John A Chapman mining the moon 20060723

8th ILEWG CONFERENCE

ON EXPLORATION AND UTILIZATION OF THE MOON

New Century Hotel, BEIJING, CHINA

23-27 July 2006

Cosponsored by CNSA and ILEWG

Development and Operation of a Surface Mine in a Remote Location - South Polar Region of the Moon

John Chapman, J.A. Chapman Mining Services; Marc Schulte, Marc Schulte Mining Services

NASA has announced a schedule and plan for the creation of a lunar base within 16 years as a precursor to establishing a base on Mars. Space agencies from Europe, Japan, India and China have expressed support for the NASA plan and/or their separate plans for a lunar base. This plan to explore and inhabit the Moon and then Mars is driven by the triple goals of scientific research, lunar/asteroid resource extraction and saving the earthbound human species from eventual extinction by asteroid/comet impact or super-volcano eruption. This paper proposes the application, on the Moon, of equipment and mining methods already well proven on Earth in very cold and dusty environments. The authors present an innovative combination of existing technologies for exploration and mining, including: mobile equipment, spare parts, sample analysis, remote controls, semi-autonomous controls, remote equipment "health" monitoring, real-time precision location and guidance, and the use of broadband WiMAX for communication to and from the proposed lunar base and Earth's Internet.

REFERENCES

Lewis, J.S., Mining the Sky, Addison-Wesley, Reading, 1997.

AUTHORS

John A. Chapman, B.Sc., FCIM, is a Professional Mining Engineer (British Columbia). He has worked 41 years in the mining industry in operations, engineering and as an executive. He has been instrumental in the development of several surface mines in Canada - some in adverse northern locations. He also has worked in heavy construction on the DEW line in the Canadian Arctic and is a proficient operator of most large mining equipment. Marc Schulte, B.Sc. is a Mining Engineer in Training (EIT, Alberta). He has worked five years in the mining industry as a surveyor, mine planner, and a heavy mobile equipment supplier. His mining experience has been in mountain coal and metal, prairie strip, oil sands and hard rock diamonds - all in Western and Northern Canada.

Chapman & Schulte, July 2006 1

Development and Operation of a Surface Mine in a Remote Location - South Polar Region of the Moon

John Chapman, J.A. Chapman Mining Services; Marc Schulte, Marc Schulte Mining Services INTRODUCTION: NASA has announced a schedule and a plan for the creation of a permanent lunar base within 16 years as a precursor to establishing a base on Mars. Space agencies from Europe, Japan, India and China have expressed support for the NASA plan and/or their separate plans for a lunar base. This plan to explore and inhabit the Moon and then Mars is driven by the triple goals of: (1) saving the earthbound human species from eventual extinction by asteroid/comet impact or supervolcano eruption, (2) scientific research, and (3) lunar resource extraction. To be successful the enterprise will need to embrace innovative methods of financing, transportation, mining, processing, habitation, communications and power generation. Wherever possible equipment, systems and procedures already commonly used on Earth should be adopted (with only minor modification, as required) in order to reduce costs and risks. THE RISK TO HUMANS AS A SINGLE PLANET SPECIES: John Young, Apollo Astronaut, in his opening remarks at the 2003 Lunar Conference in Hawaii said that, "humans cannot survive as a single planet species as evidenced in the Earth's fossil record of mass extinctions, mainly by comet/asteroid impacts and supervolcano eruptions". The most recent mass extinction (more than 75% of species destroyed) occurred 65 million years ago at what is called the Cretaceous-Tertiary boundary (Favstovsky et al, 2005). The scientific community has studied this event very thoroughly and they have located what is believed to be the impact center called the Chicxulub Crater on the Yucatan Peninsula in the Gulf of Mexico. They have speculated that the collision event was caused by the impact of an asteroid as they identified a pervasive thin dust layer, with an anomalously high concentration of iridium (common to certain asteroids) at the K-T boundary, spread around the Earth. They estimate the size of the asteroid at approximately 10 km diameter based upon the size of the crater (~150 km diameter). There are at least five other mass extinction events recorded in the geological record dating back to the late Cambrian, approximately 500 million years ago. Experts, including NASA, have observed and catalogued about 1,100 near-Earth objects measuring more than one kilometre in diameter. The International Astronomical Union has recently set up a special task force to specifically focus on threats from near-Earth objects. Expanding this database of near-Earth objects crowding the Earth's neighborhood will help in producing an early warning system and perhaps focus the urgency to study methods of intercepting and deflecting potential impactors. About 74,000 years ago, the Toba supervolcano erupted and ejected almost three times as much volcanic ash as the most recent major Yellowstone eruption at Lava Creek (~630,000 years ago) and about 12% more ash than Yellowstone's largest eruption at Huckleberry Ridge (~1.8 million years ago). Toba's super-eruption ejected several thousand times more material than erupted from Mount St. Helens in 1980, leaving a 2,800 square kilometre caldera (Knight et al, 1986). Toba rained down approximately 15 cm of ash over the entire Indian subcontintent and may have caused a planet wide die-off. It is possible that Toba's super eruption created an Earth-wide high-atmosphere dust cloud creating a global cold spell (~3.50 C decline) that might explain a mystery in the human genome. Recent mitochondrial DNA work suggests that the human race has passed through a genetic "bottleneck" within the Toba timeframe. It is estimated that the human population was reduced, at that time, to a few thousand individuals. LUNAR RESOURCES: Significant amounts of scientific research have been directed at the Moon, principally since the USA (Apollo) and the Soviet Union (Luna) commenced their lunar programs in the 1960s. Ever increasing amounts of data, at increasingly higher resolutions, have been collected during and since the Apollo program. SDIO's Clementine (1994) and NASA's Lunar Prospector (1998-1999) remote sensing satellites have mapped the Moon's topographic surface, magnetic field, gravitational field and the distribution of some molecules and/or elements (mainly looking for water). ISAS’s Hiten (1990-1993) satellite conducted guidance and navigation experiments to prepare for future lunar and asteroid missions. At this time the European Space Agency's SMART 1 remote sensing satellite, propelled by a highly innovative electric engine expelling xenon gas ions, is in a lunar polar orbit and is capturing high resolution images in visible, near-infrared and X-ray wavelengths. In addition, it is pioneering the use of very high bandwidth optical communications (laser) as well as unique navigation hardware and software for autonomous navigation (tracking stars, planets, asteroids and the Moon). Many more very high-technology lunar satellite orbital missions are planned leading up to the first robotic landings scheduled in 2010 and human landings in 2016. In order of planned launches the satellites are: Chandrayaan-1 (ISRO, 2007), Chang'E (CNSA, 2007), Selene (JAXA, 2007) and LRO (NASA, 2008). All this activity is related to establishing a lunar base that could service Earth's satellite fleet and provide a shallow-gravity-well fuel facility (pit-stop) for space ship launches to Mars and beyond. Lunar gravity is approximately 1/6 that of Earth's (g = 1.62 m/s2) and it has a considerable asymmetry causing low altitude satellites to be inherently unstable, requiring active propulsive corrections. In preparation for landing human and related support


