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Abstract: What is it about the Moon that captures the fancy of humankind? A silvery disk hanging in the night sky, it conjures up images of romance and magic. It has been counted upon to foreshadow important events, both of good and ill, and its phases for eons served humanity as its most accurate measure of time. This paper discusses the Moon as a target for human exploration and eventual settlement. This paper will explore the more than 50-year efforts to reach the Moon, succeeding with space probes and humans in Project Apollo in the 1960s and early 1970s. It will then discuss the rationales for spaceflight, suggesting that human space exploration is one of the least compelling of all that might be offered. The paper will then discuss efforts to make the Moon a second home, including post-Apollo planning, the Space Exploration Initiative, and problems and opportunities in the 2004 Vision for Space Exploration, and cancellation of that program in 2010. [Copyright &y& Elsevier]

NASA planning for the human space flight frontier is coming into alignment with the goals of other planetary-capable national space agencies and independent commercial actors. US Space Policy Directive 1 made this shift explicit: "the United States will lead the return of humans to the Moon for long-term exploration and utilization". The stage is now set for public and private American investment in a wide range of lunar activities. Assumptions about Moon base architectures and operations are likely to drive the invention of requirements that will in turn govern development of systems, commercial-services purchase agreements, and priorities for technology investment. Yet some fundamental architecture-shaping lessons already captured in the literature are not clearly being used as drivers, and remain absent from typical treatments of lunar base concepts. A prime example is general failure to recognize that most of the time (i.e., before and between intermittent human occupancy), a Moon base must be robotic: most of the activity, most of the time, must be implemented by robot agents rather than astronauts. This paper reviews key findings of a seminal robotic-base design-operations analysis commissioned by NASA in 1989. It discusses implications of these lessons for today's Moon Village and SPD-1 paradigms: exploration by multiple actors; public-private partnership development and operations; cislunar infrastructure; production-quantity exploitation of volatile resources near the poles to bootstrap further space activities; autonomy capability that was frontier in 1989 but now routine within terrestrial industry. It outlines new work underway to close these gaps; and articulates conclusions that can guide future work. • Most of the time, most of a Moon base is robotic. • Base elements designed for robotic operations challenge conventional concepts. • Hierarchical supervisory control is essential. Full autonomy is not. • All known base functions can be emplaced completely robotically. • A habitable, oxygen-producing base can be constructed in less than four years of quarterly flights. [ABSTRACT FROM AUTHOR]

Abstract: The current emphasis in the US and internationally on lunar robotic missions is generally viewed as a precursor to possible future human missions to the Moon. As initially framed, the implementation of high level policies such as the US Vision for Space Exploration (VSE) might have been limited to either human lunar sortie missions, or to the testing at the Moon of concepts-of-operations and systems for eventual human missions to Mars [White House, Vision for Space Exploration, Washington, DC, 14 January, 2004. ]. However, recently announced (December 2006) US goals go much further: these plans now place at the center of future US—and perhaps international—human spaceflight activities a long-term commitment to an outpost on the Moon. Based on available documents, a human lunar outpost could be emplaced as early as the 2020–2025 timeframe, and would involve numerous novel systems, new technologies and unique operations requirements. As such, substantial investments in research and development (R&D) will be necessary prior to, during, and following the deployment of such an outpost. It seems possible that such an outpost will be an international endeavor, not just the undertaking of a single country—and the US has actively courted partners in the VSE. However, critical questions remain concerning an international lunar outpost. What might such an outpost accomplish? To what extent will “sustainability” be built into the outpost? And, most importantly, what will be the outpost''s life cycle cost (LCC)? This paper will explore these issues with a view toward informing key policy and program decisions that must be made during the next several years. The paper will (1) describe a high-level analytical model of a modest lunar outpost, (2) examine (using this model) the parametric characteristics of the outpost in terms of the three critical questions indicated above, and (3) present rough estimates of the relationships of outpost goals and “sustainability” to LCC. The paper will also consider possible outpost requirements for near-term investments in enabling research in light of experiences in past advanced technology programs. [Copyright &y& Elsevier]

