BUILDING AN ECONOMICAL AND SUSTAINABLE LUNAR INFRASTRUCTURE TO ENABLE HUMAN LUNAR MISSIONS

Allison Zunigaa*, Hemil Modib, Aurelio Kaluthantrigec, Heloise Vertadierd

aNASA Ames Research Center, Space Portal Office, Moffett Field, CA 94035, allison.f.zuniga@nasa.gov bScience & Technology Corp, NASA Ames Research Center, Moffett Field, CA 94035, [email protected] cInternational Space University, Strasbourg, France, [email protected] dInternational Space University, Strasbourg, France, [email protected] *Corresponding Author

Abstract To enable return of human missions to the surface of the Moon sustainably, a new study was initiated to assess the feasibility of developing an evolvable, economical and sustainable lunar surface infrastructure using a public- private partnerships approach. This approach would establish partnerships between NASA and private industry to mutually develop lunar surface infrastructure capabilities to support robotic missions initially and later evolve to full- scale commercial infrastructure services in support of human missions. These infrastructure services may range from power systems, communication and navigation systems, thermal management systems, mobility systems, water and propellant production to life support systems for human habitats. The public-private partnerships approach for this study leverages best practices from NASA’s Commercial Orbital Transportation Services (COTS) program which introduced an innovative and economical approach for partnering with industry to develop commercial cargo transportation services to the International Space Station (ISS). In this approach, NASA and industry partners shared cost and risk throughout the development phase which led to dramatic reduction in development and operations costs of these transportation services. Following this approach, a Lunar COTS concept was conceived to develop cost-effective surface infrastructure capabilities in partnership with industry to provide economical, operational services for small-scale robotic missions. As a result, a self-contained lunar infrastructure system with power, thermal, communication and navigation elements was conceptually designed to increase capability, extend mission duration and reduce cost of small-scale robotic missions. To support human missions, this work has now been extended to analyze full-scale lunar infrastructure systems. This infrastructure system should have capabilities to support human missions from a few days to several months with minimal maintenance and replacement of parts. This infrastructure system should also maximize the use of existing lunar resources, such as, oxygen from regolith, water from ice deposits at the poles, and use of metals, such as iron and aluminum, from lunar regolith. The plan includes a buildup of these capabilities using a phased- development approach that will eventually lead to operational infrastructure services. By partnering with industry to develop and operate the infrastructure services using the COTS model, this plan should also result in significant cost savings and increased reliability. This paper will describe the Lunar COTS concept goals, objectives and approach for developing an evolvable, economical and sustainable human lunar infrastructure as well as the challenges and opportunities for development.

Keywords: Lunar Exploration, Lunar Outpost, Lunar Surface

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1. Introduction enables global surface access on the moon, significant NASA is currently planning to send humans to the cislunar science and deep space technology Moon by 2024 under its new Artemis Program. The development as well as serve as an integrator and Artemis program takes its name from the twin sister of transfer hub where spacecraft can dock, assemble and Apollo and goddess of the Moon according to Greek embark to the lunar surface and other destinations. mythology, which aptly describes the program that is To reach the lunar surface, NASA plans to work planning to send the first woman and the next man to with commercial providers to develop a Human the surface of the Moon. The Artemis Program is a Landing System (HLS) [3] to transfer crew and two-phased approach to the Moon where the first payloads from the Gateway to the lunar surface and phase is focused on getting astronauts to the surface of then return crew and surface samples back to the the Moon as fast as possible, within 5 years by 2024. Gateway. It is expected that the crew will be flown to The second phase is focused on establishing a the Gateway in its NRHO and back to Earth in the sustained human presence on and around the Moon by Orion spacecraft, where the Gateway will be used to 2028. To accomplish these goals, NASA plans to support the transfer of crew and supplies into the HLS. launch astronauts atop the Space Launch System The HLS should include three stages: a transfer (SLS) and within the Orion spacecraft to a new lunar element for the journey from the Gateway to low-lunar orbiting platform called the Gateway [1], in the first 3 orbit, a descent element to carry the crew to the lunar Artemis flights as shown in figure 1. The initial surface, and an ascent element to return the crew to the configuration of SLS, for these first 3 flights, will be Gateway as shown in Figure 1. In addition, at the able to send more than 26 metric tons (mt) of crew and present time, NASA is accepting alternative cargo to Gateway and a planned future upgrade, called approaches from industry for the HLS that can Block 1B, will be able to send approximately 37 mt to accomplish the long-term goals of its Artemis orbits around the Moon [2]. program. The Gateway is planned to be a small orbiting NASA is planning to target the lunar south pole as spaceship with living quarters for astronauts and the first destination to land the first woman and the docking ports for visiting vehicles. The Gateway is next man on the surface of the Moon. The lunar south currently planned to be deployed in a highly elliptical pole was selected due to the recent discovery of seven-day, near-rectilinear halo orbit (NRHO) around potentially large amounts of lunar ice deposits in the the Moon, which would bring it to within 3,000 km at permanently shadowed regions (PSRs) and its closest approach and as far away as 70,000 km at surrounding areas [4]. Some studies have estimated its farthest. The Gateway will provide a platform that