exploration, mining and processing equipment payloads on the Moon, NASA is designing a new heavy lift launch vehicle called Ares V as part of its Constellation Program. The versatile heavy-lifting Ares V is a two-stage vertically stacked unmanned launch system. The launch vehicle can carry 130,000 kg to low Earth orbit and 64,000 kg to the Moon. The complementary Ares I crew launch vehicle, an in-line two-stage rocket configuration topped by a Crew Exploration Vehicle, is being designed to carry the astronauts to low Earth orbit for assembly with the Ares V payload for transit to the Moon. The Ares I and V launch system load capacity to the Moon exceeds that of the Saturn 5 system (49,000 kg) that was the workhorse of NASA's Apollo lunar program. Lunar resource extraction is focused upon the essential elements hydrogen and oxygen. These elements (H and O) or molecules (H2 and O2) are required for support of human life ("air" and water), rocket propellants, fuel cells (mobile and stationary), agriculture and aquaculture. Based upon NASA's Apollo and Soviet Union lunar program sampling, and more recent remote sensing, it appears that the lunar regolith contains O (~41%) and H2 (55 ppm) in concentrations that could be recoverable. However, extraction of the O requires sophisticated methods as it occurs in the mineral ilmenite. Hydrogen, on the other hand, is in the form of an adsorbed volatile (H2) but it does occur in only low concentration. The real prize then would be to discover water ice (high-grade and easy to process) in the regolith - that however, is not likely to occur anywhere other than within deep permanently shadowed craters at or very near the lunar polar regions (cold traps), as defined by Clementine and Lunar Prospector missions. The lunar crater cold traps offer a significant challenge to human entry due to a very low ambient temperature at -2330 C. Clementine beamed radio waves into the Moon and echoes of these waves were obtained by the large dish antennas of the Deep Space Network on Earth and it was found that the cold trap regions around the South Pole have the reflectance properties of ice, rather than the ground up rock powder characteristics of the lunar surface outside the cold traps. Water ice reflects brightly similar to a headlight reflector on a bicycle fender due to translucent internal reflections. Lunar Prospector clearly showed an enrichment of hydrogen (H) in polar regions but could not determine whether it was in the form of water ice (H2O), molecular hydrogen (H2), elemental hydrogen (H), or some other form. The water ice issue remains highly controversial and can only be solved by more remote sensing and yet to be performed robotic sampling. Potentially the highest value element on the Moon is He-3 an He isotope that when fused with deuterium forms He-4, one proton and an immense amount of fusion energy. One kilogram of He-3 burned with 0.67 kg of deuterium yields 166 million kW-hr of energy. As the entire USA electricity consumption is ~3.75 TW-hr it follows that only 25 t of He-3 could power the entire USA for one year, translating to a He-3 fuel value FOB Earth of about $1.0 billion per t. However, there are difficulties: (1) testing has not yet demonstrated any operations well above the break-even point in a fusion reactor, and (2) He-3 occurs in the lunar regolith at a very low concentration of ~5 ppb in the form of an adsorbed volatile (similar to H2). The mining operation would need to excavate and process 200 million t of regolith to recover one t of He-3 – that equates to mining the top two metres of a region 8 km square, using a regolith bulk density of 1.6 t/m3. The proponents of He-3 will need to find much higher concentrations of the element before it can be seriously considered a commercially viable fuel source. Reference Schmitt 2006. As geologists on Earth know - there is always the potential to make some new and exciting mineral or elemental deposit discovery. This will almost certainly be the case on the Moon. FINANCING OF SPACE RESEARCH, EXPLORATION AND DEVELOPMENT: Financing of space research, exploration and development in the past has been mainly by governments. To create a vibrant and sustainable space program the private sector needs to lead the charge, building upon the foundation established by mainly the USA and Soviet Union governments. There is an analog that could point the way to rapidly opening space to private enterprise – that is the Canadian flow-through tax incentive for mineral exploration. The flow-through tax credit program in Canada has facilitated the raising of billions of dollars yearly, mainly from wealthy individuals, by the exploring companies – and this has kept Canada in the forefront of world mineral exploration and mine development. In addition, Canada has, through this tax incentive, “grown” a large base of experts in science, technology, legal, accounting, finance, etc. for mineral exploration and mine development world wide. Statistics from the 2005 Canadian intergovernmental working group on the mineral industry reported: (1) globally, Canada continues to be the foremost destination for exploration capital. In 2004 some 20% of the mineral exploration programs planned by the world’s mining companies were expected to be conducted in Canada. As for Canadian companies, they were expected to undertake 43% of all the exploration programs in the world in 2004, a share that is by far the largest of the global mineral exploration market, and (2) in 2003 C$12.7 billion in equity financing was raised for mineral exploration and development projects around the world during that year. More than 45% of the new funds raised were for companies listed on the Canadian stock exchanges. These are amazing statistics as Canada only represents 7% of the land area on Earth, and only 0.5% of the world’s population. It is important to understand the details of the tax-driven incentive that encourages the exploration and development of Canadian natural resources - the government allows Canadian natural resource companies to issue common shares that entitle the holder to certain tax


