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Visible, near-infrared, and mid-infrared spectral characterization of Hawaiian fumarolic alteration near Kilauea's December 1974 flow: Implications for spectral discrimination of alteration environments on Mars
Motives, methods, and essential preparation for planetary field geology on the Moon and Mars
Future lunar exploration will provide opportunities to expand the human scientific exploration of the Moon and, eventually, Mars. Planning for renewed field exploration of the Moon entails the selection, training, and capabilities of explorers; selection of landing sites; and adoption of an operational approach to extravehicular activity. Apollo program geological exploration, and subsequent analysis and interpretation of findings and collected samples underpin our current understanding of lunar origin and history. That understanding continues to provide new and important insights into the early histories of Earth and other bodies in the solar system, particularly during the period when life formed and began to evolve on Earth and possibly on Mars. Specific new lunar exploration objectives include: (1) testing the consensus “giant impact” hypothesis for the origin of the Moon; (2) testing the consensus impact “cataclysm” hypothesis; (3) determining the temporal flux of large impacts in the inner solar system; and (4) investigating the internal structure of the Moon. Apollo samples also identified significant and potentially commercial lunar resources that could help satisfy future demand for both terrestrial energy alternatives and space consumables. Equipment necessary for successful exploration includes that required for sampling, sample documentation and preservation, communications, mobility, and position knowledge. Easily used active geophysical, portable geochemical, and in situ petrographic equipment can greatly enhance the scientific and operational returns of extended exploration compared to that possible during the Apollo program.
A new paradigm for advanced planetary field geology developed through analog experiments on Earth
Field geological research, as traditionally practiced on Earth, is an extremely flexible science. Although field geologists plan their traverses ahead of time—nowadays with the advantage of remote-sensing data—initial plans are continually modified in response to observations, such that traverses evolve over time. This research modality differs from that utilized in extreme environments on Earth (e.g., on the ocean floor), on the Martian surface by the mobile laboratories Spirit and Opportunity , and by the Apollo astronauts during their explorations of the Moon. Harsh and alien conditions, time constraints, and resource limitations have led to the development of operational modes that provide a constrained and usually lower science return than traditional field geology. However, emerging plans for renewed human exploration of the Moon, Mars, and near-Earth asteroids serve as an opportunity to invent a new paradigm for advanced planetary field geology that embraces coordinated human and robotic research activities. This approach will introduce an operational flexibility that is more like that of traditional field geology on Earth. In addition, human and robotic collaborations, combined with the integration of new “smart” tools, should provide an augmented reality that leads to even greater science return than traditional field geology. In order to take full advantage of these opportunities when planetary field geology again becomes practical, it is imperative for field geologists on Earth to begin right now to learn how best to incorporate advanced technologies into their research. Geologic studies of analog sites on Earth that employ new technology-enabled strategies rather than traditional research methods provide ideal opportunities to test and refine emerging designs for advanced planetary field geologic studies, as well as to gain new insights into terrestrial geologic processes. These operational experiments will be most informative if they embrace the entire geologic research process—including problem definition, field observation, and laboratory analysis—and not simply field work. The results of such comprehensive research can be used to inform the design of a maximally effective training regimen for future astronaut explorers.
Geologic field training of the Apollo astronauts and implications for future manned exploration
This paper discusses the philosophy and major aspects of the geology training of the Apollo 15 , 16 , and 17 astronauts. This training concentrated on monthly field trips that were intended to develop the crew's observational skills in recognizing basic geologic structures and rocks and translating observations into an interpretative framework for local geologic evolution. Individual field trips became increasingly mission-like as their training matured. The crews worked with predetermined traverses and progressively added diverse operational aspects, such as proper usage of sampling tools, photo-documentation of pertinent features and rocks, simulation of space-suit mobility, and use of a roving vehicle. These exercises also provided simulations and practice for all major science support functions that would reside in Mission Control during the actual mission. This combined training of surface explorers and ground support will be indispensable in rendering future planetary surface operations as efficient and scientifically rewarding as Apollo .
