Why the Moon?

We dream about man on the moon. The moon may seem dull and unattractive to visit. However, going to the moon is smart, and smart is sexy. A human presence on the moon is an essential stepping stone to Mars and the rest of the Solar System. Initially, as we crawl out of our cradle, we must use our closest neighbor as a playground to develop our space-faring skills. The strategy roadmap for the exploration of the Moon is displayed on the next page.

Returning to the Moon pursues three major goals:

• Exploitation of extraterrestrial resources for supporting the construction of human settlement infrastructures.
   
• Studying the Moon from its surface will help us to better understand the Solar System's formation. Moreover, the Moon is an ideal platform for space physical science studies and astronomy.
   
• Understanding human behavior in space before longer and more ambitious human missions are undertaken. Aspects related to physiology, psychology, and working in space can be more readily investigated using long duration Moon outposts.

Furthermore, due to the progressive nature of infrastructure development within our Step-by-step strategy, all of these points necessitate a human presence.

In terms of energy requirements, the Moon offers more affordable access to the rest of the Solar System than do most other celestial bodies with the exception of NEOs. For instance, going from the Moon to LEO requires a delta v of 4.5 km/s, which is half the value required to travel from the Earth's surface to LEO.

Water Utilization

Water is a key lunar resource. This is the most valuable resource for supporting human life. The fact that water has been detected at the lunar poles, as demonstrated by the Clementine and Lunar Prospector missions, has changed the way we think about settling the Moon. These missions discovered indirect evidence of water both on the South and North Poles. Verifying the existence of water and assessing how easily it can be extracted and transformed must be one of the first steps of our strategy. A robotic mission is required for this purpose. If a sufficient amount of water cannot be easily extracted on the Moon, it will be necessary to speed up the search for water on NEOs for extraction and transport to the Moon.

Strategic Roadmap for Moon

First Outpost

Once we assume that using water on the Moon is feasible, the poles will become the first locations for human settlement. For the moment, there is no evidence to suggest one pole over another. A near-polar site would have low but constant levels of solar energy. This continuous sunlight and stable environment would permit simpler support systems (thermal insulation, energy management). Due to the low declination of the Sun near the poles, surface features of the Moon, such as crater borders, may be used for radiation and solar flare protection. Another advantage of a polar location is that dark and cool polar craters could be used for propellant storage.

Initially, this first human outpost will be completely dependent on Earth. As in-situ resource utilization techniques are implemented, this outpost will progressively become more autonomous. Prior to outpost expansion, the following resource utilization infrastructure must be developed:

• nuclear power during the 14-day lunar nights and solar power during lunar days.
  
• lunar surface transport system (e.g. using mass driver techniques).
  
• water extraction for use in life support systems, and propellant for space and surface transport.
  
• regolith mining for construction.

See Chapter 2.5.1 for more details regarding the utilization of lunar resources.

Lunar Base

Upon implementing in-situ utilization techniques, the first lunar outpost will expand into a self-sufficient polar settlement. This settlement will serve two purposes:

• Use as an experimental platform to investigate/validate critical technologies and scientific questions (e.g .effects of space on humans); can be used to test technologies for future Mars missions.
   
• Starting point of expanding human presence on the Moon, leading to the privatization of Moon settlement research and activities.

Figure 2-2 presents a possible layout of such a polar lunar base. Note that this settlement's primary purpose is to serve as an experimental test bed for expanding human presence on the Moon and Mars. Note that the figure does not respect the scale for each element. In fact, each hazardous zone (spaceport, power generation zone, and storage zone) shall be a few kilometers distant from the habitats. In the same way, the extraction zone and the research center must be separated by several kilometers. The extraction plant may create an artificial atmosphere that could contaminate certain experiments. The figure does not include the protection against radiation that is obtained via a 2m thick layer of regolith (O'Neill, 1989) covering the infrastructures, or water shielding methods.

A polar site is not ideal for physical science experiments. Radio telescopes would benefit from being located on the far side of the Moon, away from Earth interference. However, infrastructure development techniques learned from establishing a polar base can then be applied at more suitable locations. For example, new assembly techniques as well as materials extracted at the polar surface would facilitate the construction of a large radio telescope. Once a Lunar base is established, assembling large but simple structures is no more complex than constructing a space station in low Earth orbit.

In parallel with science experiments and resource exploitation, we propose to use the time spent in Moon settlements to learn about the limitations imposed by the space environment on the human body.