benefits. These shares are called flow-through shares. Canadian natural resource companies have certain expenses, known as Canadian Exploration Expenses (CEE), which can be deducted 100% for tax purposes by the purchasers of flow-through shares. In addition to benefiting a taxpayer in the current taxation year, these tax deductions can be carried back three years and carried forward seven years. In addition, there is also a 15% tax credit available to investors anywhere in Canada for "grass roots" mining exploration expenses incurred in Canada - this applies only to mining of metals and minerals and not for extraction of oil and gas. For investors in every province and territory of Canada, the tax credit is at least 15% as long as the "grass roots" mining exploration occurs somewhere in Canada. In addition, some (but not all) of the provinces and territories have added their own tax credit, ranging from 5% in Ontario to 20% in British Columbia. The provincial tax credit only applies if the investor is resident in the province and the exploration occurs in the same province. In addition to benefiting a taxpayer in the current taxation year, these tax credits can be carried back three years and carried forward 10 years. Just imagine the impact of the USA adopting a similar tax-driven incentive for space research, exploration and development – tens of billions of dollars would be raised annually for space enterprises. THE DRIVE TO EXPLORE AND DISCOVER (ADVENTURE): Humans have a genetic "wiring" that drives exploration (risk) for discovery (reward) of new places and things - the Earth no longer holds either the exploration potential or the rewards needed by society. In addition, there is a compelling need to avoid the asteroid/comet hazard - it is time to move on to the rest of the Solar System and beyond into the Cosmos. DETERMINING THE BEST LOCATION FOR A LUNAR MINING BASE: Based upon remote sensing the most promising region identified for the first lunar mining base is in the South Polar Region near Malapert Mountain (Figure 1). Remote sensing has located what may be water ice (the single most important resource) in permanently shadowed craters near Malapert. The Mountain peak offers an ideal site for optical (laser) relaying of data between the lunar base and Earth (2.6 second round trip communications time). Malapert, while on the edge of the “Far Side” of the Moon, is high enough to be in constant view of the Earth (enabling direct laser communications) and it receives sunlight approximately 90% of the time, making it one of the “sunniest” locals on the Moon. Another advantage of this Region is the moderate temperature in the highlands at -530 C +/-100, compared with the permanently shadowed craters at -2330 C +/-00 and the equator at -180 C +/-1400. The long duration sunlight at Malapert will facilitate solar-electric power generation to power communications equipment. Solar spectra power density at Malapert is ~1.37 kW/m2. The Shoemaker Crater, at 420 East Longitude, 880 South Latitude appears to be a prime candidate for water ice within direct view of Malapert (~90 km from peak to Crater center) as the orbiting Lunar Prospector had detected high hydrogen abundance in the Crater. This Crater was originally named “Mawson” - the name was changed when the Lunar Prospector satellite was crashed into the Crater on July 31, 1999 in an attempt to evaporate water ice with the kinetic energy of impact (unfortunately no plume was visible from Earth). Lunar Prospector was carrying the ashes of the late Eugene M. Shoemaker (1928-1997) renowned geologist and astronomer. Work done by Bussey et al (2003) indicates that at 88 degrees Latitude a crater of ~20 km diameter will have a permanent circular central shadow area in the crater bottom representing ~80% +/-15% (summer to winter variation) of the crater floor, depending upon the height and regularity of the crater rim. The permanent shadow percentage (cold trap) is only slightly dependent upon the crater diameter; it is Latitude that is the significant dependent variable. Depending upon the temperature of the area (around the outside edge of the crater floor) that is in sunlight, this may be the logical place to commence regolith resource testing and then mining. It is important to recognize that the lunar day is equal to 29.53 Earth days (synodic period). If the sunlit region in the Shoemaker Crater is similar in temperature range to the South Polar highland region of -530 C +/-100, then this would be an ideal place to start a lunar mining base assuming the resource is confirmed. What makes this an ideal place to start is that it will facilitate H2 and O2 extraction from the sunlit regolith and at the same time place the base of operations in close proximity, on near level terrain, to the cold trap at the Crater center - the possible source of high-grade water ice. Once the lunar base is well established in the sunlit area of the Shoemaker Crater floor, short excursions with unmanned remote controlled and/or autonomous vehicles could be made into the cold trap areas to test for water ice. This procedure would allow the lunar base team to incrementally "harden" the exploration, and ultimately the mining equipment, for more aggressive long duration operations into the cold traps. NASA’s LRO in 2008 will provide South Polar Region digital topographic and temperature models in resolutions that will greatly assist in planning a lunar mining base – then only the resource determination is required within topographic and temperature regimes that are suitable for initial human operations. If NASA’s LRO finds that temperatures in the sunlit regions of the floor of Shoemaker Crater are well below -530 C then the first mining operations will need to be established at the warmer rim of the Crater in an area where relatively efficient ingress and egress can be established for future excursions into the cold trap region for water ice exploration and mining. There needs to be more remote sensing to determine the temperature range in partly shadowed polar craters.


THE LUNAR WORK ENVIRONMENT: The lunar environment is very hostile to humans and machinery - some of the challenges are as follows (Alexander, 2005):

• Temperature: polar highlands = -530 C +/-100, permanently shadowed craters = -2330 C +/-00, Equatorial = -180 C +/-1400 and mid-latitudes = -360 C +/- 500 - need more study on the temperature range in partly shadowed craters

• Solar Constant: 1.37 kW/m2 (perpendicular to the solar rays) • Atmosphere: thin, essentially non-existent ("hard" vacuum) • Radiation: high ionizing radiation as no atmosphere to provide protection (significant danger to humans) • Meteoroids: direct high velocity impact as no atmosphere to "burn" them up • Gravity: 1.62 m/s2 (~1/6 of Earth's) • Length of Lunar Day: 29.53 Earth days (synodic period) • Dust: very dusty and a photoelectric change in conductivity at sunrise and sunset (terminator) causes dust particles

to levitate and adhere to surfaces (hard on equipment and affects visibility) - need more study on this phenomenon • Seismic Activity: few events and of low magnitude (<4 on the Richter Scale) • Distance between Earth and Moon: 385,000 km (center to center at accuracy of 1 part in 10 billion) • Travel time of electromagnetic waves between Earth and Moon: ~2.6 seconds round trip (speed of light: 299,600

km/s)

Figure 1. Combined Clementine mosaic and Earth-based radar image of the South Polar Region of the Moon. Malapert Mountain is located at 00 Longitude and 860 South Latitude (NASA).

