercury and Gemini missions not only had a valuable role for the United States in its Cold War with the Soviet Union but also lifted the spirits of humankind. In addition, the returned samples of lunar surface material fueled important scientific discoveries.

But the follow-on space shuttle program has fallen far short of the Apollo program in its appeal to human aspirations. The launching of the Hubble Space Telescope and the subsequent repair and servicing missions by skilled crews are highlights of the shuttle’s service to science. Shuttles have also been used to launch other large scientific spacecraft, even though such launches did not require a human crew on a launching vehicle. Otherwise, the shuttle’s contribution to science has been modest, and its contribution to utilitarian applications of space technology has been insignificant.

Almost all of the space program’s important advances in scientific knowledge have been accomplished by hundreds of robotic spacecraft in orbit about Earth and on missions to the distant planets Mercury, Venus, Mars, Jupiter, Saturn, Uranus, and Neptune. Robotic exploration of the planets and their satellites as well as of comets and asteroids has truly revolutionized our knowledge of the solar system. Observations of the Sun are providing fresh understanding of the physical dynamics of our star, the ultimate sustainer of life on Earth. And the great astronomical observatories are yielding unprecedented contributions to cosmology. All of these advances serve basic human curiosity and an appreciation of our place in the universe. I believe that such undertakings will continue to enjoy public enthusiasm and support. Current evidence for this belief is the widespread interest in the images and inferences from the Hubble Space Telescope, from the new Spitzer Space Telescope, and from the intrepid Mars rovers Spirit and Opportunity.

In our daily lives, we enjoy the pervasive benefits of long-lived robotic spacecraft that provide high-capacity worldwide telecommunications; reconnaissance of Earth’s solid surface and oceans, with far-reaching cultural and environmental implications; much-improved weather and climatic forecasts; improved knowledge about the terrestrial effects of the Sun’s radiations; a revolutionary new global navigational system for all manner of aircraft and many other uses both civil and military; and the science of Earth itself as a sustainable abode of life. These robotic programs, both commercial and governmental, are and will continue to be the hard core of our national commitment to the application of space technology to modern life and to our national security.

The human touch

Nonetheless, advocates of human spaceflight defy reality and struggle to recapture the level of public support that was induced temporarily by the Cold War. The push for Mars exploration began in the early 1950s with lavishly illustrated articles in popular magazines and a detailed engineering study by renowned rocket scientist Werner von Braun. What was missing then, and is still missing today, is a compelling rationale for such an undertaking.

Early in his first term in office, President Nixon directed NASA to develop a space transportation system, a “fleet” of space shuttles, for the transport of passengers and cargo into low Earth orbit and, in due course, for the assembly and servicing of a space station. He declared that these shuttles would “transform the space frontier of the 1970s to familiar territory, easily accessible for human endeavor in the 1980s and 1990s.” Advocates of the shuttle assured the president and the Congress that there would be about one shuttle flight per week and that the cost of delivering payloads into low Earth orbit would be reduced to about $100 per pound. They also promised that the reusable shuttles would totally supplant expendable unmanned launch vehicles for all purposes, civil and military.

Fast forward to 2004. There have been more than 100 successful flights of space shuttles–a noteworthy achievement of aerospace engineering. But at a typical annual rate of five such flights, each flight costs at least $400 million, and the cost of delivering payloads into low Earth orbit remains at or greater than $10,000 per pound–a dramatic failure by a factor of 100 from the original assurances. Meanwhile, the Department of Defense has abandoned the use of shuttles for launching military spacecraft, as have all commercial users of space technology and most of the elements of NASA itself.

In his State of the Union address in January 1984, President Reagan called for the development of an orbiting space station at a cost of $8 billion: “We can follow our dreams to distant stars, living and working in space for peaceful, economic, and scientific gain. . . . A space station will permit quantum leaps in our research in science, communications, in metals, and in lifesaving medicines which could be manufactured only in space.” He continued with remarks on the enormous potential of a space station for commerce in space. A year later he reiterated his enthusiasm for space as the “next frontier” and emphasized “man’s permanent presence in space” and the bright prospects for manufacturing large quantities of new medicines for curing disease and extraordinary crystals for revolutionizing electronics–all in the proposed space station.

Again, fast forward to 2004. The still only partially assembled International Space Station has already cost some $30 billion. If it is actually completed by 2010, after a total lapse of 26 years, the cumulative cost will be at least $80 billion, and the exuberant hopes for its important commercial and scientific achievements will have been all but abandoned.

The visions of the 1970s and 1980s look more like delusions in today’s reality. The promise of a spacefaring world with numerous commercial, military, and scientific activities by human occupants of an orbiting spacecraft is now represented by a total of two persons in space–both in the partially assembled International Space Station–who have barely enough time to manage the station, never mind conduct any significant research. After observing more than 40 years of human spaceflight, I find it difficult to sustain the vision of rapid progress toward a spacefaring civilization. By way of contrast, 612,000,000 revenue-paying passengers boarded commercial aircraft in the year 2002 in the United States alone.

In July 1989, the first President Bush announced his strategy for space: First, complete the space station Freedom (later renamed the International Space Station); next, back to the Moon, this time to stay; and then a journey to Mars–all with human crews. The staff at NASA’s Johnson Space Center dutifully undertook technical assessment of this proposal and published its Report on the 90-Day Study of Human Exploration of the Moon and Mars. But neither Congress nor the general public embraced the program, expertly estimated to cost some $400 billion, and it disappeared with scarcely a trace.

Drawing lessons

The foregoing summary of unfulfilled visions by successive presidents provides the basis for my skepticism about the future of the current president’s January 14, 2004, proposal; a kind of echo of his father’s 1989 proposal. Indeed, in 2004, there seems to be a much lower level of public support for such an undertaking than there was 15 years ago.

In a dispassionate comparison of the relative values of human and robotic spaceflight, the only surviving motivation for continuing human spaceflight is the ideology of adventure. But only a tiny number of Earth’s six billion inhabitants are direct participants. For the rest of us, the adventure is vicarious and akin to that of watching a science fiction movie. At the end of the day, I ask myself whether the huge national commitment of technical talent to human spaceflight and the ever-present potential for the loss of precious human life are really justifiable.

In his book Race to the Stratosphere: Manned Scientific Ballooning in America (Springer-Verlag, New York, 1989), David H. De Vorkin describes the glowing expectations for high-altitude piloted balloon flights in the 1930s. But it soon became clear that such endeavors had little scientific merit. At the present time, unmanned high-altitude balloons continue to provide valuable service to science. But piloted ballooning has survived only as an adventurous sport. There is a striking resemblance here to the history of human spaceflight.

Have we now reached the point where human spaceflight is also obsolete? I submit this question for thoughtful consideration. Let us not obfuscate the issue with false analogies to Christopher Columbus, Ferdinand Magellan, and Lewis and Clark, or with visions of establishing a pleasant tourist resort on the planet Mars.