Training Apollo astronauts in lunar orbital observations and photography
Planning and implementation of astronaut observations and photography from lunar orbit during the Apollo program were based on two expectations: (1) orbiting astronauts would be able to add to our knowledge by describing lunar features from their unique vantage point, and, (2) as illustrated by the Gemini Earth-orbital missions, expertly obtained photographs would allow us to place detailed information from field exploration into a regional context. To achieve these goals, the astronauts had to be thoroughly familiar with concepts of lunar geology and intellectually prepared to note and document the unexpected. This required mission-specific training to add to their store of knowledge about the Moon. Because the activity was not part of the original program objectives, the training was conducted at the behest of the astronauts. The training time grew from occasional briefings on the early flights to extensive classroom sessions and flyover exercises for a formal “experiment” on the last three missions. This chapter summarizes the historical development and salient results of training the Moon-bound astronauts for these tasks. The astronaut-derived orbital observations and photographs increased our knowledge of the Moon beyond that possible from robotic sensors. Outstanding results include: realization of the limitations of photographic film to depict natural lunar surface colors; description and documentation of unknown features on the lunar farside; observation by Apollo 15 of dark-haloed craters that helped in the selection of the Apollo 17 landing site; and real-time confirmation that the “orange soil” discovered at the Apollo 17 site occurs elsewhere on the Moon.
Training astronauts to observe Earth from the space shuttle and International Space Station
Since the beginning of the U.S. space program, the National Aeronautics and Space Administration (NASA) has trained astronauts in basic earth science topics to support their observations of Earth's surface from low Earth orbit. From its roots in the Apollo geology training campaigns, we describe the evolution of astronaut Earth observation training across human spaceflight programs, with a focus on the training for space shuttle and International Space Station (ISS) missions. Astronauts' Earth observation experiences—both preflight training and interactions with scientists on the ground during spaceflight missions—provide relevant information for defining training requirements for future astronaut exploration missions on other planetary surfaces.
Analysis of Antarctic logistics and operations data: Results from the Antarctic Search for Meteorites (ANSMET), austral summer season, 2002–2003, with implications for planetary surface operations
The operational and logistical burden associated with putting a team of four scientists in a hostile environment was investigated as part of the Antarctic Search for Meteorites (ANSMET) Project during the austral summer of 2002–2003. Operational time data, when compared with similar data from the Apollo J-series missions, suggest that crew time available to science on future exploration missions will be no more than 20% of the total available surface time, due to the time demands associated with operating in a hostile environment. A comparison of time-distance statistics derived from ANSMET meteorite search traverses to similar traverses from Apollo was inconclusive—there was no clear pattern of similarity or dissimilarity between the two data sets. However, both data sets reinforce the benefits of robust rover capability over simple walking because rovers allow exploration of a wider area for a given period of time when compared to walking. Lastly, mass data for equipment and supplies for a four-person team on the Antarctic polar plateau suggest that supplying a Mars or lunar mission with the necessary supplies for nominal surface operations would take up a significant amount of the mass-to-orbit prior to initiating trans-Mars or lunar injection.
A historical overview of the Pavilion Lake Research Project—Analog science and exploration in an underwater environment
As humans venture back to the Moon, or onward to near-Earth objects and Mars, it is expected that the rigors of this exploration will far exceed those of Apollo . Terrestrial analogs can play a key role in our preparations for these complex voyages, since in addition to their scientific value, analogs afford the exploration community a means to safely prepare and test exploration strategies for future robotic and human planetary missions. Many relevant analog studies exist, and each is focused on a particular aspect of strategic development. Some analog programs such as the Pavilion Lake Research Project (PLRP) present the opportunity to investigate both real scientific and real exploration scenarios in tandem. The activities of this research program demand the use of techniques, tools, and strategies for underwater scientific exploration, and the challenges associated with the scientific exploration of Pavilion Lake are analogous to those human explorers will encounter on other planetary and small solar system bodies. The goal of this paper is to provide a historical synopsis of the PLRP's objectives, milestones, and contributions to both the scientific and exploration community. Here, we focus on detailing the development and deployment of an integrated science and exploration program with analog application to our understanding of early Earth systems and the preparation for future human space exploration. Over a decade of exploration and discovery is chronicled herein.