Figure 1. NASA’s Planned Architecture Elements for the Artemis Program

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that the total quantity of water contained within the For these reasons, development of a surface uppermost meter of all the PSRs could be 2.9x1012 kg infrastructure using a public-private approach has (or 2900 million mt of water) [5], based on LCROSS been studied in this paper to provide economic mission results that also estimated concentrations of benefits to both NASA missions and the private sector water-ice at 5.6 + 2.9% by mass in the Cabeus crater business endeavors. The following sections will of the south pole [6]. Water from these ice deposits is describe the assumptions, approach, analysis and a very desirable resource for human missions as this findings as a result of this study. water can be used for human consumption, life- support systems, fuel cell generators as well as for rocket propellant production, such as liquid hydrogen and liquid oxygen, that can be used for fueling ascent vehicles. The lunar South Pole is also a highly desirable destination because of its “peaks of eternal light” which are defined as regions at high elevations and high latitudes that have extended periods of illumination. Although there are no regions on the Moon that are permanently illuminated, there are a series of closely located sites at the north and south poles that collectively receive solar illumination for Figure 2. Rim of Shackleton crater with stations that are predominantly illuminated approximately 93.7% of the year [7]. As an example, Shackleton crater was identified to contain three 2. Lunar COTS Concept locations that are independently and collectively Earlier versions of the Lunar Commercial illuminated for a majority of the lunar year. As shown Operations and Transfer Services (LCOTS) concept in figure 2, stations 1 and 2, which are located 1.8 km was previously outlined by Zuniga et al [9,10]. This from each other, were collectively illuminated for concept has been evolving as more studies and 86.9% of the year and stations 2 and 3, which are analyses are performed with the visionary goal of located 2.1 km from each other, were collectively achieving an industrialized lunar surface and healthy illuminated for 85.5% of the year. All three stations space-based economy to benefit NASA, industry and combined were illuminated for 92.1% of the year and the international space community. The LCOTS the longest period that all three were in shadow was 43 concept was based on the unique acquisition model hours. from NASA Johnson Space Center’s Commercial The collection of nearby stations with extended Orbital Transportation Services (COTS) program [11]. periods of illumination, such as along the rim of This program was very successful in developing and Shackleton crater, are highly desirable areas for demonstrating cargo delivery capabilities to the ISS in human exploration as they provide almost continuous partnership with industry. It was planned together with solar illumination and are adjacent to large PSRs the ISS Commercial Resupply Services (CRS) where there may be an abundance of lunar ice. These contracts which awarded SpaceX and Orbital Sciences regions are also of great interest to commercial Corp (now known as Orbital ATK) in 2008 to resupply providers who are developing business plans for a the ISS on a regular basis with unpressurized and commercial lunar propellant production facility [8]. pressurized cargo. As a result of the COTS and CRS Studies have shown that creating propellant from programs, two new launch vehicles and spacecraft water may be a very lucrative business and may be the were developed and have been successfully servicing first step in creating a vibrant cislunar economy. the ISS program since 2012 with cargo transportation Sowers [8] also cites that if such surface infrastructure missions: 1) SpaceX’s Falcon 9 launch vehicle and can be leveraged then this may dramatically lower the Dragon spacecraft; and 2) Orbital’s Antares launch cost to both public and private activities on the surface. vehicle and Cygnus spacecraft. Recent studies have

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shown that government funding investments provided and self-contained lunar infrastructure system was less than one half of the cost for these two commercial conceptually designed to operate on the lunar surface transportation systems (47% government funding for and provide power, thermal control, communication, SpaceX and 42% government funding for Orbital) navigation and mobility services throughout the lunar [11]. Also, it has been estimated that the final day and night. For example as shown in figure 3, this development cost for SpaceX’s Falcon 9 rocket was infrastructure system or power-tower design was about $400M which is approximately 10 times less based solely on solar power and recently space than projected costs of approximately $4B for the qualified lithium-ion batteries to avoid the high costs same rocket using traditional cost-plus contracting and safety concerns of radioactive systems, such as methods [12]. radioisotope heating units (RHUs) or radioisotope The key to the huge success of the COTS program thermo-electric generators (RTGs). The power-tower can be primarily attributed to its unique acquisition design provided a low-cost, high technology readiness model which was developed in 2005 together with the level (TRL), high-reliability design that resulted in program plan. At the time, it was desired to enter into providing sufficient power to recharge and thermally partnership agreements with industry teams to develop hibernate small rovers and other critical equipment new space transportation capabilities and services during the lunar night. This design was equipped with where both parties had ‘skin in the game’ in terms of a 10-meter communication tower to provide expanded both sharing cost and risk. It was also important to communication links between the lunar surface and incentivize industry to capture new commercial Earth and local lunar communications along with markets and not solely rely on NASA as the customer. navigation system to rovers for enhanced autonomous For this new acquisition method, NASA’s Other operations. Initial estimates showed that the power- Transaction Authority (OTA) through the Space Act tower design could extend mission duration of robotic was examined to create a mechanism to invest missions from a few days to 6-8 years and increase resources into the industry partners for development of traverse distances from a few meters to hundreds of these commercial capabilities for mutual benefit. As a kilometers for the same cost of a nominal mission. result, the COTS program office elected to use Funded Space Act Agreements (FSAAs) in their acquisition strategy. The FSAAs were structured to allow much more flexibility to the industry partner with less insight and oversight from NASA, allowing for innovation without being encumbered with the full administrative and reporting requirements traditionally required by FAR contracts. However, this approach also offered more risk which has been addressed by NASA Policy directives, Space Act Agreements Guide [13] and Space Act Agreements Best Practices Guide [14]. This new acquisition approach or model was used as the basis for the Lunar COTS (or LCOTS) Figure 3. Power-Tower Conceptual Design conceptual study. The goal for this study was to develop a plan based on the COTS model to partner Although the power-tower design was developed with industry to develop new capabilities for the lunar to support small-scale robotic missions, it showed the surface for mutual benefit as well as to stimulate new feasibility of reducing cost while increasing mission commercial markets to grow a new space-based performance and reliability to enable sustainable and economy. Toward this end, development of a small- long-term robotic missions. To determine if this scale, lunar infrastructure system for small robotic concept could be applied to large-scale missions to missions was studied and analyzed to benefit both reduce costs for human missions, the LCOTS concept NASA and its commercial space partners. As a result was expanded to study development of large-scale of this study [15], a multi-functional, multi-purpose infrastructure systems in support of human and other