0

90

180

850 S LAT

MALAPERT MTN. ~8,000 m above mtn. base

SHOEMAKER CRATER 51 km diameter

2.5 km deep

2700 LONG

NEAR SIDE

FAR SIDE


LUNAR REGOLITH CHARACTERISTICS: Lunar sampling returns from the Apollo (382 kg of rock and soil) and Luna (0.33 kg of rock and soil) programs and the collection of meteorites (Antarctic) from the Moon has provided materials for scientific study. Those studies provide estimates of elemental resources and physical characteristics, both important when considering establishment of a lunar mining base. It is important to understand that the sampling is biased toward the lunar maria materials as most of the Apollo and Luna landings were in the flat, smooth terrain of the maria regions. Some of the scientific information based upon lunar maria regolith samples is as follows (Wegeng, 2005):

• Element Concentration: O = 41.3%, Si = 20.4%, Fe = 13.2%, Ca = 7.9%, Al = 6.8%, Mg = 5.8%, Ti = 3.1% and other = 1.5%

• Volatile Concentration (mainly deposited by solar wind): H2 = 55 ppm, He = 29 ppm, C = 104 ppm, N = 95 ppm, He-3 = 5 ppb

• Definitions: Regolith - broken up rock material, Soil - <1 cm portion of Regolith, Dust - <50 micron portion of soil, Agglutinate - pieces of minerals, rocklets welded together by shock-melt glass (from ejected impactor "melts")

• Adsorbed Volatiles: the bulk of lunar soil is <1 mm in size and contains a large portion of the volatiles due to the small particle's high surface area (adsorption)

• Specific Gravity of Lunar Surface Material: range from 2.3 to >3.2 • Porosity of Lunar Surface Material: ~50% • Bulk Density of Lunar Surface Material: ~1.6 g/cm3 • Slope Stability: a vertical cut can safely be made in lunar soil to a depth of about 3 m; an excavation slope of 600

can be maintained to a depth of about 10 m - lunar soil is very angular and has experienced slow shaking over eons of time making it well "compacted"

• Friction: the US Bureau of Mines found that exposing lunar simulant to a vacuum long enough, for nearly complete out-gassing, caused increased friction up to 60 times

HYDROGEN/OXYGEN DEPOSIT DRILLING, RESOURCE DETERMINATION AND MINE PLANNING: Once robotic sampling has confirmed the general area with the highest grades of H2 and O2 an actual ore body will need to be delineated. This will be done through hammer seismic and auger drilling, which will require the first mining equipment to be shipped to the lunar surface and assembled. Hammer seismic (vibrator mounted on a small excavator – see Figure 3, D) will assist in defining the lunar bedrock profile and any regolith subsurface variations prior to auger drilling. The excavator mounted auger will then drill the surface to ~2 meters depth on a grid pattern to define a large enough H2 and O2 resource to satisfy the lunar base’s needs for at least ten years. A neutron activation probe and an XRF probe would be utilized in each augured borehole in order to analyze the hole for H2 and heavy elements respectively - reporting the results of the boreholes in real time. Analyses would be done on each one metre of the auger hole (two samples per hole). Both the hammer seismic testing and the neutron probing, along with human inspection from time to time, will confirm the presence of any water ice which would be considered a high-grade ore deposit. The presence of water ice, while good news, could pose a mining challenge as it would probably cement the highly siliceous regolith particles together making the mining more difficult (more breakout force needed) and increase the abrasion and wear on ground engaging tools (auger drill bits and excavator bucket teeth). Once the deposit has been delineated standard block modeling methods would be used to optimize the staged pit outlines (mine plan) to yield the amount of H2 and O2 designated for a ten year lunar base operation. In order to determine this optimum mining sequence the deposit is segmented into 3-dimensional blocks; each block is then assigned a value by interpolating the assay grades from drill samples and applying bulk density, element recoveries (mining and processing) and element values into each block (Lambert, 2005). Each block is also assigned costs of mining, transportation and processing. The lunar mine would be designed with one metre cubed blocks. Optimized stages are developed by running the model with a stepped series of element values. The stages that are designed (outlined) by the optimizing numeric algorithm, utilizing the lowest element prices, are the stages that have the greatest economic return, and would be mined first. Mining at the highest grade and lowest strip ratio first (lowest risk and highest reward) allows time to train operating crews and to establish efficient and effective operating systems and procedures so that in later years lower grade and higher strip ratio areas may still be mined profitably. This method of optimization is especially applicable in remote operations where it minimizes crew size, equipment fleet, support facilities and spare parts in the early years of operation, thereby minimizing operating risks. Companies providing sophisticated 3-dimensional mine planning software include: Gemcom Software International Inc., Mintec Inc., Maptek Pty Ltd. and Mincom Limited.


EQUIPMENT FOR MINE DEVELOPMENT AND OPERATIONS: Equipment must be versatile so that it can perform both development and operations tasks. The first equipment should be small, and then as development and operations mature, larger but similar equipment should be deployed (see Figure 2). The first small equipment could then be adapted (radio isotope thermal-electric generator, heat tracing, insulation, etc.) for exploration of cold traps in the vicinity of the lunar base for water ice (high risk, high reward). The equipment will use current designs and currently applied modifications. The hydraulic excavator is the most versatile piece of construction equipment available today, and it will be the basis for the lunar mining equipment employed. Hydraulic excavators are used successfully, with high availability, in the Canadian high arctic operating in very cold (~-500 C) conditions digging permafrost and blasted rock (dusty and abrasive). Excavators are manufactured by Caterpillar, Hitachi, Volvo and Komatsu, with Caterpillar excavators having the greatest amount of commonality in parts to other Caterpillar fleet machines. In order to have the versatility required for all of the development and operation tasks, the excavator will be equipped with a quick coupling mechanism. The quick coupling mechanism will allow the tools on the end of the stick of the excavator to be switched efficiently (see Figure 3). The bucket would be used for excavating material. It would also be used for development work, for example building a regolith shield for the lunar camp. The rock breaker would be used for breaking up lunar regolith, ice water and other excavated materials for ease of digging with the rock bucket. The auger would be used for exploration drilling, or any drilling required in the development phases. The vibrating compactor would be used in development, as well as seismic hammer exploration. The material handling arm, along with slings or hooks, would be used in development, as well as support operations for the mine, process facility and base. A neutron probe and XRF probe could also be attached to the material handling arm to assist in exploration work.

