The Value of the Moon

by Paul D. Spudis

  Why is it important for the United States to make the Moon a high priority goal? Because the United States is not the only nation interested in it. This coin of international interest has two sides. On the positive side, our partners in current space endeavors, such as the International Space Station, have expressed great interest in human missions to the Moon. Some have begun the process of gathering detailed information from precursor robotic missions to enable future human missions to the Moon. How can we proclaim world leadership in space if we ignore a prominent destination that so many other nations are anxious to visit and exploit? Nations such as China have plans to explore and use the Moon with both robotic machines and with people. While their lunar intentions appear benign at present, they are developing capabilities now that could pose a threat to the security of this nation and other countries in the near future. Thus, there is a strategic dimension to American lunar presence. It is vital to the security and economic health of the community of nations that future societies in space develop according to pluralistic, democratic principles and that commerce is open to free markets, with respect for property rights and contract law. Although American presence in cislunar space does not guarantee such an outcome, our absence from this theater could well result in the reverse.

  What makes the Moon both important and unique? It is close, interesting, and useful. The close proximity of the Moon to Earth means that we can always and easily access it, unlike the limited and infrequent launch windows to all other planetary targets. This nearness means that much of the early preparatory work at the Moon can be done by robots on the lunar surface, as directed from Earth. Thus, the first humans to return to the Moon can arrive at a fully functional, turnkey lunar outpost, assembled in advance by these teleoperated robots. Interest in the Moon derives from its role as a small planet of complex and interesting process and evolution. The Moon’s environment permits unique and specialized scientific and engineering experiments to be conducted—studies not possible anywhere else in the solar system. We will find the answers to questions surrounding our moon’s complexity and gain a fuller understanding of our home planet’s early evolution. The utility of the Moon lies in its material and energy resources, the access to which will allow us to acquire the knowhow and means for humanity to plant its first foothold on another world.

  2

  The Moon Conquered—

  and Abandoned

  How is it that America went to the Moon, going from nearly zero space capability to the lunar surface in less than a decade, and then rapidly left it? Why have we not been back since? Within that tale are important lessons, some never fully absorbed by either historians or our national leadership. Millennia before we achieved it, humans dreamed about going to the Moon. The actual circumstances of our journey had not been imagined by science fiction authors and as a result, virtually all science fiction dealing with lunar travel made the first landing the beginning (not the end) of humanity’s movement into space. Now, it remains to be seen whether our first steps on the Moon really was an ending, or merely the prelude to a delayed golden age of spaceflight.

  Journeys to the Moon in Fiction and Fact

  The idea that some day we would be able to journey to the Moon is very old, conceivably going back as far as the early cave dwellers. The first literary description of trips to the Moon, Sun, and other heavenly destinations was likely the work of Lucian of Samosota (125–180 CE). Johannes Kepler, the discoverer of the laws of planetary motion, wrote Somnium (“Dream,” published posthumously by his son in 1634). In his novel, Kepler describes a trip to the Moon and the view of Earth and the solar system from its surface. English clergyman John Wilkins wrote several books about trips to the Moon, the most famous being The Discovery of a World in the Moone (1638). In it, he outlined the idea that someday people might inhabit the Moon. Included in Wilkins’s work were exotic and infeasible techniques on how to get there, such as transport by angels or with the help of harnessed fowl.

