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NASA NTRS2008

2003 Mars Exploration Rover Mission: Robotic Field Geologists for a Mars Sample Return Mission

The Mars Exploration Rover (MER) Spirit landed in Gusev crater on Jan. 4, 2004 and the rover Opportunity arrived on the plains of Meridiani Planum on Jan. 25, 2004. The rovers continue to return new discoveries after 4 continuous Earth years of operations on the surface of the red planet. Spirit has successfully traversed 7.5 km over the Gusev crater plains, ascended to the top of Husband Hill, and entered into the Inner Basin of the Columbia Hills. Opportunity has traveled nearly 12 km over flat plains of Meridiani and descended into several impact craters. Spirit and Opportunity carry an integrated suite of scientific instruments and tools called the Athena science payload. The Athena science payload consists of the 1) Panoramic Camera (Pancam) that provides high-resolution, color stereo imaging, 2) Miniature Thermal Emission Spectrometer (Mini-TES) that provides spectral cubes at mid-infrared wavelengths, 3) Microscopic Imager (MI) for close-up imaging, 4) Alpha Particle X-Ray Spectrometer (APXS) for elemental chemistry, 5) Moessbauer Spectrometer (MB) for the mineralogy of Fe-bearing materials, 6) Rock Abrasion Tool (RAT) for removing dusty and weathered surfaces and exposing fresh rock underneath, and 7) Magnetic Properties Experiment that allow the instruments to study the composition of magnetic martian materials [1]. The primary objective of the Athena science investigation is to explore two sites on the martian surface where water may once have been present, and to assess past environmental conditions at those sites and their suitability for life. The Athena science instruments have made numerous scientific discoveries over the 4 plus years of operations. The objectives of this paper are to 1) describe the major scientific discoveries of the MER robotic field geologists and 2) briefly summarize what major outstanding questions were not answered by MER that might be addressed by returning samples to our laboratories on Earth.

Ming, Douglas W.↗

DOE OSTI2015

Constraints on the richness–mass relation and the optical-SZE positional offset distribution for SZE-selected clusters

Abstract Not Provided

Astrophysics,ASTRO↗

NASA NTRS1971

Lessons learned from a decade of international space cooperation.

A case history of the Alouette/ISIS series is presented, giving attention to aspects of U.S.-Canadian cooperation in this program. The project is only one example of a broad network of international cooperative relationships established by NASA over the past decade. Participation by other countries in important space science and applications projects is not limited to those providing flight hardware or conducting flight observations. Much valuable work is done on the ground, ranging from analysis in the laboratories of samples returned from the moon to correlated ground-based reception and analysis of radio beacon signals from satellites. It was found that cooperation is more likely to proceed smoothly and produce beneficial results if it is focused on projects that are clearly defined and agreed on in advance.

Barnes, R. J. H.↗

NASA NTRS1992

MRSR: Rationale for a Mars Rover/Sample Return mission

The Solar System Exploration Committee of the NASA Advisory Council has recommended that a Mars Rover/Sample Return mission be launched before the year 2000. The recommendation is consistent with the science objectives as outlined by the National Academy of Sciences committees on Planetary and Lunar Exploration, and Planetary Biology and Chemical Evolution. Interest has also focused on Mars Rover/Sample Return (MRSR) missions, because of their crucial role as precursors for human exploration. As a result of this consensus among the advisory groups, a study of an MRSR mission began early in 1987. The study has the following goals: (1) to assess the technical feasibility of the mission; (2) to converge on two or three options for the general architecture of the mission; (3) to determine what new technologies need to be developed in order to implement the mission; (4) to define the different options sufficiently well that preliminary cost estimates can be made; and (5) to better define the science requirements. This chapter briefly describes Mars Rover/Sample Return missions that were examined in the late 1980s. These missions generally include a large (1000 kg) rover and return of over 5 kg of sample.

