Expedition Mars Martin J.L. Turner Praxis/Springer-Verlag, New York, 2004. $39.95 (321 pp.). ISBN 1-85233-735-4
We astronomers and astrophysicists have engaged in the Mars argument at one time or another with our colleagues and our nontechnical friends. Should the US, with or without the cooperation of other nations, commit the resources to send humans to Mars and return them to Earth in the next few decades? In Expedition Mars , Martin Turner, a principal research fellow in the department of physics and astronomy at the University of Leicester in the UK, makes the case for the human exploration of Mars by providing historical background, describing the current state of spaceflight technology relevant to a Mars mission, and discussing the arguments for human space exploration. I have to say that while I appreciated the historical and technical discussions and personally support human space exploration, I didn’t find Turner’s arguments especially compelling.
I enjoyed the historical descriptions of the contributions of the early rocket pioneers Konstantin Tsiolkovsky, Robert Goddard, and Wernher von Braun, as well as the American and Russian manned programs. Military considerations clearly drove the political systems to support the scientific and engineering programs that built the V2 and the Saturn 5 boosters and put men on the Moon. They also drove the development of propulsion systems other than chemical rockets. These fascinating stories are not well known. Electric- and nuclear-powered rockets may contribute to future long-duration missions, and the book does a nice job of outlining their history and current status.
Expedition Mars does not follow a straight path through the material. The book starts with an executive summary of sorts that recaps the Apollo program, gives a brief description of Mars, and outlines the available technology and the political argument for human exploration. Next are a chapter recounting the World War II German program and von Braun’s proposed “Marsprojekt”; a chapter on the orbital mechanics and the challenges involved in getting from Earth to Mars, landing on the surface of the planet, and returning home; three chapters that summarize chemical-, electric-, and fission-powered propulsion technologies; and a recap of proposals to use Mars materials to make fuel for the return flight. The final two chapters synthesize Mars proposals from the recent past—President George H. W. Bush’s Space Exploration Initiative and NASA’s Mars Reference Mission developed at the Johnson Space Center in 1997 and 1998—and summarize the technical and political hurdles to placing humans on Mars.
The book is aimed at the science-literate public, although the material varies in level of detail. The use of equations to illustrate points is not pitched at a useful level—not enough development for typical physics undergraduates and too much detail for the lay public or the professional. Some of the descriptions of the underlying science, such as the Hall effect as it pertains to electric thrusters, fall in this nether region between novices and experts.
Turner makes a believable case for our global technological capacity and does not shy away from acknowledging, if not resolving, potential political problems. For example, building and placing nuclear reactors in space to power the Mars transfer and return vehicles seem like technically desirable approaches. Whether the White House, Congress, or the public will embrace such a plan without a significant and as yet undefined motivator (such as World War II or the cold war) is doubtful. As an example of a political hurdle, Turner points out that researchers in the space-science community generally do not support the human-exploration program because they effectively use much more economical unmanned platforms for their work. Such lack of support from the space-science community leaves the aerospace industry and space-related government agencies as the primary advocates for the program. Turner also argues that with a 20-year price tag between $55 billion for the Mars Reference Mission and $450 billion for the Space Exploration Initiative, it is difficult to imagine that, in the current budget climate, Congress will authorize the funds. One can already see the evidence for that idea in Congress’s tepid response to President George W. Bush’s recent and more modest exploration initiative.
Turner’s case for going to Mars, though basically sound, fails the political-imperative test. No matter how eloquently one expresses the most compelling argument I know, that the long-term return on investment in exploration—whether in space, the Superconducting Super Collider, or the biology laboratory—always exceeds any other initiative to improve the human condition, that argument alone is not enough. By itself, it cannot incite action from a society fully engaged with short-term issues. Von Braun’s genius was the ability to tie his vision to the reality of the times.
Once, during the days when I was a NASA astronaut, I naively dared to dream that I might get to fly to Mars. Times are different today. Now, I hope to live long enough to experience the voyage to Mars vicariously. At least Expedition Mars helps show how it might be done.
George D. Nelson is a professor of physics and astronomy and director of science, mathematics, and technology education at Western Washington University in Bellingham. He was a NASA astronaut from 1978 to 1989.