  During the Industrial Age, authors of classic science fiction took more reasonable (if still fanciful) approaches to the problem of lunar flight. In Jules Verne’s From the Earth to the Moon (1865), voyagers were shot from a huge cannon (the Columbiad) in order to reach escape velocity and land on the Moon. Verne skipped over how the acceleration from a cannon shot would create enormous g-forces that would kill his crew; he also misunderstood the nature of weightlessness by having his passengers experience it only when his moonship crossed the gravitational spheres of influence between Earth and Moon. Konstantin Tsiolkovsky, the inventor of astronautics and the first to derive the rocket equation, was inspired by Jules Verne and penned his own novel, On the Moon (1893). The character in Tsiolkovsky’s story wakes up on the Moon and experiences the unusual effects of being on an alien world. Curiously, considering his contributions to rocket science, Tsiolkovsky does not record the details of the trip from Earth. The approach of H. G. Wells was even more fantastic: A special substance called Cavorite (named for its inventor, a character in Wells’s 1901 novel First Men in the Moon) cuts off the force of gravity, allowing his sphere to effortlessly travel to the Moon. Once there, the voyagers find large insectlike creatures that live below the lunar surface.

  The Moon was lifted out of the realm of fiction and fantasy and put back into the domain of science with the advent of modern rocketry (an outgrowth of the Second World War). Starting with a few eccentrics, the Moon once again became a topic for scientific inquiry. Ralph Baldwin, an astronomy student at the University of Chicago, after noticing the spectacular series of telescopic photographs on display in the lobby of the Adler Planetarium, began cogitating about the origin of craters, basins, and the evolution of the lunar surface. He wrote down thoughts for a couple of articles before being pressed into war service, where he helped develop the proximity fuse. After the war, Baldwin collected his lunar ideas into a book, The Face of the Moon (1949).1 This pre–Space Age synthesis was a fairly complete and accurate account of the Moon’s processes and history—how the craters and basins were formed by impact, that the dark smooth maria were volcanic lava flows (Baldwin correctly identified them as basalt), and that the Moon’s surface was very old compared to that of Earth’s. Baldwin’s study of the Moon continued throughout his life, and he lived to see virtually all of his surmises validated through the exploration of the Moon by the Apollo missions.

  Shortly after this work appeared, the noted science fiction author Arthur C. Clarke published The Exploration of Space in 1951.2 Clarke outlined an expansive vision of the future, including rockets into Earth orbit, trips to the Moon, and voyages to the planets. Interestingly, he made some careful and prescient observations about the issues of landing and sustaining a permanent human presence on the Moon. Clarke considered the Moon an essential way station on the road to the planets. Here humans would learn the techniques of exploring and living on an alien world. Clarke specifically recognized that using the mineral resources of the Moon to support human presence and create new capabilities was essential. He pointed out that, at least in the early phases of operation, centralizing operations at a single site on the Moon would permit concentration of resources to maximize capabilities quickly. Thus, Clarke advocated building a base, not multiple sortie missions to many different locations. After the establishment of a presence at a base, we would be able to explore the entire Moon at our leisure.

  Accounts hold that Nobel Prize–winning chemist Harold Urey became engrossed by The Face of the Moon when, by chance, he picked up the book at a party. Baldwin’s description of the lunar landscape and the impact origin of its craters convinced Urey that the primitive, ancient Moon held secrets to the origin of the solar system. He went on to lead an effort that applied the basic principles of chemistry and physics to the origin and evolution of the Moon and planets.3 Another astronomer, Gerard Kuiper, held the “heretical” view that the Moon and the planets were worthy objects for observation and scientific study. For further study and mapping, he collected the
best telescopic images of the Moon at the Lunar and Planetary Laboratory that he established in 1960 at the University of Arizona in Tucson. Geologist Eugene Shoemaker, who was mapping uranium deposits in northern Arizona for the US Geological Survey in the 1950s, decided to reexamine the geology of Coon Butte, the feature dismissed by G. K. Gilbert as not being an impact structure sixty years earlier. Using the geology of the crater to unravel the mechanics of hypervelocity impact, including the discovery of forms of silica created only under extremely high pressures, Shoemaker decided that Coon Butte was an impact crater. It has been known as Meteor Crater ever since.4

  But Gene Shoemaker did more than just document the impact origin of Meteor Crater. In 1960, he made the first geological map of the lunar surface, showing the basic sequence of events that had occurred there. In brief, this technique involves using overlap and superposition relations to classify laterally continuous rock units, including sheets of crater ejecta and lava flows. These properties can be determined directly from visual observations and photographs. Shoemaker mapped the region near the crater Copernicus on the near side, working out the basic framework of lunar stratigraphy—that is, the sequence of layered rocks.5 He then used this information to estimate the time correlation between events on the Moon and those on Earth, concluding that the Moon preserved an ancient surficial record, which holds part of the early geological story missing from the eroded and dynamic surface of Earth.