The first step includes establishing a lunar life sciences and human performance facility. The lunar environment, with no atmosphere, no magnetic field, and low gravity provides a unique site for life science studies and space operational medicine. For human expansion into space and progression of the Step-by-step strategy, an extensive database of space life science research is required. Currently, our knowledge of the long-term physiological effects of the space environment is very limited and has been derived from US Skylab flights of up to 84 days and stays on MIR of up to 14 months (Garshnek, 1990). See the table in chapter 2.3.3 for current data on Human Factors. Data collection efforts using LEO and ground-based studies have shed some light on this subject, but are of limited value compared to Moon-based studies. In addition, due to its low gravity and lack of shielding from radiation, the Moon provides a better simulation of the environment of other planetary bodies. The lunar life sciences and human performance facility will focus its activities on determining safety and working constraints, and finding solutions to enhance human performance and life science studies.

Initially, research at this center should focus on radiation biology studies since this is currently regarded as the "show-stopper" for human space travel. Earth-dwellers are exposed to 100-200 mrem/year of radiation. Currently, the astronaut radiation exposure limit is 50 rem/year with a career limit set at 400 rem (Stanford 1999). The radiation threshold for effects on the human body is at 20 rad/year and much more is required for illness or discomfort. The lunar surface is fully exposed to galactic and solar radiation. Heavy primary galactic radiation and solar flares are of primary concern. The only direct human experience with heavy primary galactic radiation is from the Apollo 12 mission where brain and retinal cell loss estimates were of the ratio of a few in a million, and neuronal loss estimates were one in ten thousand (O'Neill, 1989). Some of the primary objectives of this facility will be radiation monitoring, hazard assessment, shield testing, and radio-protective techniques (i.e. chemoprevention).

The major objectives of such a facility include developing psychological-physiological support systems. The lunar surface is the ideal location for human isolation studies. As human mission length increases, human behavior and performance issues such as personal psychology, interpersonal relations (i.e. crew cohesion) and psychophysiology (i.e. stress and sleep) will increase in importance. The collection of physiological data is objective and is therefore routinely done on short duration flights. However, behavioral research is more complicated due to subjective reporting and lack of methods to accurately quantify data. Currently on Earth, attempts are being made to perform such experiments using analog environments such as nuclear submarines, Antarctic research stations, and polar expeditions. Such model environments may be more cost-effective than simulated studies in space, however, such studies vary considerably in terms of crew size and characteristics, mission objectives, and environmental conditions. Also, certain space-specific issues such as the effects of microgravity and the absence of a diurnal cycle on human behavior cannot be examined under such conditions (Space Studies Board Report, 1998). The experience of space flight is unique. Therefore, an accurate simulation of behavior within the microgravity environment of a space vehicle can only be performed in space. Isolation studies standardized to emulate future Mars missions and colonies would provide accurate and mission-specific data that could be implemented to refine existing crew programs.

As the facility grows and becomes more autonomous, Mars crew training may also shift to this site. Mars surface activities such as EVA, habitat construction, and scientific surveying may be practiced on the lunar surface. In addition, the technologies involved in such activities may also be tested prior to use on Mars.

A lunar laboratory will also provide a unique environment for life science studies. The emerging discipline of exobiology would particularly benefit from the creation of a lunar lab. The limits of the evolution of life may be tested under the extreme conditions of low temperature, high vacuum, and high radiation.

Expanding Human Presence on the Moon and Beyond

Once a self-sustaining polar base is established, humans may use the settlement techniques they have learned to spread across the lunar surface. Ideal locations for physical science research, resource utilization and eventually for the purpose of space tourism should be targeted. It is evident that prior to expanding the human presence on the Moon, a systematic robotic investigation of ideal resource locations will be required. This multiple rover venture would benefit from the precursor mission detailed in Chapter 4.

If the private sector is in a position to benefit from the infrastructures and technologies developed, a new economic niche will emerge. Those in this niche may take over the cost and management required to maintain permanent bases on the Moon. Moreover, the above efforts will not only establish multiple moon settlements but will also determine the feasibility and cost-effectiveness of a space tourism venture. The Apollo sites appear to be of some interest since they are well known and do not require a robotic mission for mapping.

Once we are ready to spread across the lunar surface, we are also ready to leave its surface. Mars … here we come.

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