Abstract: An energy efficiency and control analysis is given for application of a transparent electric curtain for dust mitigation on a solar panel. The electric curtain technique has been proposed by NASA as an effective active method for dust removal from solar panels in planetary and lunar exploration, and this method also has potential for mitigation of dust build-up on terrestrial solar panels in dry environments. Since energy expenditure rate required for electric curtain operation can be significantly higher than the energy capture rate from a solar panel, a control scheme for activation and deactivation of the electric curtain is necessary to achieve optimal net energy capture. The control method examined in the current paper is one in which the electric curtain is activated when the panel output voltage decreases to a fraction of the clean panel output voltage and deactived when the output voltage exceeds a second output voltage fraction . A combination of theoretical and computational approaches is used to determine how the energy efficiency changes with change in the threshold voltage ratios. A scaling analysis is developed that identifies a single key dimensionless parameter that influences the efficiency results. Optimal values of turn-on and turn-off voltage ratio are determined in terms of this parameter, and it is demonstrated that the efficiency decreases rapidly as the turn-off voltage ratio is raised above the optimal value. All of the efficiency predictions for a given mitigation velocity profile are collapsed onto a single curve with appropriate choice of the scaling parameters, which is then used to develop an optimal control criterion. [Copyright &y& Elsevier]

Abstract: Mars is covered with a layer of dust that has been homogenized by global dust storms. Dust, levitated by these storms as well as by the frequent dust devils, is the dominant weather phenomenon on Mars. NASA''s Mars exploration rovers have shown that atmospheric dust falling on solar panels can decrease their efficiency to the point of rendering the rover unusable. Dust covering the surface of the moon is expected to be electrostatically charged due to the solar wind, cosmic rays, and the solar radiation itself through the photoelectric effect. Electrostatically charged dust has a large tendency to adhere to surfaces. The Apollo missions to the moon showed that lunar dust adhesion can hinder manned and unmanned exploration activities. In this paper, we report on our efforts to develop an electrodynamic dust shield to prevent the accumulation of dust on surfaces and to remove dust already adhering to those surfaces. The technology uses electrostatic and dielectrophoretic forces to carry dust particles off surfaces and to generate an electrodynamic shield that prevents further accumulation of dust. The concept of the electrodynamic dust shield was introduced by NASA in the late 1960s and later reduced to practice during the 1970s for terrestrial applications. In 2003, our laboratory, in collaboration with several universities, applied this technology to space applications, specifically to remove dust from solar panels on Mars. We show how, with an appropriate design, we can prevent the electrostatic breakdown at the low Martian atmospheric pressures. We are also able to show that uncharged dust can be lifted and removed from surfaces under simulated Martian environmental conditions. We have also been able to develop a version of the electrodynamic dust shield working under hard vacuum conditions that simulate the lunar environment. We have implemented the electrodynamic dust shield on solar arrays, optical systems, spectrometers, viewports, thermal radiators, batteries, and power systems, as well as on fabrics for spacesuits. We present data on the design and optimization of the electrodynamic dust shields and provide data on the performance of the different implementations of the technology for lunar and Martian exploration activities. [Copyright &y& Elsevier]

Abstract: There has been increased interest in the exploration of the Moon in recent years. Pin-point precision landing is highly desirable for future lunar missions. This paper is concerned with the design of the on-board data handling (OBDH) subsystem for the pin-point lunar lander of the Magnolia-1 project, funded by NASA. Four proposed on-board data handling architectures are outlined and compared in terms of power consumption, performance and reliability. Implementation results are presented, which are obtained from prototyping of the flight computer for the optimal OBDH architecture option on a Xilinx Virtex-5 Field Programmable Gate Array. [Copyright &y& Elsevier]

Abstract: Robotic reconnaissance (“recon”) has the potential to significantly improve scientific and technical return from lunar surface exploration. In particular, robotic recon can be used to improve traverse planning, reduce operational risk, and increase crew productivity. To study how robotic recon can benefit human exploration, we recently conducted a field experiment at Black Point Lava Flow (BPLF), Arizona. In our experiment, a simulated ground control team at NASA Ames teleoperated a planetary rover to scout geology traverses at BPLF. The recon data were then used to plan revised traverses. Two-man crews subsequently performed both types of traverses using the NASA “Lunar Electric Rover” (LER) and simulated extra-vehicular activity (EVA) suits. This paper describes the design of our experiment, presents our results, and discusses directions for future research. [ABSTRACT FROM AUTHOR]