Figure 2. Proposed principal piece of development and mining equipment – hydraulic excavator powered by fuel cell.

Komatsu PC18M-2 (Earth 1g Environment) Power 11.2 kW Operating Weight 1933 kg Ground Pressure 0.33 kg/cm2 Travel Speed 2.3 km/hr (low) 4.3 km/hr (high) Gradeability 30 degrees Drawbar Pull 1700 kg Digging Height 3615 mm Bucket Reach 3935 mm Digging Depth 1785 mm

Komatsu PC35MR-2 (Earth 1g Environment) Power 21.7 kW Operating Weight 3840 kg Ground Pressure 0.35 kg/cm2 Travel Speed 2.8 km/hr (low) 4.6 km/hr (high) Gradeability 30 degrees Drawbar Pull 3600 kg Digging Height 5010 mm Bucket Reach 4550 mm Digging Depth 2650 mm

THE HYDRAULIC EXCAVATOR IS THE MOST VERSATILE

PIECE OF CONSTRUCTION

EQUIPMENT AVAILABLE TODAY


The excavator, as designed on Earth, provides hydraulic force and volume to accelerate and swing the mass of the material in the bucket of the machine to match Earth's gravity. In the lunar gravity there would be a potential to over-balance the machine because of the reduced normal force on the machine when swinging the excavator with a loaded bucket (F=ma stays the same but gravity is reduced). The swing function (speed) of the excavator will be limited for lunar operations so that there is a reduced hydraulic fluid flow. In the excavator-trailer combination, shown in Figure 4, the trailer undercarriage will be the same as on the excavator, to provide commonality in parts, and it will include its own hydraulic drive motor (same as on excavator). The trailers will be loaded by the excavator and towed by the excavator to the processing plant primary ore feed hopper for side dumping. The excavator hydraulic pump will have enough capacity to power both it and the trailer unit, as long as the digging function is not engaged. The excavator-trailer will be connected with a quick coupling tow bar and will be used to move material in the mining phase. A trailer designed for work on Earth would be able to carry roughly 6 times the amount of material on the lunar surface, because of the lower gravitational force. For functionality though, the volume of the trailer will have to be limited to its required maneuverability on the undercarriage and tracks of the excavator. As such, the trailer will be volume limited, and not payload limited.

Figure 3. Small excavator and working attachments. The excavator will be powered by fuel cells similar to those used successfully in NASA's Apollo and Space Shuttle programs. These fuel cells burn pure H2 and pure O2 and exhaust water and are currently being manufactured by UTC Power (United Technologies Corporation). The power requirement of the initial excavator/trailer would be ~11 kW (see Figure 2). Present fuel cell technology pretty much limits fuel cells to continuous reactant flow rates for peak efficiency, so highly variable peak power requirements such as those required by a hydraulic excavator may disable the power generator. More work is required in this area, including the integration of highly efficient capacitors into the power operating system, to provide balance between peak power demands. The electric motor driving the hydraulic system will also need to respond to wide variations in power demand. Mining equipment would be operated remotely from nearby, at the lunar base control center, or from Earth as it would be extremely difficult for a suited (space suit) crewperson to effectively control the excavating equipment "in the seat" because of limited mobility. Remote controlled operation of mining equipment on Earth is a well established practice. Maintenance

QUICK COUPLING ATTACHMENTS WILL FACILITATE SIGNIFICANT VERSATILITY, INCLUDING: (A) ROCK BUCKET (B) ROCK BREAKING (C) AUGER DRILLING (D) VIBRATING COMPACTOR & SEISMIC HAMMER (E) MATERIAL HANDLING ARM

A B

C D E


of equipment will need to be done in a pressurized shelter so that crewpersons can perform the maintenance or repairs without being suited. Undercarriage and any ground engaging tools on the excavator and the trailer body will be made of hardened steel to minimize wear. The hardest steel commercially available, with consideration for low-temperature brittle fracture performance, will be utilized. This includes track pads, bushings, idlers, rollers, sprockets, bucket teeth, bucket wear plates, and trailer body plates. The widest available undercarriage track pads will be used for the excavator selected. The wider shoes will provide better float and stability on the lunar surface. Also, the tracked configuration for the excavator and trailer combination will be able to safely negotiate 30 degree slopes. The structure of the excavator, as well as the boom, and possibly the tools themselves will be heat traced. Equipment operators in cold climates on Earth will heat-trace the steel structures of their equipment in order to prevent cold weather brittle fractures. This same application will be employed on the lunar equipment. For the lunar application fully synthetic oils and greases that have relatively stable viscosity levels, even at very low temperatures, will be used for lubrication and hydraulic functions within the equipment. These products are readily available for use on Earth and they have been used successfully in the space programs. "Arctic" greases (containing molybdenum disulfide) will be used on the undercarriage and on all pins and bushings so that if there are leaks the lubricated components continue to roll. A standard method of ensuring the fluids and contacted metals are kept warm in an Arctic environment is the addition of fluid reservoir heaters. These heaters would be powered by the machine's electric alternator when operating and by external power when parked - this keeps the fluids running warm in the coldest temperatures and maintains heat within the machinery (metal structure). The lunar excavator fuel cell exhaust (water) will also need to be kept warm for transfer to the water storage or water processing facility. The equipment will require starting in a sheltered environment, but once operating, the internal temperatures will be much higher than ambient temperatures on the lunar surface. If a component fails and the machine shuts down, then a warm-up shelter will need to be placed over the machine before restarting it, if down more than about one hour. Therefore, at least two excavator-trailer setups will be required for operation on the lunar surface, to ensure one is available for operations at all times.