Carr, Michael H.↗

NASA NTRS2001

Exploration of Titan Using Vertical Lift Aerial Vehicles

Autonomous vertical lift aerial vehicles (such as rotorcraft or powered-lift vehicles) hold considerable potential for supporting planetary science and exploration missions. Vertical lift aerial vehicles would have the following advantages/attributes for planetary exploration: (1) low-speed and low-altitude detailed aerial surveys; (2) remote-site sample return to lander platforms; (3) precision placement of scientific probes; (4) soft landing capability for vehicle reuse (multiple flights) and remote-site monitoring; (5) greater range, speed, and access to hazardous terrain than a surface rover; and (6) greater resolution of surface details than an orbiter or balloons. Exploration of Titan presents an excellent opportunity for the development and usage of such vehicles. Additional information is contained in the original extended abstract.

Young, L. A.↗

NASA NTRS2001

Searching for life in the universe: lessons from the earth

Space programs will soon allow us to search for life in situ on Mars and to return samples for analysis. A major focal point is to search for evidence of present or past life in these samples, evidence that, if found, would have far-reaching consequences for both science and religion. A search strategy will consider the entire gamut of life on our own planet, using that information to frame a search that would recognize life even if it were fundamentally different from that we know on Earth. We discuss here how the lessons learned from the study of life on Earth can be used to allow us to develop a general strategy for the search for life in the Universe.

Extraterrestrial Environment↗

NASA NTRS2012

NASA In-Space Propulsion Technologies and Their Infusion Potential

The In-Space Propulsion Technology (ISPT) program has been developing in-space propulsion technologies that will enable or enhance NASA robotic science missions. The ISPT program is currently developing technology in four areas that include Propulsion System Technologies (Electric and Chemical), Entry Vehicle Technologies (Aerocapture and Earth entry vehicles), Spacecraft Bus and Sample Return Propulsion Technologies (components and ascent vehicles), and Systems/Mission Analysis. Three technologies are ready for flight infusion: 1) the high-temperature Advanced Material Bipropellant Rocket (AMBR) engine providing higher performance; 2) NASA s Evolutionary Xenon Thruster (NEXT) ion propulsion system, a 0.6-7 kW throttle-able gridded ion system; and 3) Aerocapture technology development with investments in a family of thermal protection system (TPS) materials and structures; guidance, navigation, and control (GN&C) models of blunt-body rigid aeroshells; and aerothermal effect models. Two component technologies that will be ready for flight infusion in the near future will be Advanced Xenon Flow Control System, and ultra-lightweight propellant tank technologies. Future focuses for ISPT are sample return missions and other spacecraft bus technologies like: 1) Mars Ascent Vehicles (MAV); 2) multi-mission technologies for Earth Entry Vehicles (MMEEV) for sample return missions; and 3) electric propulsion for sample return and low cost missions. These technologies are more vehicle-focused, and present a different set of technology infusion challenges. While the Systems/Mission Analysis area is focused on developing tools and assessing the application of propulsion technologies to a wide variety of mission concepts. These in-space propulsion technologies are applicable, and potentially enabling for future NASA Discovery, New Frontiers, and sample return missions currently under consideration, as well as having broad applicability to potential Flagship missions. This paper provides a brief overview of the ISPT program, describing the development status and technology infusion readiness of in-space propulsion technologies in the areas of electric propulsion, aerocapture, Earth entry vehicles, propulsion components, Mars ascent vehicle, and mission/systems analysis.

Anderson, David↗

NASA NTRS2012

NASA In-Space Propulsion Technologies and Their Infusion Potential

Anderson, David J.↗

NASA NTRS2013

The Status of Spacecraft Bus and Platform Technology Development under the NASA ISPT Program