Robotic recon for human exploration: Method, assessment, and lessons learned
Robotic rovers can be used as advance scouts to significantly improve scientific and technical return of planetary surface exploration. Robotic scouting, or “robotic recon,” involves using a robot to collect ground-level data prior to human field activity. The data collected and knowledge acquired through recon can be used to refine traverse planning, reduce operational risk, and increase crew productivity. To understand how robotic recon can benefit human exploration, we conducted a series of simulated planetary robotic missions at analog sites. These mission simulations were designed to: (1) identify and quantify operational requirements for robotic recon in advance of human activity; (2) identify and quantify ground control and science team requirements for robotic recon; and (3) identify capability, procedure, and training requirements for human explorers to draw maximum benefit from robotic recon during vehicular traverses and on-foot extravehicular activities (EVA). Our studies indicate that robotic recon can be beneficial to crew, improving preparation, situational awareness, and productivity in the field. This is particularly true when traverse plans contain significant unknowns that can be resolved by recon, such as target access and station/activity priority. In this paper, we first present the assumptions and major questions related to robotic reconnaissance. We detail our system design, including the configuration of our recon robot, the ground data system used for operation, ground control organization, and operational time lines. Finally, we describe the design and results from an experiment to assess robotic recon, discuss lessons learned, and identify directions for future work.
Habitat dust contamination at a Mars analog
After the high-radiation environment and the low gravity field on Mars, dust is arguably the next biggest environmental hazard facing a manned mission to Mars. The seriousness of this threat is still being studied with robotic missions. At its most benign, Martian dust the work undertaken were recorded to study their effects on dust contamination. We found that more than 50 g of dust and soil were transported into the Mars Desert Research Station (MDRS) during the 12 EVAs (extravehicular activities) that were measured. The largest amount of contamination from EVA activity was due to open-cockpit vehicle travel and depended strongly on the terrain over which the EVA was conducted. Based on first-order dust dynamics modeling, similar behaviors are expected on Mars.
The NASA Spaceward Bound field training curriculum
A comprehensive field training curriculum was developed and tested during the 2006, 2008, 2009, and 2010 National Aeronautics and Space Administration (NASA) Spaceward Bound missions at the Mars Desert Research Station (MDRS). The curriculum was developed to train teachers and students in fundamentals of Moon and Mars analog station operations, logistics, field work, and scientific investigation. The curriculum is composed of background content, directions, lesson plans, suggestions, protocols, images, diagrams, figures, checklists, worksheets, experiments, field missions, and references. To date, 48 individuals have participated in Spaceward Bound missions at MDRS, and 18 have successfully tested the curriculum. Based on our analysis and student feedback, we conclude that the Spaceward Bound curriculum is highly useful in training teachers and students in aspects of astrobiology, field science, and Mars exploration, and that MDRS is an ideal location for its use.
We compared the morphology of gully sedimentary fans on Svalbard as possible analogs to gullies on Mars in order to constrain whether fluvial and/or debris-flow processes are predominantly responsible for the formation of Martian gullies. Our analysis is based on high-resolution imagery (High Resolution Stereo Camera [HRSC-AX], ~20 cm/pixel) acquired through a flight campaign in summer 2008 and ground truth during two expeditions in the summers of 2008 and 2009 in Svalbard, compared to high-resolution satellite imagery (High Resolution Imaging Science Experiment [HiRISE], ~25 cm/pixel) from Mars. On Svalbard, fluvial and debris-flow processes are evident in the formation of gullies, but the morphological characteristics clearly show that the transport and sedimentation of eroded material are predominated by debris flows. Most investigated gullies on Mars lack clear evidence for debris-flow processes. The Martian gully fan morphology is more consistent with the deposition of small overlapping fans by multiple fluvial flow events. Clear evidence for debris flows on Mars was only found in one new location, in addition to a few previously published examples. The occurrence of debris-flow processes in the formation of Martian gullies seems to be rare and locally limited. If predominantly fluvial processes caused the formation of gullies on Mars, then large amounts of water would have been required for their formation because of the relatively low sediment supply in stream and/or hyperconcentrated flows. Repeated seasonal or episodic snow deposition and melting during periods of higher obliquity in the recent past on Mars can best explain the formation of the gullies.