Figure 4. Excavator and side dump trailer using side-cut mining method in lunar regolith. MINING SYSTEMS AND PROCEDURES: The parallel cut method of mining will be utilized (see Figure 4). The excavator will dig a section 90 degrees perpendicular to the undercarriage and swing 90 degrees behind it to load an attached tracked trailer. When the excavator has excavated all material within its reach, it will then move parallel along the cut to continue excavating. The excavator will only excavate material within the defined mine plan and on the schedule in the plan. Once one deposit is exhausted, the equipment would move to the next highest value deposit.


Mine operations, processing and maintenance crews would include, at least: one mine engineer, one extractive metallurgical engineer, one electrician, one mechanic and one equipment specialist. Each individual would be cross trained to do both mine functions and process functions and each individual would have industrial first aid training. There is a definite need for individuals willing to multi-task. Also, wherever possible, all equipment should be standardized. This includes all mechanical, electrical and hydraulic functions and fittings for all equipment found in mining, processing, and the base itself. This standardization, as well as an inventory of spare parts and materials, is essential to keeping the operations running efficiently. There is a requirement for two crews of the makeup described above to work in cross shifts; as one crew rests, the other works, and vice versa, likely with some overlap. Lunar mining would be done during the daytime (~14.77 Earth days) and the regolith processing would be done at night. Work on the lunar surface will be extremely isolated, and crew members will be expected to continue working at the operations for long periods of time. Therefore, crew members must be carefully selected in order to run an efficient lunar base. They must be mentally stable and capable and have a desire to work in this environment; and the rewards for the crew members must match the risk involved. There must be a combination of exploration, mining, processing and space development skills, including intelligent, educated and practical individuals that are willing to contribute as a team to the successful accomplishment of all project objectives. The working environment must also be carefully designed. Crew quarters and medical facilities must be included in order to ensure high morale. A reliable source of electric power and heat is essential. A modern machine shop with maintenance and repair facilities to optimize equipment availability and productivity must be maintained along with a complimentary spares inventory. Lastly, an efficient communications network, both on site and to and from the Earth with internet access must be maintained for operations and for the crew. Ensuring high morale of crew members will provide the highest probability of success to all project goals.

Figure 5. Excavator delivering liquid hydrogen and oxygen modules for lunar Spaceport. THE IMPORTANCE OF HYDROGEN AND OXYGEN TO THE LUNAR MINING BASE (Lewis, 1996): The lunar mining base should concentrate on the production of H2 and O2 as they are the elements that are available in a high enough abundance to provide for the important functions of: human life (O2 and H2O), rocket propellants (chemical and nuclear), fuel cells (mobile and stationary), agriculture and aquaculture. Several techniques being studied by NASA for O2 extraction from lunar regolith that also produce metal byproducts are: H2 reduction in minerals and glass (iron), carbon reduction (iron and silicon) and electrolysis (iron, silicon, titanium and aluminum). These processes also propose evolution of volatiles (adsorbed H2 and He) by preheating of regolith. Studying methods of upgrading the feed to these processes by conventional physical metallurgical methods include: gravity, crushing and sizing, magnetic and electromagnetic separation, etc. will probably improve the process economics. Once water ice is located the processing will become as simple as melting and electrolysis (or fuel cell run in reverse) to directly produce H2 and O2 at a very significant cost saving over the other processing methods described. The waste material (tailings) from H2, O2 and metal recovery may be suitable for construction materials including: concrete, sulfur concrete, cast basalt, sintered basalt, fiberglass and cast glass. These materials are


important to the expansion of a permanent lunar base that would serve large scale, primary industries of mining, astronomy and space transportation (lunar spaceport).

Figure 6. Excavator moving lunar habitat module to new location. Habitat module is adapted from an underground mine refuge station design on Earth. The primary sources of life support for humans are both O2 and H2O. Humans can breathe pure O2 continuously at a pressure of 24.1 kPa (3.5 psi), but not at pressures much higher or lower than this value, for any extended period. The Apollo space program ran pure O2 at this pressure in the space suits used by crew members. Food energy for humans can be grown in a lunar base agriculture-aquaculture biosphere, with H2O being the main element for sustaining these greenhouses. Also, the CO2 which is produced from human exhaust would ideally be cycled to the greenhouses to stimulate growth of food and O2 producing plant life. Any H2O produced from human metabolism would be recycled to the greenhouses, or it could even be electrolyzed to H2 and O2 for use in any other functions requiring these elements. Excess CO2 can also be converted to O2 and solid C using high temperature gas phase electrolysis. Human waste produced from metabolism can also be burned to produce CO2, H2O and N2. Nitrogen could be added to the O2 as a fire retardant in work and/or habitat areas if warranted. It is interesting to note that H2 and O2 can be used in chemical rockets (specific impulse ~450 seconds) and also in nuclear thermal rockets (specific impulse, using H2 only, of 1,000 seconds to 10,000 seconds). Missions to Mars and further out into the Solar System will require the high specific impulse nuclear thermal propulsion systems to reduce travel times for humans. Oxygen can be introduced (O2 augmentation) into the exhaust of an H2 fueled nuclear thermal rocket to add thrust, but at the expense of speed (Freeman 1999). Fuel cells burning H2 and O2 would be utilized to power on-site mobile equipment and to power an emergency standby power system. The combustion of H2 and O2 in fuel cells to form H2O requires 2 parts H to 16 parts O (by weight), due to the atomic weight of each element. Water is the product of these fuel cell combustions and would be collected and recycled for future use. Fuel cells can also be reversed by providing H2O and electric energy to produce H2 and O2 - this is currently one of the preferred methods of H2 production for Iceland's "hydrogen economy". Storage of H2 and O2 at the lunar base will be a very important operating function that must be efficiently and safely undertaken. It is important to note that H2 (liquid) has a density of 0.076 g/ml (boiling point is -2530 C) and O2 (liquid) has a density of 1.153 g/ml (boiling point is -1830 C). This means that liquid H2 takes up ~15 times more storage volume than liquid O2 on an equal weight basis. The lunar base will need to run on a closed biosphere so that wherever possible all solids, liquids and gases are recycled. Much work is being done in this area on Earth and on the ISS. One item that should be studied is the use of an aquaculture lined "pond" as the water storage facility, rather than using tanks. Waste heat from the lunar base power generation system would be utilized to maintain proper operating temperatures in all of the base facilities including the agriculture-aquaculture biosphere.