The In-Space Propulsion Technology (ISPT) program is developing spacecraft bus and platform technologies that will enable or enhance NASA robotic science missions. The ISPT program is currently developing technology in four areas that include Propulsion System Technologies (electric and chemical), Entry Vehicle Technologies (aerocapture and Earth entry vehicles), Spacecraft Bus and Sample Return Propulsion Technologies (components and ascent vehicles), and Systems/Mission Analysis. Three technologies are ready for near-term flight infusion: 1) the high-temperature Advanced Material Bipropellant Rocket (AMBR) engine providing higher performance; 2) NASA s Evolutionary Xenon Thruster (NEXT) ion propulsion system, a 0.6-7 kW throttle-able gridded ion system; and 3) Aerocapture technology development with investments in a family of thermal protection system (TPS) materials and structures; guidance, navigation, and control (GN&C) models of blunt-body rigid aeroshells; and aerothermal effect models. Two component technologies being developed with flight infusion in mind are the Advanced Xenon Flow Control System and ultralightweight propellant tank technologies. Future directions for ISPT are technologies that relate to sample return missions and other spacecraft bus technology needs like: 1) Mars Ascent Vehicles (MAV); 2) multi-mission technologies for Earth Entry Vehicles (MMEEV); and 3) electric propulsion. These technologies are more vehicles and mission-focused, and present a different set of technology development and infusion steps beyond those previously implemented. The Systems/Mission Analysis area is focused on developing tools and assessing the application of propulsion and spacecraft bus technologies to a wide variety of mission concepts. These inspace propulsion technologies are applicable, and potentially enabling for future NASA Discovery, New Frontiers, and sample return missions currently under consideration, as well as having broad applicability to potential Flagship missions. This paper provides a brief overview of the ISPT program, describing the development status and technology infusion readiness of in-space propulsion technologies in the areas of electric propulsion, Aerocapture, Earth entry vehicles, propulsion components, Mars ascent vehicle, and mission/systems analysis.

Anderson, David J.↗

NASA NTRS2013

The Status of Spacecraft Bus and Platform Technology Development Under the NASA ISPT Program

The In-Space Propulsion Technology (ISPT) program is developing spacecraft bus and platform technologies that will enable or enhance NASA robotic science missions. The ISPT program is currently developing technology in four areas that include Propulsion System Technologies (electric and chemical), Entry Vehicle Technologies (aerocapture and Earth entry vehicles), Spacecraft Bus and Sample Return Propulsion Technologies (components and ascent vehicles), and Systems/Mission Analysis. Three technologies are ready for near-term flight infusion: 1) the high-temperature Advanced Material Bipropellant Rocket (AMBR) engine providing higher performance 2) NASAs Evolutionary Xenon Thruster (NEXT) ion propulsion system, a 0.6-7 kW throttle-able gridded ion system and 3) Aerocapture technology development with investments in a family of thermal protection system (TPS) materials and structures guidance, navigation, and control (GN&C) models of blunt-body rigid aeroshells and aerothermal effect models. Two component technologies being developed with flight infusion in mind are the Advanced Xenon Flow Control System, and ultra-lightweight propellant tank technologies. Future direction for ISPT are technologies that relate to sample return missions and other spacecraft bus technology needs like: 1) Mars Ascent Vehicles (MAV) 2) multi-mission technologies for Earth Entry Vehicles (MMEEV) and 3) electric propulsion. These technologies are more vehicle and mission-focused, and present a different set of technology development and infusion steps beyond those previously implemented. The Systems/Mission Analysis area is focused on developing tools and assessing the application of propulsion and spacecraft bus technologies to a wide variety of mission concepts. These in-space propulsion technologies are applicable, and potentially enabling for future NASA Discovery, New Frontiers, and sample return missions currently under consideration, as well as having broad applicability to potential Flagship missions. This paper provides a brief overview of the ISPT program, describing the development status and technology infusion readiness of in-space propulsion technologies in the areas of electric propulsion, Aerocapture, Earth entry vehicles, propulsion components, Mars ascent vehicle, and mission/systems analysis.