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large-scale missions. This work is described in the By taking advantage of this phased development three-phase development approach for LCOTS as approach in partnership with industry, the benefits to outlined below. NASA would be reduced development costs and risk Figure 4 shows the three-phase approach for the as well as cost-effective commercial products and LCOTS concept. This approach allows for incremental services to accomplish its science, robotic and human development and demonstration of lunar surface missions. The benefits to industry would be shared capabilities and services from small-scale to human technical expertise as well as shared development scale. As shown in Figure 4, the Phase 1 objectives costs to help raise private capital, implement new were focused on developing infrastructure capabilities business plans and lower risk to capture lunar markets, to support small-scale robotic missions. The power- such as lunar mining and lunar tourism, opening a tower concept as previously described was developed new frontier. to meet these Phase 1 objectives. 3.0 ISS as an Analog for Lunar Outpost Phase 2 objectives focus on developing pilot-scale feasibility missions to demonstrate infrastructure ISS is humanity’s only international orbiting capabilities to support human habitats and large-scale platform enabling multidisciplinary scientific and commercial activities, such as lunar propellant technological research along with expanding our production. The purpose of these missions would be to knowledge and understanding of the human body, our demonstrate these capabilities and evaluate the planet and space. It is also a habitat for 6-9 astronauts, technical feasibility and economic viability of scaling providing suitable environmental conditions for long up the infrastructure services for full-scale operations duration stay and necessary systems to perform in support of the human missions. research and investigations in the field of life sciences, Phase 3 of the Lunar COTS concept, as shown in human health and physiology along with studying the Figure 4, would make long-term awards to long-term effects of space travel. ISS provides commercial providers for infrastructure services, such multipurpose internal and external facilities which are as, power, communications, habitats with life support modular and whose design specifications are publicly systems, etc. The decision to make these awards would available for anyone around the world to perform be contingent on the level of success of the pilot-scale research and experiments in space. It’s this open feasibility missions. This approach is very comparable architecture which allows the numerous international to the COTS program where the technical and commercial partners involved with ISS to perform demonstration missions informed the decision to a diverse set of activities, such as, enabling award long-term ISS cargo delivery services. fundamental research in space to benefit life on earth.

Figure 4. LCOTS Phased-Development Approach

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ISS is a testament of successful international 3.2 ISS Specifications collaboration and cooperation to develop a modular, 3.2.1 Mass and Volume: The ISS is 357 feet end to adaptable and open architecture platform. With the end, has a mass of 925,335 pounds (419,725 experience and expertise garnered over years of kilograms), habitable volume of 13,696 cubic feet research and development with ISS, it is the perfect (388 cubic meters) not including visiting vehicles, analog model for designing the next generation lunar pressurized volume of 32,333 cubic feet (916 cubic infrastructure to support a long-term, human lunar meters). It has a living and working space which outpost. includes 6 sleeping quarters, 2 bathrooms, a gym and The following subsections provide description of a 360 degrees observatory call cupola. It currently the space environment and basic subsystems of the ISS holds a permanent crew of 6 astronauts all year round. which can be used as an analog for lunar infrastructure [18] systems development to support a lunar outpost and enable a sustained human presence on the Moon. 3.2.2 Power: Its 240 feet wingspan solar array provides 75 to 90 kilowatts of power. The 27,000 3.1 Space environment in Low Earth Orbit: square feet of solar panels and their 262,400 solar cells Space is a very harsh environment with temperature generate power necessary to operate the station and is variation from 120 deg C to -120 deg C, hard vacuum stored in Nickel Hydrogen batteries (currently being of 10-6 to 10-9 torr, 425 μSv/d ionizing radiation, replaced by Lithium Ion batteries [19]) to provide micrometeoroids, orbital debris, ionospheric plasma uninterrupted power supply at 124V including during and < 1 μg (quasi-steady level) microgravity among eclipse time. [20] other effects [16,17]. In order to provide a safe and 3.2.3 Communication: The Russian Orbital Segment comfortable environment for astronaut habitation it is uses a Lira high-bandwidth antenna to communicate important to understand the external environmental directly with ground, while the US orbital segment conditions and develop appropriate mitigation uses two separate radio links in S band and Ku band. strategies where necessary. The following table lists UHF radios are also used by astronauts and some of major environmental threats to the ISS and its cosmonauts during the EVAs. In order to ensure mitigation strategies. constant communication with ISS, data is Table 1. Major threats with the corresponding communicated to Earth using a series of ground-based mitigation strategy undertaken at the ISS. antennas called the Space Network and a system of Tracking and Data Relay Satellites (TDRS). ISS also Threat Mitigation strategy has a Ham Radio. NASA is also gearing up to test laser - Shielding critical elements to protect communication on ISS in the near future. [21] Micro- from <10 cm objects 3.2.4 Environmental Control and Life Support Systems meteoroi - Performing collision avoidance (ECLSS): The ISS has redundant environmental ds and maneuvers to protect from >10 cm orbital objects control and life support systems in the US and Russian debris - Implementation of design features and side which provide air revitalization, oxygen operational procedures generation, water recycling, temperature and humidity control for the pressurized sections of the ISS. The air Extreme Thermal control on spacecrafts and pressure and constituents inside ISS are similar to tempera- spacesuits, active and passive heating Earth and at about 101.3kPa (14.69 psi). tures and cooling systems 3.2.5 Water, Oxygen and Food requirements: An Radiation Spacecraft shielding (water shelters, astronaut needs 0.84 kg of oxygen and a maximum of polyethylene), onboard radiation 2.68 kg and 25.95 kg of water for metabolic and dosimeters hygienic purposes per day. [22] The water recovery system on the US segment generates 12.7 kg/day potable water providing the daily requirement

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equivalent for about 4.73 individuals with an overall solar wind, the solar flare associated particles (solar efficiency of 88%. energetic particles) and the galactic cosmic rays. Most of the oxygen on ISS is produced by Radiation interacts with the surface of the Moon in electrolysis of water by the oxygen generation system different ways and depending on the energy and in the US segment and the Elektron in the Russian composition result in varying penetration depths from segment. The Russian segment also has a solid fuel micrometers to meters. These interactions can also oxygen generation system called Vika. The oxygen generate secondary neutrons and gamma rays. The generation system in the US segment produces oxygen amount and type of radiation also poses a larger threat at an average daily rate of 2.34 kg/ day corresponding to humans than what is experienced on Earth and to the daily requirement equivalent of about 2.78 within the ISS. individuals. The ISS also uses a Sabatier system to 4.1.3 Extreme Temperature: The Moon experiences produce water and methane from carbon dioxide and approximately 14.77 days of sunlight followed by hydrogen which are both byproducts of the life support 14.77 days of darkness due to its synodic period of system on ISS. approximately 29.5 days. This approximate 14 The food requirement on the ISS is 0.83 kg per day/night cycle presents unique engineering meal per crew member. This paramount need is being challenges as surface experiences extreme temperature fulfilled solely by resupply missions. [23] changes from approximately 120 deg C in the daylight

