Just how full of opportunity is the Moon?
by Donald A. Beattie
|Proposing a grand “Vision” to explore our solar system has value; however, what the pace and emphasis should be needs to be continually debated based on evolving national needs and the ability to find required resources.|
There is no question that it would be possible to build human settlements on the Moon. Such a program was proposed in the late 1960s when all of the infrastructure was in place and paid for, but it was denied by Congress and the Nixon administration. A Space Exploration Initiative that included returning to the Moon, similar to the program currently underway, was unveiled by President George H.W. Bush in 1989. It was also denied by Congress. There were no compelling reasons then, and there are none now, to spend a major fraction of the nation’s space budget to return humans or robots to the Moon. Some claim that the theme of human settlement will be important as it supports the goals of all the other themes. That may be true, but its importance is doubtful because it places a high value on very questionable objectives as discussed below.
Human missions to Mars, if and when they might occur, are so far in the future that lessons learned on the Moon will have little relevance. If humans eventually travel to Mars, technology that would be used will be far advanced over that which NASA would employ on the Moon in the next twenty years. The first humans who might travel to Mars will probably not have the immediate objective of establishing a settlement. Rather, they will go as explorers and spend only that amount of time required to meet initial objectives, with their staytime defined by orbital mechanics. Determining how to utilize lunar resources to supply a lunar base will not have applicability to a Mars base as the technology and processes needed to use Mars raw materials will be unique to Mars resources. Other surface conditions on Mars that human explorers will have to cope with will also be much different than those found on the Moon and will require specific technology to ensure safe operations. Costly and risky human exploration of Mars may never be needed. As robots become more capable, the major scientific and philosophical question that drives Mars exploration—does life exist or has it ever existed on Mars—may well be answered by robotic missions. The need to establish human settlements on Mars in the future is problematic.
Scientific investigations, discussed in the recent National Research Council (NRC) report “The Scientific Context for Exploration of the Moon” define an extensive exploration program. If pursued, the program would add additional information to our present knowledge of the Moon’s early history and current state. However, we already have an excellent understanding of the Moon’s history and composition compiled from data returned from Surveyor, Lunar Orbiter, and Apollo missions. The more recent Clementine and Lunar Prospector missions also contributed to our understanding. Added detail is only of interest to those who have spent most or all of their professional lives studying the Moon. It is unlikely that any new information collected during detailed lunar exploration will resolve fundamental questions being asked regarding the origin and evolution of the solar system. Making this theme even more suspect in terms of its importance, a successful implementation of NRC program would require numerous robotic missions complimented by many human missions. The robotic missions would have to be more capable than the present Mars rover missions for, in addition to making detailed chemical and mineralogical measurements, many would require deep drilling and sample return from both the Moon’s near and far sides. To date, there have been no estimates of how much such an ambitious campaign would cost. NASA has dodged the question of cost for both robotic and human missions, including establishing human settlements, by hiding behind the slogan that returning to the Moon is based on an “open architecture.” Or in other words, to defuse the critics, it is whatever you want it to be. Not a very strong position on which to ask the Congress to commit to spending huge sums.
There are no lunar resources that, when processed, would have any economic value if utilized on the Moon or returned to Earth. Lunar in situ resource utilization has been shown by several analyses to not have a positive cost benefit. Enthusiasts who have made claims to the contrary have done so by using questionable and very optimistic projections of what would be required. They would be well advised to reopen their chemistry and physics textbooks and spend some time with real-world mining and drilling operations.
|There are no lunar resources that, when processed, would have any economic value if utilized on the Moon or returned to Earth.|
A case in point is the assumption that water ice will be found at the lunar poles and could be mined to supply a base and other activities. (See “Ice on the Moon”, The Space Review, November 6, 2006) Based on measurements of the Moon’s polar regions made during the Lunar Prospector mission, some believe that large quantities of water ice will be found in permanently shadowed lunar craters. It should be remembered that Lunar Prospector did not record the presence of water ice, only an indication of “excess” hydrogen that some infer means water ice. If water ice exists, large amounts of lunar soil would have to be processed in the shadow of rock-strewn crater walls in order to recover sufficient quantities of oxygen and hydrogen to be used for either fuel or life support. Recent studies (Campbell et al., Nature, October 19. 2006) using the Arecibo radar to examine the Moon’s south polar region at much higher resolution than Lunar Prospector (20 meters per pixel vs. 40 kilometers), cast doubt on the probability that large amounts of water ice exist in such craters. Also, analyses have been made of what would happen if a comet, traveling at high speed, hit the Moon. They indicate that it is unlikely that much, if any, water released by the impact of a comet at low lunar latitudes would be transported and trapped in polar locations; it would instead evaporate into space. Only impacts of water-rich comets at high lunar latitudes would provide a chance to deposit water ice in the lunar regolith of permanently shadowed polar craters. In view of the above, the presence of water ice and the amount that might be found as a percentage of the lunar soil in permanently shadowed craters remains highly speculative. To base a program to build a settlement at the Moon’s south pole on such scanty evidence, and the requirement to employ highly questionable resource recovery, should not be considered.
Recent press releases seem to indicate that international interest in cooperating with NASA on returning humans to the Moon does not exist. Some, such as the British, have clearly indicated they have other plans. Based on statements made by NASA it would appear that in order for the initiative to return to the Moon to be successful, international cooperation will be required. A meeting has been announced in the spring to explore the interests of the international space community in joining the Vision. How many nations may sign up is problematic, with good reason, considering how the ISS international partners have been treated in the past. Meanwhile, some are leapfrogging ahead to send missions to Mars, the indisputable scientific prize. ESA’s ExoMars rover will be able to drill two meters into the Martian soil to look for signs of life and Russia is planning sample return from the moons of Mars. Some nations will undoubtedly send robotic missions to the Moon in the future. That will allow them to catch up, technologically, with the programs we successfully ran some forty years ago. However, it will be surprising if such missions will add significantly toward understanding our closest planetary neighbor.
Depending on the poll, and how the poll was conducted, support for NASA’s programs is usually high. However, most polls indicate that the “general public” knows few details about NASA’s programs and the size of its budgets that use their tax dollars. Interest among the young in our space program, in general, appears to be especially low, and when questioned about returning to the Moon show little enthusiasm about the program.
NASA’s 2005 authorization indicated that a majority in the 109th Congress supported the Vision. But the full impact on other NASA programs of that support had not been (and still has not been) fully defined and seems to be a moving target as NASA scrambles to fund contracted commitments. The 110th Congress will confront many problems, old and new, and has indicated that science programs will have to compete with other high-priority programs in future budgets. It will require many congresses and administrations to agree to fulfill the goals of the Vision. Further complicating this issue, Congress must decide how to prioritize all of the programs contained in NASA budgets to assure future benefits for the country from NASA research. Should a large percentage of NASA’s budget be spent on a single objective—returning to the Moon—that has little scientific value and no real economic benefits other than job creation? The fear among critics is that the current goal to return to the Moon is not sustainable under projected budgets. In the meantime, to support this goal, traditional NASA programs are being canceled or severely cut back. A recent example, among many, is the reduction in funding for Earth observation programs. Grandiose promises, with little substance to back them up, must be carefully examined. The Vision that NASA is following has not undergone such a careful examination.