EFFICIENT AND RELIABLE POWER FOR THE LUNAR BASE: Solar power cannot be relied upon to provide efficient and reliable energy to the lunar base - that can only be achieved by using existing nuclear technology, preferably a gas turbine modular He reactor (LaBar, 2002 and UIC, 2006). These nuclear reactors have a very high power density; they are safe and require very little maintenance. Initially a reactor generating ~1 MW electric (with ~1.5MW heat) would satisfy all of the lunar base's electricity and heat needs. A 100 kW fuel cell should be utilized for emergency standby power generation. Helium cooled reactors, such as the PBMR, produce very high grade heat (temperature ~9500 C) that would greatly assist in lunar regolith processing. Enough H2 and O2 would need to be stored to meet human, biosphere and emergency generator needs for approximately 45 days (approximate elapsed time for a rescue mission to arrive from Earth). TELECOMMUNICATIONS AROUND THE LUNAR BASE AND TO/FROM EARTH: All equipment on the lunar surface will communicate with a base control center through a site-wide mesh network. This base control center will communicate with the Earth’s internet through optical transmission (laser) directly from the lunar base control center to a satellite at L1 and/or via a relay on Malapert. Persons on Earth connected to the internet would be able to monitor the equipment and communicate with the inhabitants on the lunar surface in near real time. Presently lunar communications cannot be linked into the Earth's internet because of packet switching delays (2.6 seconds round trip Earth-Moon communications delay) which the system is not designed to handle. However, NASA is working with Dr Vinton Cerf, to create an interplanetary internet (IPN). Dr Cerf is one of the founding fathers (mid 1970s) of Earth’s internet, so the project is in strong hands. Currently, there is no lunar UTM high resolution datum available, and a local (virtual) metric grid coordinate system will have to be established in order to provide accurate location tracking of equipment and personnel on the lunar surface at and near the base. This would operate similar to Earth's global positioning system (GPS), and would use multiple microwave signal relays to devise a 3-dimensional location on this virtual UTM grid. NASA's polar orbit LRO planned for 2008 will establish a global geodetic coordinate system and a DEM for the lunar surface with 100% coverage in the polar regions. However, the DEM resolution will still be too coarse at ~+/-50 m horizontally (now ~+/- 4 km) to use for the lunar mining base operations. LRO photography, on the other hand, will be of very high quality as the Narrow Angle Camera (NAC) will provide panchromatic images at a spatial resolution of 0.5 m/pixel. This high resolution imagery will greatly assist in picking sites clear for landing of robotic missions and later human and large cargo missions to establish the lunar mining base. An array of at least 6 antennas would be positioned around the perimeter of the proposed lunar base and mining operations, to provide communications (~10 Mbps) and positioning (+/-10 cm) of all equipment and personnel, to the base control center, through a meshed network. The antennas must be positioned so that there is a horizontal and vertical difference in their locations, to provide proper horizontal and vertical resolution for the work area unit location determination, and if possible be in line of sight with each other. All equipment and work areas will likely be within a 2 kilometer radius area. The communications of the equipment to the base control center is required for remote operations of the equipment, health/safety monitoring, autonomous functions, as well as performance monitoring and reporting. The communications would be accomplished with a WiMAX - IEEE 802.16 broadband wireless mesh network (Intel, 2004). On Earth, Novariant Inc. has developed a product called Terralite XPS that accomplishes this meshed network functionality with high resolution ranging antennas. The system uses the antennas positioned around the site, as well as each system on both personnel and equipment to act as a part of the mesh of communications; receiving, transmitting and boosting the signal on to the next node in the mesh. These systems, and others like it, are currently being employed in surface and underground mines around the world. Through the communications network, the equipment can be controlled remotely, or work plans can be downloaded and the equipment can work semi-autonomously or even autonomously (NRC, 2006 and DeGaspari, 2003). Work plans can be designed on an identical virtual UTM grid as the one developed for the lunar surface, and the equipment can be made to follow the plans (common practice on Earth). Also, systems for the detection of pending collisions, and/or avoidance of unexpected topographical features on the lunar surface, are currently available that would allow the equipment a certain amount of rational self-conservation. International Mining Technologies has developed the MineMate Collision Avoidance system, which could be used for this application. For automation and remote control of the lunar base's mineral processing section, via the internet, there is well tested and cost effective Windows based "Wonderware" software available from Invensys Systems, Inc. The communication network would also allow real time monitoring of sensors placed on the equipment for the purposes of vital machine function health management and application productivity. Modular International Mining Systems Inc., Wenco International Mining Systems Ltd., Novariant, Inc., and Caterpillar, Inc. all have developed systems for mining equipment that perform these sensor monitoring functions. The Caterpillar VIMS (Vital Information Management System) system is