to -180 deg C at night. Surface temperatures at the 4. Lunar Infrastructure Systems for Sustained Human Presence on the Lunar Surface poles are even colder reaching approximately -258 deg This section describes the infrastructure or surface C due to the very low incidence angle of the sunlight. systems necessary to enable a long-term outpost for At these extreme temperatures, most electronics and sustained human presence on the lunar surface. The spacecraft subsystems, such as batteries, transponders assumptions made in this analysis included: 1) use of and solar panels will freeze and become inoperative. the ISS subsystems as a basis for analysis; 2) a 4.1.5 Dust: Apollo missions have taught us a lot about sustainable human presence for 6 astronauts; 3) the characteristics and properties of lunar regolith mission durations of up to 30 days; and 4) use of lunar dust. It mostly has an average grain size between 45 resources as much as practicable to reduce mass and µm to 100 µm. The grains are sharp, glassy, have cost of cargo to be delivered from Earth. extremely low electrical and dielectric losses allowing 4.1 Environment: Establishing infrastructure to sustain electrostatic charge to build up under UV radiation. a 6-member crew for a 30-day mission duration, raises Micrometeoroids impacting on the lunar surface are issues related with the harsh environment of space and the source of a persistent tenuous clouds of dust grains. distinct environmental characteristics of the Moon. While designing systems for the Moon it is important to address the following properties of the lunar dust: The following subsections outline the properties and challenges posed by these characteristics. 1) abrasiveness to friction bearing surfaces, EVA suits 2) pervasive nature on seals, gaskets, optical lens, 4.1.1 Gravity: Average gravity on the Moon is 1.62 windows, 3) gravitational settling on thermal and m/s2, about 1/6th of the Earth’s gravity. Low gravity optical surfaces like solar cells and 4) physiological reduces the energy required to propel from the surface effects on the human lung tissue. Lunar dust can be of the Moon. The effects of long duration partial managed/mitigated by abrasion resistant coatings; gravity on human physiology are still to be coatings that repel dust; vibration, electrostatic, determined. magnetic, brush and vacuum cleaning systems, electrodynamic dust shield, plasma-based dust 4.1.2 Radiation: Unlike Earth, the Moon has a sweepers etc. [24, 25] significantly weaker atmosphere (14 orders of magnitude lower than the Earth’s atmosphere) and 4.2 Infrastructure Development and Guidelines negligible magnetic field which does not provide The following subsections describe recommended enough protection from radiation. Lunar radiation is guidelines for infrastructure development of an characterized by three kinds of ionizing radiation: the outpost for sustained human presence on the lunar

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surface. These subsections also describe mitigation structure providing internal environment similar to strategies that can be implemented to overcome the ISS. The habitat air locks should also be able to challenges of the lunar environment as described in the remove the lunar dust particles and provide air quality previous subsections. similar to acceptable air quality index with particulate matter 2.5 and 10 at 35 μg/m3 and 150 μg/m3 over a 4.2.1 Power: The outpost should be capable of 24-hour exposure period. [29] generating enough energy required to power the In order to conduct operations, the ISS offers 916 habitation modules, the scientific experimentation meters of pressurized volume including 388 cubic modules along with charging rovers and exploration meters of habitable volume. The Minimum Acceptable equipment. Using ISS as an analog system, a goal of Net Habitable Volume defined as "the minimum 75-90 kilowatts should be sufficient for a lunar volume of a habitat that is required to assure mission outpost. There are several options for generating this success during exploration-type space missions with power including solar power systems, regenerative prolonged periods of confinement and isolation in a fuel cells and nuclear power systems. Due to almost harsh environment" is 883 cubic feet per person (i.e.25 negligible atmosphere, efficient ground and space- cubic meters) [30]. Hence for a crew of 6 on the Moon based power beaming concepts could also be the minimum pressurized habitable volume should be implemented helping connect power generation sites at least 150 cubic meters along with areas for personal to exploration areas. hygiene and exercise. 4.2.2 Communication: Constant and high-speed To meet these needs and challenges, an inflatable communication is a key enabler for mission operations habitation system could provide habitat units more at scale. NASA’s LADEE spacecraft demonstrated 40- durable with greater volume and less mass than rigid 622 Mbit/s downlink and 10-20 Mbits/s uplink from modules. Since the inflatable structure is collapsible, lunar orbit to Earth and vice versa using laser it can be produced in virtually any shape and can be communications [26]. Hybrid Optical and radio wave packaged for launch more efficiently. Bigelow communication system (e.g. S, X, KU, KA and UHF) Aerospace is one commercial provider that has been coupled with data relay satellites and mesh networks studying the design of inflatable structures for space for ground communications between astronaut- and the lunar surface for a number of years. Their astronaut, astronaut-robot/rover, between outpost and inflatable structure concept, as shown in Figure 5, can exploration crew, equipment and Moon to Earth would accommodate up to 6 people for 120 days and provides provide a robust and reliable communications an interior volume of 330 m2 which would include 6 architecture. [27] large crew quarters, a large amount of storage 4.2.3 Navigation: Reliable and precise navigation on capacity, 2 toilets and 2 galleys [31]. In addition, to Earth is an almost solved problem due to systems like protect the crew from harmful radiation or the Global Positioning System satellites and ground micrometeorite debris, the inflatable structures could based Differential GPS units. Having a reliable be covered with regolith or placed within a lunar cave navigation solution on the Moon would be another key or lava tube. Passive radiation shielding is another enabler for infrastructure development leading to a option that can be provided using water walls or trash lunar outpost. Systems like star trackers, image based recycled polyethylene while electrostatic and positioning systems, small satellite constellation and magnetic field can provide active shielding. [32] potentially using GPS on the surface of the Moon can provide the necessary foundation for a dependable navigation solution on the surface of the Moon. [28] 4.2.4 Habitation: The outpost will require pressurized modules with standard interface mechanism similar to the International Docking Adapter on the ISS for habitation and scientific exploration along with air locks at entry and exit points. The habitat should provide a radiation and micrometeorite resilient