Anderson, David J.↗

NASA NTRS2013

Remote Observations of Reentering Spacecraft Including the Space Shuttle Orbiter

Flight measurement is a critical phase in development, validation and certification processes of technologies destined for future civilian and military operational capabilities. This paper focuses on several recent NASA-sponsored remote observations that have provided unique engineering and scientific insights of reentry vehicle flight phenomenology and performance that could not necessarily be obtained with more traditional instrumentation methods such as onboard discrete surface sensors. The missions highlighted include multiple spatially-resolved infrared observations of the NASA Space Shuttle Orbiter during hypersonic reentry from 2009 to 2011, and emission spectroscopy of comparatively small-sized sample return capsules returning from exploration missions. Emphasis has been placed upon identifying the challenges associated with these remote sensing missions with focus on end-to-end aspects that include the initial science objective, selection of the appropriate imaging platform and instrumentation suite, target flight path analysis and acquisition strategy, pre-mission simulations to optimize sensor configuration, logistics and communications during the actual observation. Explored are collaborative opportunities and technology investments required to develop a next-generation quantitative imaging system (i.e., an intelligent sensor and platform) with greater capability, which could more affordably support cross cutting civilian and military flight test needs.

Horvath, Thomas J.↗

NASA NTRS2013

Spacecraft Bus and Platform Technology Development under the NASA ISPT Program

The In-Space Propulsion Technology (ISPT) program is developing spacecraft bus and platform technologies that will enable or enhance NASA robotic science missions. The ISPT program is currently developing technology in four areas that include Propulsion System Technologies (electric and chemical), Entry Vehicle Technologies (aerocapture and Earth entry vehicles), Spacecraft Bus and Sample Return Propulsion Technologies (components and ascent vehicles), and Systems/Mission Analysis. Three technologies are ready for near-term flight infusion: 1) the high-temperature Advanced Material Bipropellant Rocket (AMBR) engine providing higher performance; 2) NASA s Evolutionary Xenon Thruster (NEXT) ion propulsion system, a 0.6-7 kW throttle-able gridded ion system; and 3) Aerocapture technology development with investments in a family of thermal protection system (TPS) materials and structures; guidance, navigation, and control (GN&C) models of blunt-body rigid aeroshells; and aerothermal effect models. Two component technologies being developed with flight infusion in mind are the Advanced Xenon Flow Control System, and ultra-lightweight propellant tank technologies. Future direction for ISPT are technologies that relate to sample return missions and other spacecraft bus technology needs like: 1) Mars Ascent Vehicles (MAV); 2) multi-mission technologies for Earth Entry Vehicles (MMEEV) for sample return missions; and 3) electric propulsion for sample return and low cost missions. These technologies are more vehicle and mission-focused, and present a different set of technology development and infusion steps beyond those previously implemented. The Systems/Mission Analysis area is focused on developing tools and assessing the application of propulsion and spacecraft bus technologies to a wide variety of mission concepts. These in-space propulsion technologies are applicable, and potentially enabling for future NASA Discovery, New Frontiers, and sample return missions currently under consideration, as well as having broad applicability to potential Flagship missions. This paper provides a brief overview of the ISPT program, describing the development status and technology infusion readiness of in-space propulsion technologies in the areas of electric propulsion, Aerocapture, Earth entry vehicles, propulsion components, Mars ascent vehicle, and mission/systems analysis.