being employed at over 300 mining operations on Earth. The sensors on the equipment that the system is employed on can be viewed over the internet by the users of the system in a remote mine control room, as well as by Caterpillar in Peoria, USA. The equipment manufactured for mining application on the lunar surface would already have numerous sensors integrated into the vehicle design; and out of the box management systems would have the flexibility of adding additional sensors on the equipment for this particular application (for instance, temperature sensors on structural components of the equipment that are heat traced, in order to ensure the temperatures of the steel are kept in the desired range, or if the functionality of the heat tracing itself has failed). If the system detects an impending or abnormal condition in any of the machine’s systems, it can modify the machine’s operation to mitigate the issue, or if the issue is critical, it will send an alert to the management personnel of the equipment, notifying the nature of the issue, and possible solutions. In the lunar application that is proposed, all available methods for ensuring high equipment availability and functionality are imperative for success. The system will also be able to monitor the productivity of the machine by measuring vehicle speed, dig rates, delay times, etc. The information gathered from the productivity monitoring can be analyzed to develop better decision making and higher efficiency in the operation. On-site communication through the mesh network is required and, in addition, a communication link between the lunar base control center and Earth is essential. All information from the base and from the mining operations could be sent to Earth and many functions of the lunar mining operation could then be run from Earth, lowering both project costs and risks. Communication to Earth could be accomplished through an optical transmission via a relay satellite parked at Earth’s Lunar L1 point and/or an optical relay at Malapert. The optical (laser) link through satellite relay will feed and receive information via TCP/IP FTP protocol (IPN - capable). Deployment of optical communications in space will greatly increase the baud rate, reduce the power requirements and reduce the electromagnetic spectrum noise caused by present longer wave length ‘radio’ communications. ESA is leading the development of optical (laser) technology for transmitting at high data rates (50Mbps) with low mass, low power terminals, combined with secure, interference free communications between satellites and between satellites and Earth. Recently JAXA has joined with ESA to advance this important technology. The proposed lunar mining base also has the potential to use the proposed international lunar observatory to be placed on Malapert as an optical communications relay site. The observatory proposal is being championed by SpaceDev, Inc. and the Lunar Enterprise Corporation. RECOMMENDATIONS: To achieve the objectives of: (1) saving the earthbound human species from eventual extinction by asteroid/comet impact or supervolcano eruption, (2) scientific research, and (3) lunar resource extraction, the following actions by government and private enterprise (the space industry) are required:

• Cooperate to ensure that there are school and university programs that engage the subjects of space research, exploration and development

• Cooperate in establishing a tax regime that encourages space research, exploration and development • Re-establish and advance the work by the USA and the former Soviet Union in developing reusable nuclear thermal

rockets with LOX augmentation • Aggressively advance the research and development of small, safe, efficient and reliable gas turbine modular helium

reactors for stationary power and heat generation • Build on the leading work being done by ESA in the use of optical (laser) communications • Support the development of the interplanetary internet being championed by NASA • Establish an internet website that holds all of the space agencies' lunar data (remote sensing and surface sampling)

for access by the general public. The site should contain topography, photography, geology, geophysics, geochemistry, etc., all properly georeferenced in a common map projection. A good analog is the award winning British Columbia MapPlace website which is probably the best and most accessible georeferenced geoscience database on Earth. It presents data on British Columbia, Canada. See: http://www.mapplace.ca

• Rocket developers should stay with H2 and O2 propellants in order to ensure simplicity and reliability of refueling systems to be established on the Moon and Mars

• Work with Caterpillar, Inc. or other well established mining machinery manufacturers to plan for lunar deployment of construction and mining machinery - this will be cost effective and minimize lunar operating risks

• Cooperate in establishing industry standards for compatible "interconnection" of systems hardware and software that is important to space mission safety and efficiency

As Jim Benson, Chairman of SpaceDev, Inc. says - "ONWARD AND UPWARD!"


REFERENCES

Alexander, M., Jablonski and Ogden, K.A., 2005, A Review of Technical Requirements for Lunar Structures - Present Status, ILEWG 2005 Conference, Canadian Space Agency. Burton, L., Sharpe, Schrunk, D.G. and Thangavelu, M., 2003, Lunar Reference Mission: Malapert Station, In ILEWG 2003 Conference, Hawaii, Session 8 - Lunar Commerce, Enterprise and Technology. Bussey, D.B.J., Lucey, P.G., Steutel, D., Robinson, M.S., Spudis, P.C. and Edwards, K.D., 2003, Permanent shadow in simple craters near the lunar poles, Geophysical Research Letters, v.30(6), 1278. DeGaspari, J., 2003, Armchair Mining, The American Society of Mechanical Engineers Periodical. Favstovsky, D.E. and Sheehan, P.M., 2005, The extinction of the dinosaurs in North America, GSA Today, v. 15, no. 3, pp 4-10. Freeman, Marsha, Summer 1999, Back to the Moon with Nuclear Rockets, In 21st Century Science & Technology, pp. 56-63. Intel, 2004, Understanding Wi-Fi and WiMAX as Metro-Access Solutions. Knight, M.D., Walker, G.P.L., Ellwood, B.B. and Diehl, J.F., 1986, Stratigraphy, paleomagnetism, and magnetic fabric of the Toba Tuffs: Constraints on the sources and eruptive styles, Journal of Geophysical Research, 91, 10,355-10,382. LaBar, M.P., 2002, The Gas Turbine - Modular Helium Reactor: a promising option for near term deployment, General Atomics, GA-A23952. Lambert, R., 2005, A Basic Primer on Mine Design, Pincock Perspectives, Issue No. 69. Lewis, J.S., 1996, Mining the Sky: untold riches from the asteroids, comets and planets, Addison-Wesley, Reading, Massachusetts. NRC, 2006, Mine Mechanization and Automation, Natural Resources Canada. Schmitt, H., 2006, Return to the Moon, exploration, enterprise, and energy in the human settlement of space, Copernicus Books, New York, NY. Uranium Information Center (UIC), 2006, Small Nuclear Power Reactors, Briefing Paper No. 60. Wegeng, R., and Sanders, G.B., 2005, Lunar Resource Utilization, Executive Lunar Commerce Roundtable, Cox School of Business, Maguire Energy Institute, Southern Methodist University, Dallas Texas.

AUTHORS

John A. Chapman, B.Sc., FCIM, is a Professional Mining Engineer (British Columbia). He has worked 41 years in the mining industry in operations, engineering and as an executive. He has been instrumental in the development of several surface mines in Canada - some in adverse northern locations. He also has worked in heavy construction on the DEW line in the Canadian Arctic and is a proficient operator of most large mining equipment. Marc Schulte, B.Sc. is a Mining Engineer in Training (EIT, Alberta). He has worked five years in the mining industry as a surveyor, mine planner, and a heavy mobile equipment supplier. His mining experience has been in mountain coal and metal, prairie strip, oil sands and hard rock diamonds - all in Western and Northern Canada.

John A Chapman mining the moon 20060723

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