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propellant production. Methane can also be produced using pyrolysis of plastic trash and crew waste with in- situ oxygen. Extreme temperature differentials close to the lunar poles also opens up possibilities to develop novel thermoelectric systems for power generation and habitat/equipment heating and cooling. Once initial investigations are complete and candidate procedures/technologies have been identified then ISRU products can replace the Earth-based systems gradually to reduce the number of re-supply missions from Earth. [35] 4.3 Outpost Site Selection: The location of the lunar outpost should be mainly driven by the availability, Figure 5. Example of Bigelow’s Inflatable Habitat amount and accessibility of resources, environmental challenges, engineering development, cost, 4.2.5 Environmental Control and Life support systems, operational considerations and scientific potential. As Oxygen, Water and Food requirements: The lunar previously discussed, the lunar poles offer sites with outpost can commence operations using electro- highly-elevated regions and extended periods of mechanical life support systems from Earth similar to illumination or “peaks of eternal light” near ISS with eventual goal of replacing it with bio- permanently-shadowed regions, such as the rim of the regenerative life support systems starting with local Shackleton crater at the south pole. Such locations food production. Based on ISS data, the amount of provide near constant access to sunlight which will resources needed per day that shall be provided for the enable low-cost, continuous, year- round solar power sustainment of 6 astronauts for a 30 day mission on the generation. The temperatures at these peaks of eternal Moon is approximately: 151.2 kg of oxygen, 482.4 kg light are also near constant which would reduce the of potable water, 4671 kg of water for hygiene and engineering challenges of designing for extreme 448.2 kg of food for 3 meals per day. A highly efficient temperature changes at equatorial sites. Also the ECLSS system like the ISS with an oxygen generation permanently shadowed craters at the lunar poles may system and water recycling system should be able to contain large quantities of water-ice that can be used recover 70.2 kg of oxygen and 381 kg of potable water for human consumption, life support systems and for a 30-day mission, reducing the amount of propellant production. For all these reasons, it is resources required from Earth. Placing the habitats recommended that these peaks of eternal light be near the lunar poles may also provide ease of access to considered as a primary option for reducing the the potential water-ice deposits, helping make the engineering challenges, complexity and cost in system more earth independent. development of a long-term, lunar outpost. For bio-regenerative life support systems a crop production area of 28 m2 to 40 m2 would be required 5.0 Potential Commercial Lunar Services to generate 100 % oxygen and 50 % caloric intake per As previously discussed, the Artemis program’s crew member. A 240 m2 crop production area would second phase is focused on establishing a sustained provide all the oxygen and 50% caloric intake for a 6- human presence on and around the Moon by 2028. To member lunar crew. [33, 34] develop a plan that can achieve a sustained human presence, it is important to first understand the 4.2.6 In-Situ Resource Utilization (ISRU): The lunar parameters necessary for sustainability. According to outpost can be established using Earth-based systems the United Nations Brundtland Commission, with a rapid, iterative test and development plan to sustainability is defined as “meeting the needs of the enable ISRU by investigating oxygen production from present without compromising the ability of future regolith, extracting water-ice from permanently generations to meet their own needs” [36]. According shadowed craters and splitting water into oxygen and to the World Commission of Environment and hydrogen for life support, energy generation and

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Development, sustainable development is defined as of the infrastructure. Similar to industrialization “the process of change in which the exploitation of efforts of the past, government can be a catalyst to resources, the direction of investments, the orientation lunar industrialization by partnering with industry to of technological development and institutional change build the infrastructure needed for new lunar are all in harmony and enhance both current and future businesses to succeed and a new space economy to potential to meet human needs and aspirations.” To set emerge. metrics of sustainable development for the Moon, a As outlined in the previous section, there are a study by the International Space University developed number of infrastructure systems or utility services fifteen Lunar Sustainability Goals to ensure that necessary to support a sustained human presence on proposals for future lunar missions are feasible and the lunar surface. Most of these utility services will sustainable for the long term [37]. Through study of also be needed by industry to accelerate their business these references, a plan to achieve a sustained human plans and lead to a positive return on investment. presence should include: 1) an architecture or lunar These utility services of common interest include outpost that provides the basic systems necessary to power generation and storage, communication and sustain human life and which mitigates the navigation systems, water and propellant production. environmental threats that were outlined in the Therefore, it will be advantageous for NASA to previous section; 2) a sustainable economic plan that partner with private industry using the COTS approach yields short-term technological advantages for Earth- to jointly develop these capabilities. The following based and lunar-based products and long-term return- subsections describe some examples of these on-investments; and 3) in-situ use of lunar resources capabilities and potential partnerships for while preserving the lunar environment. development. To meet these objectives, this evolution of the Lunar COTS concept aims to leverage public-private 5.1 Power Generation and Storage partnerships to jointly develop cost-effective, surface Discussion from the previous section presented infrastructure capabilities that will lead to economical, the guidelines for power generation for a lunar outpost commercial lunar services in support of human within the range of 75-90 Kilowatt, similar to ISS. missions. The key to successful partnerships is finding There are several options for generating this power common areas of interest that will yield mutual including solar power systems, regenerative fuel cells, benefit. For partnerships with private industry, there nuclear power systems and wireless power beaming. are several potential lunar industries that have been The key to selecting the appropriate power system identified that may yield substantial economic benefits depends on the environmental challenges of the lunar for both NASA and industry. These industries range outpost site. For equatorial sites, there will be 14 days from lunar mining, manufacturing, propellant of sunlight followed by 14 days of darkness with large production, communication satellites, space-based temperature changes from 120 deg C to -180 deg C. solar power to lunar tourism. It is believed that these For solar power systems, these environmental industries may lead to a multi-trillion dollar, space- conditions require long-term energy storage solutions, based economy in the next three decades drawing such as batteries. The challenge of using batteries interest from plenty of private companies and include the addition of thermal management using investors to develop business plans to capture these heaters for cold conditions and radiators for hot markets [38]. These markets, if fully or partially conditions. The number, size and mass of the battery developed, will undoubtedly reduce the overall cost system will also be dependent on the overall design of and enable sustainability for a long-term human the mission. For a 30-day human mission, batteries presence on the lunar surface. may not be a practical and cost-effective option at The challenge to these private companies is the equatorial sites, but they may be beneficial for polar size of investments needed upfront to put in place all missions. the elements of the infrastructure needed to make their Another option to overcome the long lunar nights business plans successful. This is where government may be nuclear power stations but they present many can help to offset this economic burden from the other challenges such as potential radiation hazards to individual businesses and help with the development humans and equipment as well as safety and