Abstract: As the NASA Vision for Space Exploration takes shape, one of the key issues that will affect the lunar exploration is the ability to provide electric power to various surface locations. This power should be available through daylight times as well as night times. While nuclear reactors and radioisotope power sources are a choice for continuous power, it is the purpose of this paper to explore the advantages of an electric propulsion spacecraft plus laser power beaming to provide power to any location on the lunar surface. The starting point for the electric propulsion mission is a 500km altitude. Thrusting only occurs when the satellite is in sunlight. Radiation damage that occurs during transit of the Earth''s radiation belts is taken into account. The satellite is placed in a 30,000 by 500km orbit around the moon where it beams power to locations within 45° north or south of the equator. Laser power beaming only occurs when the satellite views the sun and the surface location is in the dark. Power delivered to the surface over a two year mission is presented along with the results of adding a second satellite. With two satellites, the maximum time when the site won’t receive power at night is about three days. This significantly reduces the need for a lunar storage system. [Copyright &y& Elsevier]

Abstract: On 14 January 2004 President George Bush announced his vision for space exploration, to include a human return to the Moon. He argued that, with a moderate increase in NASA''s annual expenditure, such a return was possible. This paper is an exploration of how the President''s space initiative can be realised on an international co-operative basis along similar lines to those already existing with the international space station (ISS). By abandoning the concept of a lunar landing as the major goal of a lunar programme, the initiative is made feasible. The three-stage plan here presented meshes with the currently evolving plans for the US space initiative to provide a realistic, affordable and sustainable strategy for manned lunar exploration. It represents a significant opportunity for the USA to unite and lead the world on this grand, civilisation defining adventure. [Copyright &y& Elsevier]

Abstract: As part of the refocusing of NASA from Space Station research to exploration research, we are pursuing a number of proposed and funded projects for lunar exploration using cryogenic techniques. This paper gives a summary of these projects which include: (1) Using passive radiative cooling for separation and storage of volatiles from lunar regolith; (2) Studies of boiling and two-phase flow under lunar gravity; (3) SQUID-based MRI for monitoring astronaut health; (4) Studies of volatiles and water ice in permanently shadowed craters at the lunar poles; and (5) Seismic search for strange quark matter using the Moon as a large and seismically quiet detector. [Copyright &y& Elsevier]

Abstract: In announcing a new Vision for the US space program, President George Bush committed the USA to “a long-term human and robotic program to explore the solar system”, via a return to the Moon, leading to exploration of Mars and other destinations. He also stated that other nations would be invited to join the vision. Many other nations have, or are developing, ‘exploration visions’ of their own. The potential for international cooperation therefore exists, both at the vision and program/project levels. This paper, based on Working Group discussions as part of an AIAA space cooperation workshop, 1 [1] The workshop was held in Anchorage, Alaska, 2–6 May 2004 and the Working Group discussed ‘International Cooperation in the Context of the Implementation of a Space Exploration Vision’. It took as its mandate the following statement: “In announcing his new Vision for space exploration, President Bush stated that ‘We‘ll invite other nations to share the challenge and the opportunities of this new era of discovery.’ Having characterized the Vision as ‘a journey, not a race’ he then called ‘on other nations to join us on this journey, in a spirit of cooperation and friendship.’ Other nations also have specific exploration missions or comprehensive exploration agendas (e.g. ESA''s Aurora program) as an integral part of their overall space strategies. Based on this background, the Working Group provided an appropriate independent forum in which to discuss the modalities of defining and implementing an exploration vision as a coordinated international endeavor.” The full report of the Workshop (Report of the AIAA 7th workshop on international space cooperation, working group on “International Cooperation in the Context of a Space Exploration Vision”, May 3–6, 2004), containing details of the output of this Working Group and two others addressing different topics, can be found on the AIAA''s web site at www.aiaa.org, under ‘International Outreach’. presents an approach for maximizing the return on all global investments in space exploration. It proposes an international coordination mechanism through which all these various national activities could be integrated into an inherently global enterprise for space exploration, a ‘virtual program of programs’. Within the context of the coordination, individual activities would utilize the full range of cooperative mechanisms for implementation. A significant benefit of this mode of conducting cooperation is that it would not require the negotiation of complex overarching international agreements as a precondition for initiating international activity. [Copyright &y& Elsevier]