  These scientists and their research, each in their own way, made the study of the Moon and its processes scientifically respectable. After the launch of the first Earth-orbiting satellite Sputnik 1 in October 1957, it was reasonable to imagine that spacecraft might be sent to the Moon. Soon, observations of the Moon’s surface through telescopes, the mapping of terrestrial impact craters, and compositional studies of rocks from terrestrial impact craters and meteorites (rocks from space) became part of cutting-edge lunar science. A gradual but perceptible momentum began to formulate a conceptual model that would allow us to explore the Moon effectively and give us an understanding of its history. Some dreamed that they might live to see people travel to the Moon in their lifetimes (and Shoemaker planned on being one of them). Shoemaker’s dream would come true in part, but under circumstances that no one foresaw.

  The Apollo Program

  In a series of articles published in Collier’s in the 1950s, rocket scientist Wernher von Braun outlined a plan to send people to the Moon and to Mars.6 Accompanied with colorful illustrations by space artists such as Chesley Bonestell, von Braun’s articles caught the imagination of the public, including a very imaginative Walt Disney, who went on to feature von Braun’s ideas in a series of programs as part of his new television series Disneyland (1954). Viewers were treated to a four-program series outlining the basic von Braun architecture: rocket to Earth orbit, space station, Moon tug, and human Mars spacecraft. This steppingstone approach made both logical and programmatic sense. Each piece enabled and supported the next step into space. Although some technical details in von Braun’s plan were out of date before they were realized—for example, von Braun had electrical power in space generated by solar thermal power alternately vaporizing and condensing mercury to drive turbines, a technology made obsolete with the advent of solar photovoltaic cells—major parts of his scheme enabled the establishment of a robust and permanent spacefaring system.

  However, international events soon intervened on von Braun’s orderly approach. The advent of the Apollo program altered what was to have been a logical, incremental, and thoughtful space plan into a race once competition with the Soviet Union became our overriding concern. The slow approach had to be accelerated once President Kennedy committed the nation to a decadal deadline. Under ordinary technical development, each piece would be designed, built, flown, and modified according to its performance. But with scheduling pressure designed to beat the Soviets to the Moon, a much faster approach was required. This caused von Braun and others at the newly created National Aeronautics and Space Administration (NASA) to reexamine the problem of sending people to the Moon. Did we really need a space station first? Or was it possible to build a launch vehicle big enough to send an entire expedition to the Moon in one fell swoop?

  Although the space agency had already begun planning for the development of a new super heavy lift rocket and had done some preliminary studies of manned missions to the Moon, the announcement of a lunar landing goal by President John F. Kennedy in May 1961 shocked many at NASA. It was one thing to daydream about sending people into deep space and to the Moon, but quite another to actually be given the task to do so—and then bring them back safely to Earth, a stipulation of Kennedy’s declaration. When the commitment to go to the Moon was made, the total manned spaceflight experience of the United States consisted of Alan Shepard’s fifteen-minute-long suborbital hop. A lunar voyage would require the mastery of a variety of complex spacefaring skills, including precision navigation and maneuvers necessary to change orbit in flight.