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environmental concerns on launch. A recent NASA development effort, named Kilopower, includes a sterling-based generator that can produce 1 kilowatt of electric power with a system mass of 400 kilograms. The Kilopower concept is designed to use highly enriched uranium fuel. This design can be scaled up to 10 kilowatts with a system mass of 1500 kilograms. There are also advanced plans to explore use of a commercial low-enriched uranium fission reactor system concept that is predicted to be able to provide from 10 kilowatts to one megawatt electric power. Due to the hazardous nature of radioactive sources and amount of development time needed, nuclear options Figure 6. Lunar Surface-Based Space Solar Power are also not the most practical and cost-effective Preferred Option from Mankins [39] option for 2028 timeline. To avoid the challenge of developing a low-cost, 5.2 Water and Propellant Production low-mass system that can operate through the 14 days Another large market attracting interest from of lunar night, an attractive option is selecting a site in private industry and investors is lunar-derived one of the regions that have extended periods of propellant. A recent collaborative study [40] led by illumination. As described earlier, the lunar south pole ULA and other experts from industry, government and has a few regions with a series of closely located sites academia examined the technical and economic that collectively provide solar illumination for feasibility of establishing a commercial lunar approximately 93.7% of the year. The one region propellant production capability. A wide range of mentioned earlier was Shackleton crater in the south customers for propellant were identified including the pole. If a lunar outpost were to be built in one of these commercial launch industry (ULA, SpaceX, Blue regions, a cost-effective solution for generating power Origin, etc) for refueling in LEO and GEO, would be photovoltaic (PV) solar arrays. PV solar government space agency transportation systems arrays are a space-proven technology and can provide (NASA, ESA, etc) for use on the lunar surface (for sufficient power required for this size lunar outpost, fueling up ascent vehicles), or cislunar space (fuel around 75-90 kW. depot at Gateway or Lagrange points) or interplanetary In addition to the PV arrays, power beaming can space (missions to Mars and beyond). With the be used in combination with this system to wirelessly development of plans for sustained human presence on transmit power to receivers located in the permanently or in orbit around the Moon, additional markets can shadowed regions of craters. It would be very also emerge for oxygen and water to support human advantageous and cost-effective to beam power into habitats, life support systems and other systems, such these dark regions for use in extraction of water-ice as, regenerative fuel cells for power generation, resources. Mankins [39] studied this specific option, thermal management and radiation shielding systems. named Lunar Surface-Based Space Solar Power, and As a result of the potential market demand, the study showed very promising results. As shown in figure 6, identified a near-term annual demand of 450 tons of Mankins’ preferred architecture option was able to lunar-derived propellant delivered to various beam power in the range of 100 kW to distances in the locations, equating to 2450 metric tons of processed range of 40 to 50 km. His analysis also showed lunar water. hardware costs of less than $100M to deliver 100 kW This study also reviewed the approach, challenges which was an order of magnitude less than the cost of and payoffs for an architecture that can harvest and a nuclear power system for the same amount of power process lunar ice from within the PSRs at the lunar delivered. This business case offers a good example of poles to produce large amounts of water necessary to a very practical and low-cost architecture that can be meet the demands of the propellant market. To reach developed in partnership with industry to produce a these water-ice deposits, past studies have developed cost-effective, long-term, commercial utility service. architectures that include large and heavy machinery

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to excavate, drill and haul tons of lunar regolith to obtain the water-ice. These studies resulted in excessive costs which made it very challenging to close the business case. In contrast, a recent study focused on a revolutionary concept [41] to extract water-ice by using a lightweight capture tent and heating augers to sublimate the ice and transport the water vapor through the surface. As shown in Figure 7, the vapor is captured by a dome-shaped tent covering the heated surface and vented through openings into Cold Traps

(CTs) outside the tent where it refreezes. Once the CTs Figure 7. Capture Tent Concept for sublimating ice are full of refrozen ice, they are removed and replaced from lunar surface from Dreyer [41] with empty CTs. The ice-filled CTs are transported to a central processing plant for refinement into purified water, oxygen or liquid oxygen (LOX) and liquid hydrogen (LH2) propellants. Using this concept, Sowers [42] developed a business case for mining propellant on the Moon. For this analysis, the demand side of the business case was solely specified by ULA requiring 1100 mt of propellant purchased on the lunar surface for $500/kg. The Capture Tent concept was used for the production side of the business case with an estimated cost of $2.5 billion for development, fabrication and delivery to the lunar surface. As shown in Figure 8, this business case analysis resulted in $550M of revenue per year Figure 8. Propellant Production business case analysis generating a 9% return-on-investment and $2B in from Sowers [42] profit over the life of the project of 15 years. Figure 8 also shows another business case that 5.3 Keys to Successful Partnerships Using an LCOTS Approach included an additional propellant demand and As shown in the previous examples, there is a much investment by NASA through a public-private to be gained by leveraging public-private partnerships partnership. In this scenario, it was assumed there to develop new capabilities and services for mutual would be an additional demand of 100 metric tons benefit. These partnerships can accelerate NASA’s (mT) of propellant annually by NASA to fuel lunar progress in developing economical and sustainable landers for ascent from the Moon. The propellant price lunar infrastructure to obtain its goal for sustained was kept at $500/kg while NASA’s investment in the human presence on the Moon by 2028. Similarly, mining operation was assumed to be $800M. In this these partnerships can accelerate industry’s progress case, the return-on-investment increased to 16% with in establishing new lunar industries to provide services profits topping $3B over the life of the project. The to multiple customers for economic gain. However, analysis also showed that NASA’s initial investment before entering into partnership agreements using an resulted in a savings of $2.45B the first year, and LCOTS approach, a careful assessment should be $3.45B each year if the propellant cost remains at performed to determine the likelihood of success of $500/kg compared to delivering 100 mT of propellant these partnerships to develop the specified capabilities from Earth at a cost of $3.5B/year. in a certain timeframe. Some important factors to

consider during this assessment are: 1) number of viable companies with enough technical and financial capability and strong interest to pursue LCOTS