Anderson, David J.↗

NASA NTRS2013

Spacecraft Bus and Platform Technology Development under the NASA ISPT Program

The In-Space Propulsion Technology (ISPT) program is developing spacecraft bus and platform technologies that will enable or enhance NASA robotic science missions. The ISPT program is currently developing technology in four areas that include Propulsion System Technologies (electric and chemical), Entry Vehicle Technologies (aerocapture and Earth entry vehicles), Spacecraft Bus and Sample Return Propulsion Technologies (components and ascent vehicles), and Systems/Mission Analysis. Three technologies are ready for near-term flight infusion: 1) the high-temperature Advanced Material Bipropellant Rocket (AMBR) engine providing higher performance 2) NASAs Evolutionary Xenon Thruster (NEXT) ion propulsion system, a 0.6-7 kW throttle-able gridded ion system and 3) Aerocapture technology development with investments in a family of thermal protection system (TPS) materials and structures guidance, navigation, and control (GN&C) models of blunt-body rigid aeroshells and aerothermal effect models. Two component technologies being developed with flight infusion in mind are the Advanced Xenon Flow Control System, and ultra-lightweight propellant tank technologies. Future direction for ISPT are technologies that relate to sample return missions and other spacecraft bus technology needs like: 1) Mars Ascent Vehicles (MAV) 2) multi-mission technologies for Earth Entry Vehicles (MMEEV) for sample return missions and 3) electric propulsion for sample return and low cost missions. These technologies are more vehicle and mission-focused, and present a different set of technology development and infusion steps beyond those previously implemented. The Systems/Mission Analysis area is focused on developing tools and assessing the application of propulsion and spacecraft bus technologies to a wide variety of mission concepts. These in-space propulsion technologies are applicable, and potentially enabling for future NASA Discovery, New Frontiers, and sample return missions currently under consideration, as well as having broad applicability to potential Flagship missions. This paper provides a brief overview of the ISPT program, describing the development status and technology infusion readiness of in-space propulsion technologies in the areas of electric propulsion, Aerocapture, Earth entry vehicles, propulsion components, Mars ascent vehicle, and mission/systems analysis.

Anderson, David J.↗

NASA NTRS2012

The DECLIC Research Facility - a Fertile Platform for NASA/CNES Scientific Collaboration

The DECLIC (Device for the Study of Critical Liquids and Crystalization) Facility was launched to the International Space Station (ISS) on Shuttle flight 17-A (August 2009) and has been in service for a little over three years. Activity from the three originally planned investigations, the HTI (High Temperature Insert) investigation, the ALI (Alice Like Insert) investigation and the DSI (Directional Solidication Insert) investigation has led to fruitful collaborations among a team of scientists, sponsored by NASA and CNES, to extend the utility of the inserts and the breadth of science beyond its initial scope. These follow-on investigations plan to use inserts that have been returned to earth for refurbishment, two of which (i.e., HTI-R and DSI-R) simply entail changing the test sample and the third (i.e., ALI-R) entails a slight hardware modication to allow for precise changes in sample volume. The first investigation, the Supercritical Water Mixture (SCWM) experiment, uses the refurbished HTI-R, which will accommodate a dilute aqueous mixture of Na2SO4 -0.5% w. This investigation will extend earlier observations of pure water at near-critical conditions. The second experiment uses a modified insert, the DSI-R, with a different concentration of succinonitrile-camphor than the original flight sample. This will allow, among other objectives, a detailed study of dendritic sidebranch formation in extended three-dimensional arrays, with the goal of elucidating whether noise amplication and/or a deterministic limit cycle is the main cause of sidebranch formation. The final experiment, the ALI-R, uses a sample cell with variable density to allow for additional observations of thermo-physical properties on SF6 at near critical conditions. The presentation will provide a discussion of the DECLIC facility's hardware, its modied inserts, and an overview of the extended science that will be achieved through these collaborative activities.