  The design or “architecture” for a manned lunar mission was debated extensively before the “mode decision.” Initial plans called for either a direct ascent to the lunar surface or a rendezvous of two launched spacecraft in Earth orbit. Both approaches called for the development of a “super” heavy lift launch vehicle, Nova, a rocket capable of launching up to 180 metric tons to low Earth orbit.7 John Houbolt, an engineer at Langley, advocated instead for something called lunar orbit rendezvous.8 This called for a small vehicle that would land on the lunar surface, then return to rendezvous with the Apollo spacecraft that had remained in orbit around the Moon. Although this mission profile was thought to be very risky (a rendezvous had never been accomplished in space, let alone one involving two separate spacecraft orbiting the Moon), it did enable the voyage to be launched “all up” on a single heavy lift rocket. This design became the Saturn V, a rocket capable of launching 127 metric tons to low Earth orbit.

  With the principal design features of Apollo outlined, the American space program next undertook a series of manned and unmanned missions in preparation for a lunar landing. While human missions practiced specific techniques (including rendezvous and docking), robotic missions gathered information about the Moon’s surface conditions and environment and sought to identify a smooth, safe landing site. In preparation for the Moon, we flew six single-man Mercury missions, ten two-man Gemini missions, and four three-man Apollo rehearsal flights. There were thirteen successful robotic precursor missions to the Moon: three hard-landers, five soft-landers, and five orbiters. All this occurred within the eight years between Kennedy’s speech and the landing of Apollo 11, a span of time that included the assassination of President Kennedy on November 22, 1963, and a twenty-two-month stand-down after the tragic fire on Apollo 1 of January 27, 1967, which killed astronauts Virgil “Gus” Grissom, Ed White, and Roger Chaffee.

  The Apollo spacecraft was extensively redesigned and modified after the Apollo 1 fire. Following a highly successful checkout of the newly refurbished Command-Service Modules in Earth orbit on Apollo 7, an eleven-day mission in October 1968, the planned journey of Apollo 8 to orbit the Moon seemed to be a bold, even reckless move. After all, a spacecraft sent to the Moon without any rescue capability using a lunar module (LM) could have ended in tragedy, as was demonstrated a few years later during the Apollo 13 mission. We now know that there was a reason, one that was withheld from the public at the time, for sending Apollo 8 on a lunar journey. The CIA had intelligence that the Soviets were planning a manned flight around the Moon by the end of 1968. They had just completed a circumlunar mission with their unmanned Zond 8, which demonstrated that the pieces for such a flight were ready. It was believed, probably correctly, that if the Soviets were able to pull this off, they would then claim to have won the Moon race, making an actual lunar landing irrelevant.9 This possibility lent urgency to flying a manned lunar mission as soon as possible, even one that simply orbited, rather than landed on, the Moon. So, just before Chris
tmas in 1968, Apollo 8 orbited the Moon carrying Frank Borman, Jim Lovell, and Bill Anders. Although it was not evident at the time, the flight of Apollo 8 effectively won the Moon race for the United States.

  The next two missions qualified the Apollo lunar module in Earth orbit and in lunar orbit. Then, on July 20, 1969, Apollo 11 landed two men on the Moon. There were a few heart-stopping moments when the ship’s computer sent the Apollo 11 LM Eagle toward a large, block-strewn lunar crater, but astronauts Neil Armstrong and Buzz Aldrin successfully overrode the automatic system and landed safely. Initial concerns about possible dangerous surface conditions were soon dispelled as the crew conducted a successful 2.5-hour exploration of their immediate landing site. They collected rock and soil samples, laid out experiments, and verified that the surface was both strong enough to support the considerable mass of the LM as well as other equipment. The world watched as they demonstrated what it was like to move around on the Moon in one-sixth the gravity of Earth. Armstrong made an unreported traverse to a blocky crater that he had flown over during his landing approach and observed the bedrock in the crater floor. Twenty-two hours later, the two-man crew blasted off the Moon’s surface to rendezvous with Mike Collins, orbiting the Moon in the Command Module Columbia. With the crew’s safe return to Earth a few days later, Kennedy’s daring challenge to America eight years earlier was fulfilled.