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opportunity; 2) size of potential markets likely to the LCOTS plan as described shows the potential for emerge within 5 years to attract private investors; 3) significant cost savings and risk reduction in the level of affordability to fully develop capability within development of a human lunar outpost. realistic budgets from NASA and private capital from In studying the needs and challenges of a lunar industry; 4) strong potential for positive return on outpost, the ISS was examined and used as an analog investment based on sound business plans; and 5) for a long-term, self-sufficient habitat in a space strong potential to reduce technical, cost or operational environment. With the experience and expertise risk towards an economical and sustainable lunar garnered over years of research and development with infrastructure. ISS, it was chosen as a very fitting analog model for In addition to performing this assessment, another designing the next generation lunar infrastructure to key factor, for an LCOTS approach to be successful, support a long-term, human lunar outpost. A review of is committing to long-term awards of several years for the ISS subsystems was presented along with a commercial services. This commitment to be an description of the environmental challenges and the anchor customer is essential for industry to raise mitigation strategies that are in place to overcome private capital by reducing the risk to investors and these challenges. setting achievable timelines in place. This approach A high-level analysis of the infrastructure systems also reduces risk to NASA by ensuring the industry needed to enable a long-term, sustainable human partners will be able to deliver its products and outpost on the lunar surface was also presented. The services on time and on schedule. To further reduce environmental challenges as well as the threats it may risk to NASA, long-term awards should be made to impose on the human lunar outpost were also multiple commercial providers to enable competition reviewed. As a result of the analysis, guidelines for and withstand interrupted services. Phase 3 of the the principle infrastructure systems were LCOTS phased-development approach (see Figure 4) recommended along with mitigation strategies to sets out to meet all of these objectives. overcome the environmental threats. To reduce all the environmental threats and produce low-cost, 6. Summary economical infrastructure systems, it was recommended that the outpost be located at one of the A new study was initiated to examine the highly-elevated stations with extended periods of feasibility of developing economical and sustainable illumination near permanently-shadowed regions, lunar surface infrastructure capabilities and services in such as the rim of the Shackleton crater at the Lunar partnership with industry to meet the goals of NASA’s South Pole. Such locations provide near constant Artemis program for a long-term, sustained human access to sunlight which will enable continuous, year- presence on the lunar surface by 2028. This work is an round solar power generation which would extension of the Lunar COTS concept [9,10] significantly reduce the cost of power generation and previously developed to leverage best practices from storage systems. The temperatures at these stations are NASA’s Commercial Orbital Transportation Services also near constant which reduces the need for complex (COTS) program which introduced an innovative and and costly thermal management systems. The nearby economical approach for partnering with industry to permanently shadowed craters may contain large develop commercial cargo transportation services to quantities of water-ice deposits that can be extracted the ISS. Following this COTS model, a Lunar COTS and used for human consumption, life support systems concept was conceived to develop cost-effective and propellant production, thus further reducing the surface infrastructure capabilities in support of small- overall cost of the human lunar outpost. scale robotic missions which has now been extended Finally, to assess the economic feasibility of the to support human missions. This concept included a LCOTS approach, several business cases were buildup of these capabilities using a phased- examined for potential partnerships, common areas of development approach as discussed that will interest with NASA and level of maturity to eventually lead to operational infrastructure services. successfully develop lunar surface capabilities for By partnering with industry to develop and operate mutual benefit. Several important factors were lunar infrastructure services using the COTS model, reviewed to determine the likelihood of success of

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these partnerships to develop specified capabilities in [6] A. Colaprete, P. Schultz, J. Heldmann, (et al), a certain time frame under an LCOTS approach. Two Detection of Water in the LCROSS Ejecta Plume, business cases were highlighted for power generation, SCIENCE Journal, Vol. 30, No. 6003 (2010) pp. 463- 468 water and propellant production as excellent examples [7] E.J. Speyerer, M.S. Robinson, Persistently of mature business plans where NASA can benefit by illuminated regions at the lunar poles: Ideal sites for partnering together with industry to develop future exploration", Icarus, 222, No. 1 (2013) pp. economical infrastructure capabilities and services to 122–136 meet its objectives for a sustained, human lunar [8] G. Sowers, Closing the business case of lunar presence. Both of these business cases showed propellant, Center of Space Resources, Colorado potential for a large customer base, low development School of Mines, 12 June 2018 [9] A. Zuniga, D. Rasky, R. Pittman, (et al), Lunar costs, high revenue and return-on-investment based on COTS: An Economical and Sustainable Approach to projected markets. The LCOTS phased-development Reaching Mars, AIAA Paper 2015-4408, AIAA approach can be used to take advantage of this interest Space Conference, Pasadena, CA, 2015 and enter into partnerships with these viable and [10] A. Zuniga, M. Turner, D. Rasky, (et al), interested industry partners to co-develop and Kickstarting a New Era of Lunar Industrialization via demonstrate these capabilities at pilot-scale on the Campaigns of Lunar COTS Missions, AIAA Paper lunar surface. Once these surface missions 2016-5220, AIAA Space Conference, Long Beach, CA, 2016 demonstrate technical and economic viability of these [11] NASA, Commercial Orbital Transportation capabilities, long-term awards can be made for Services – A New Era in Spaceflight, National purchase of commercial services, such as power Aeronautics and Space Administration, NASA SP- generation, water and propellant production. Both 2014-617, 2014 NASA and private industry can benefit from the [12] NASA Associate Deputy Administrator for LCOTS approach as it is designed to reduce cost and Policy, Falcon 9 Launch Vehicle NAFCOM Cost Estimates, August 2011 risk to both parties as well as accelerate timelines for [13] NASA Space Act Agreements Guide, NASA development which should result in large, economic Advisory Implementing Instructions, NAII 1050-1C, gains for industry and enable a long-term, sustainable 25 February 2013 human presence on the lunar surface. [14] NASA Funded Space Act Agreement Best Practices Guide, Human Exploration and Operations References Mission Directorate, 17 June 2015 [1] J. Crusan, Lunar Exploration Campaign: [15] A. Zuniga, M. Turner, D. Rasky, (et al), Development of the Lunar Orbital Platform-Gateway Building an Economical and Sustainable Lunar and Establishing the cislunar and surface architecture, Infrastructure to Enable Lunar Industrialization, IAC-18,A5,1,1,x46798, 69th International AIAA Paper-5148, AIAA Space Conference, Astronautical Congress, Bremen, Germany, October Orlando, FL, 2017 1-5, 2018 [16] M. Finckenor, K. de Groh, A researcher’s guide [2] NASA website, Space Launch Systems Lift to: International Space Station - Space environmental Capabilities, effects, NASA ISS Program Science Office NP- https://www.nasa.gov/sites/default/files/atoms/files/sl 2015-03-015-JSC (2015) s_lift_capabilities_and_configurations_508_0820201 [17] R. Thirsk, A. Kuipers, C. Mukai, D. Williams, 8_0.pdf, (accessed 29.09.19) The space flight environment and beyond, CMAJ [3] E. Mahoney, NASA seeks input from U.S. 180(12): 1216–1220 (2009) Industry on Artemis lander development, 30 August [18] NASA website, International Space Station facts 2019, https://www.nasa.gov/feature/nasa-seeks- and figures, 21 March 2019, input-from-us-industry-on-artemis-lander- https://www.nasa.gov/feature/facts-and-figures, development, (accessed 29.09.19) (accessed 29.09.19) [4] P.D. Spudis, D.B.J. Bussey, S.M. Baloga (et al), [19] JAXA website, HTV6 Payload, 2 December Evidence for water ice on the Moon: Results for 2016, http://iss.jaxa.jp/en/htv/mission/htv- anomalous polar craters from the LRO Mini-RF 6/payload/, (accessed 29.09.19) imaging radar, Journal of Geophysical Research: [20] M. Garcia, About the Space Station solar arrays, Planets, Vol. 118, 2016-2029 (2013) 4 August 2017, [5] I. Crawford, Lunar Resources: A Review, https://www.nasa.gov/mission_pages/station/structur Progress of Physical Geography (2014)