Hicks, Michael C.↗

NASA NTRS2017

Sample Curation in Support of the OSIRIS-REx Asteroid Sample Return Mission

The OSIRIS-REx asteroid sample return mission launched to asteroid Bennu Sept. 8, 2016. The spacecraft will arrive at Bennu in late 2019, orbit and map the asteroid, and perform a touch and go (TAG) sampling maneuver in July 2020. After sample is stowed and confirmed the spacecraft will return to Earth, and the sample return capsule (SRC) will land in Utah in September 2023. Samples will be recovered from Utah [2] and then transported and stored in a new sample cleanroom at NASA Johnson Space Center in Houston [3]. The materials curated for the mission are described here. a) Materials Archive and Witness Plate Collection: The SRC and TAGSAM were built between March 2014 and Summer of 2015, and instruments (OTES,OVIRS, OLA, OCAMS, REXIS) were integrated from Summer 2015 until May 2016. A total of 395 items were received for the materials archive at NASA-JSC, with archiving finishing ~30 days after launch (with the final archived items being related to launch operations)[4]. The materials fall into several general categories including metals (stainless steel, aluminum, titanium alloys, brass and BeCu alloy), epoxies, paints, polymers, lubricants, non-volatile-residue samples (NVR), sapphire, and various miscellaneous materials. All through the ATLO process (from March 2015 until late August 2016) contamination knowledge witness plates (Si wafer and Al foil) were deployed in the various cleanrooms in Denver and KSC to provide an additional record of particle counts and volatiles that is archived for current and future scientific studies. These plates were deployed in roughly monthly increments with each unit containing 4 Si wafers and 4 Al foils. We archived 128 individual witness plates (64 Si wafers and 64 Al foils); one of each witness plate (Si and Al) was analyzed immediately by the science team after archiving, while the remaining 3 of each are archived indefinitely. Information about each material archived is stored in an extensive database at NASA-JSC, and key summary information for each will be presented in an online catalog. b) Bulk Asteroid sample: The Touch and Go Sampling Mechanism (TAGSAM) head will contain up to 1.5 kg of asteroid material. Upon return to Earth, the TAGSAM head with the sample canister will be subjected to a nitrogen purge and then opened in a nitrogen cabinet in Houston. Once the TAGSAM head is removed from the canister, it will be dis-assembled slowly and carefully under nitrogen until the sample can be removed for processing in a dedicated nitrogen glovebox. Bennu surface samples are expected to be sub-cm sized, based on thermal infrared and radar polarization ratio measurements [1]. The upper limit on material collected by the TAGSAM head is ~2 cm. Therefore, we will be prepared to handle, subdivide, and characterize materials of a wide grain size (from ~10 m to 2 cm), and for both organic (UV fluorescence) and inorganic (SEM, FTIR, optical) properties. Representative portions of the bulk sample will be prepared for JAXA (0.5 %; see also [5]) and Canadian Space Agency (4%), with the remaining divided between the science team (<25%) and archived for future studies (NASA) (>75%). c) Contact Pad samples: The base of the TAGSAM head contains 24 contact pads that are designed to trap the upper surface layer of material and thus offer an opportunity to study asteroid samples that have resided at the very top surface of the regolith. Asteroid material is trapped on the pads in spring steel Velcro hooks, and material will have to be removed from these pads by curation specialists in the lab. d) Hardware: Some canister and SRC hardware items will contain information that will be important to understanding the collected samples, including the canister gas filter, temperature strips, flight witness plates, and the TAGSAM and canister parts that might have adhering dust grains. Some challenges remaining for both bulk sample and contact pad samples include: i) working with intermediate size range (200 to 500 micron) samples - a size range NASA has not previously worked in such detail; ii) techniques for removal of contact pad material from the spring steel hooks, iii) static electrical effects of dust sized particles during sample handling and curation is likely to be significant, and iv) the TAGSAM head and associated canister hardware will undoubtedly be coated with fine adhering dust grains from Bennu. In the case of collection of a large bulk sample mass, the adhering dust grains may be of lower priority. If a small sample mass is returned, the adhering dust may attain a higher priority, so recovery of adhering dust grains is an additional challenge to consider. In the year leading up to sample return we plan a variety of sample handling rehearsals that will enables the curation team to be prepared for many new aspects posed by this sample suite.

Righter, Kevin↗

DOE OSTI2020

Comparative Analysis of Thrombin Calibration Algorithms and Correction for Thrombin-α2macroglobulin Activity