Page 14 of 15

e/elements/solar_arrays-about.html, (accessed Space Research, Vol. 42, Issue 6 (2008) pp. 1043- 29.09.19) 1049 [21] L. Jenner, NASA engineers tapped to build first [33] R.M. Wheeler, Carbon balance in integrated photonics modem, 29 January 2016, bioregenerative life support systems: Some effects of https://www.nasa.gov/feature/goddard/2016/nasa- system closure, waste management, and crop harvest engineers-tapped-to-build-first-integrated-photonics- index, Advances in Space Research, Vol. 31, Issue 1 modem, (accessed 29.09.19) (2003) pp. 169-175 [22] H. Jones, Design Rules for Space Life Support [34] G. Bosheri, M. Kacira, L. Patterson, (et al), Systems, 2010, Modified energy cascade model adapted for a https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/2 multicrop Lunar greenhouse prototype, Advances in 0040012725.pdf, (accessed 23.08.19) Space Research, Vol. 50, Issue 7 (2012) pp. 941-951 [23] NASA, Human Needs: Sustaining Life During [35] G.B. Sanders, In-Situ resource utilization Exploration, 2007, (ISRU) capability roadmap, NASA/JSC, 19 May https://www.nasa.gov/vision/earth/everydaylife/jame 2005 stown-needs-fs.html, (accessed 17.08.19) [36] K.L. Kramer, Sustainability, User Experience [24] L. Taylor, H. Schmitt, W. David Carrier III, M. and Design, Science Direct (2012) Nakagawa, The Lunar Dust Problem: From Liability [37] International Space University, Sustainable to Asset, American Institute of Aeronautics and Moon, Team Project (2019) Astronautics, [38] M. Sheetz, The space industry will be worth https://pdfs.semanticscholar.org/245b/0dff96d360d32 nearly $3 trillion in 30 years, Bank of America dd09d6f3541b1723e199560.pdf, (accessed 29.09.19) predicts, CNBC, 2017, [25] M. Hyatt, J. Feighery, Lunar Dust: https://www.cnbc.com/2017/10/31/the-space- Characterization and Mitigation, National industry-will-be-worth-nearly-3-trillion-in-30-years- Aeronautics and Space Administration, 9th ICEUM bank-of-america-predicts.html, (accessed 15.08.19) Sorrento, Italy, 24 October 2007 [39] J.C. Mankins, SPS- Alpha: The first practical [26] A. Campbell, Optical Communication solar power satellite via arbitrarily large phased Demonstration, 7 November 2017, array, NASA innovative Advanced Concepts https://www.nasa.gov/directorates/heo/scan/engineeri Program, 15 September 2012 ng/technology/txt_opticalcomm_start.html, (accessed [40] D. Kornuta, A.A. Madrid, J. Atkinson, (et al), 29.09.19) Commercial Lunar Propellant Architecture: A [27] Forbes, How did Neil Armstrong communicate Collaborative Study of Lunar Propellant Production, with Earth from the surface of the Moon, 20 February REACH, Vol. 13, 100026 (2019) 2019, [41] C.B. Dreyer, G. Sowers, H. Williams, Ice https://www.forbes.com/sites/quora/2018/02/20/how- Mining in Lunar Permanently Shadowed Regions, 9th did-neil-armstrong-communicate-with-earth-from- Joint Meeting of the Space Resources Roundtable the-surface-of-the-moon/#6745e3f65979, (accessed and Planetary and Terrestrial Mining Sciences 05.07.19) Symposium, Golden, CO, 2018 [28] L. Jenner, NASA eyes GPS at the Moon for [42] G. Sowers, Closing the business case of lunar Artemis missions, 28 June 2019, propellant, Center of Space Resources, Colorado https://www.nasa.gov/feature/goddard/2019/nasa- School of Mines, 12 June 2018, eyes-gps-at-the-moon-for-artemis-missions, (accessed 29.09.19) [29] EPA, NAAQS Table, https://www.epa.gov/criteria-air-pollutants/naaqs- table, (accessed 29.09.19) [30] L. Leveton, A. Whitmire, H. Broughton, (et al), Minimum Acceptable Net Habitable Volume for Long-Duration Exploration Missions Subject Matter Expert Consensus Session Report, NASA JSC-CN- 32284, 01 January 2014 [31] Bigelow Aerospace, Meet “First Base” A lunar landers best friend. (accessed 24 Sep 2019) http://bigelowaerospace.com/pages/firstbase/ [32] R.K. Tripathi, J.W. Wilson, R.C. Youngquist, Electrostatic space radiation shielding, Advances in

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