Background: The thrombin generation (TG) test is useful for characterizing global hemostasis potential, but fluorescence substrate artifacts, such as thrombin-α2macroglobulin (T-α2MG) signal, inner filter effect (IFE), substrate consumption, and calibration algorithms have been suggested as sources of intra- and inter-laboratory variance, which may limit its clinical utility. Methods: Effects of internal vs. external normalization, IFE and T-α2MG on TG curves in normal plasma supplemented with coagulation factors, thrombomodulin, and tissue factor were studied using the Calibrated Automated Thrombinography (CAT; Diagnostica Stago, Parsippany, NJ, USA) and in-house software. Results: The various calibration methods demonstrated no significant difference in producing TG curves, nor increased the robustness of the TG assay. Several TG parameters, including thrombin peak height (TPH), produced from internal linear calibration did not differ significantly from uncalibrated TG parameters. Further, TPH values from internal linear and nonlinear calibration with or without T-α2MG correction correlated well with TPH from external calibration. Higher coefficients of variation (CVs) for TPH values were observed in both platelet-free and platelet-rich plasma with added thrombomodulin. Conclusions: Our work suggests minimal differences between distinct computational approaches toward calibrating and correcting fluorescence signals into TG levels, with most samples returning similar or equivalent TPH results.

59 BASIC BIOLOGICAL SCIENCES↗

NASA NTRS1981

Methods of participation in sortie mode science

The Shuttle offers an exciting new way to perform space experimentation, the 'sortie mode.' This mode allows experiments to be performed in the payload bay with subsequent return of the hardware, including data in the form of film, tapes, or samples, to the investigators. In pursuit of the objective of providing easy and routine access to space, a number of methods of participation in the sortie mode are being made available by NASA. These methods provide varying degrees of NASA funding, data rights, and flexibility. At one extreme is the 'Small, Self-Contained Payload' where a 60-pound payload can be flown on the Shuttle for a cost of $3,000. Alternately, one can propose an experiment in response to an 'Announcement of Opportunity' (AO) and receive substantial funding support for development and conduct of a major Spacelab experiment. These methods and others are discussed.

Pellerin, C. J., Jr.↗

NASA NTRS1999

In-Situ Production of Solar Power Systems for Exploration

Current proposals for developing an extended human presence, beyond space stations, on the Moon and Mars increasingly consider the processing of non-terrestrial materials essential for keeping the Earth launch burden reasonable. Utilization of in-situ resources for construction of lunar and Mars bases will initially require assessment of resource availability followed by the development of economically acceptable and technically feasible extractive processes. In regard to materials processing and fabrication the lower gravity level on the Moon (0.125 g) and Mars (0.367 g) will dramatically change the presently accepted hierarchy of materials in terms of specific properties, a factor which must be understood and exploited. Furthermore, significant changes are expected in the behavior of liquid materials during processing. In casting, for example, mold filling and associated solidification processes have to be reevaluated. Finally microstructural development and therefore material properties, presently being documented through on-going research in microgravity science and applications, needs to be understood and scaled to the reduced gravity environments. One of the most important elements of a human planetary base is power production. Lunar samples and geophysical measurements returned by the Apollo missions provide detailed data on the composition and physical characteristics of the lunar materials and environment. Based on this knowledge and extrapolations of terrestrial industrial experience it is clear that several types of solar-to-electric converters can be manufactured on the Moon. It is conceivable that well over 90% of a solar-to- electric power system could be made from lunar materials. Production and utilization of photovoltaic devices for solar energy production on Earth is primarily driven by the market economy. On Earth a production plant for photovoltaic devices is intimately linked to the planets massive industrial base. A selection of off the shelf refined materials are available as well as cheap fast transportation on demand. The processes takes place (except for the few seconds reprieve in shot towers etc.) under one gravity, with solar radiation significantly modulated by weather, and under conditions where one atmosphere is free and high vacuum is cumbersome and expensive. Off Earth, on lunar or Mars bases, the cost of photovoltaic power is driven by transport costs - Earth launch, deep space transport, landing on the planetary surface. Thus there is a premium for processes that are materials self-sufficient or for closed loop in-situ processes. The lack of differentiated ores on the Moon, and lack of explored minerals on Mars and interplanetary space give a premium to universal/non-ore-specific mineral extractive processes. Initially a semiconductor/photovoltaic production facility will build on no conveniently located industrial base, further increasing the premium on closed loop self sufficient processes.

Curreri, Peter A.↗