Periglacial landscapes on Svalbard: Terrestrial analogs for cold-climate landforms on Mars
We present landforms on Svalbard (Norway) as terrestrial analogs for possible Martian periglacial surface features. While there are closer climatic analogs for Mars, e.g., the Antarctic Dry Valleys, Svalbard has unique advantages that make it a very useful study area. Svalbard is easily accessible and offers a periglacial landscape where many different landforms can be encountered in close spatial proximity. These landforms include thermal contraction cracks, slope stripes, rock glaciers, protalus ramparts, and pingos, all of which have close morphological analogs on Mars. The combination of remote-sensing data, in particular images and digital elevation models, with field work is a promising approach in analog studies and facilitates acquisition of first-hand experience with permafrost environments. Based on the morphological ambiguity of certain landforms such as pingos, we recommend that Martian cold-climate landforms should not be investigated in isolation, but as part of a landscape system in a geological context.
The Tuktoyaktuk Coastlands of northern Canada: A possible “wet” periglacial analog of Utopia Planitia, Mars
Numerous landforms with traits that are suggestive of formation by periglacial processes have been observed in Utopia Planitia, Mars. They include: small-sized polygons, flat-floored depressions, and polygon trough or junction pits. Most workers agree that these landforms are late Amazonian and mark the occurrence of near-surface regolith that is (was) ice rich. The evolution of the Martian landforms has been explained principally by two disparate hypotheses. The first is the “wet hypothesis.” It is derived from the boundary conditions and ice-rich landscape of regions such as the Tuktoyaktuk Coastlands, Canada, where stable liquid water is freely available as an agent of landscape modification. The second is the “dry” hypothesis. It is adapted from the boundary conditions and landscape-modification processes in the glacial Dry Valleys of the Antarctic, where mean temperatures are much colder than in the Tuktoyaktuk Coastlands, liquid water at or near the surface is rare, and sublimation is the principal agent of glacial mass loss. Here, we (1) describe the ice-rich landscape of the Tuktoyaktuk Coastlands and their principal periglacial features; (2) show that these features constitute a coherent assemblage produced by thaw-freeze cycles; (3) describe the landforms of Utopia Planitia and evaluate the extent to which “wet” or “dry” periglacial processes could have contributed to their formation; and (4) suggest that even if questions concerning the “wet” or “dry” origin of the Martian landforms remain open, “dry” processes are incapable of explaining the origin of the ice-rich regolith itself, from which the landforms evolved.
The Jurassic Todilto Formation of NW New Mexico and SW Colorado, USA, has utility as an analog of Martian flood evaporites. The Todilto Formation is a concentrically and vertically zoned carbonate (calcite with minor late dolomite) to sulfate (gypsum) evaporite deposit that developed over a short time span (10 4 –10 5 yr) after rapid flooding of the vast dune field of the Entrada Formation. Within the limits of the very different hydrogeologic environments of Mars and Earth, the Todilto setting of short-lived brine evolution in a largely eolian environment, with terminal formation of a salt hydrate common to both planets (gypsum), provides a useful field area for descriptive and petrogenetic studies of evaporite evolution and interaction with a porous, sandy substrate. The Todilto Formation has an added feature of interest in its association with bituminous materials that have likely microbial precursors, providing a brine-microorganism association that may represent a potential setting for primitive life as might be found on Mars.
Travertine and tufa from Dalhousie Springs (Australia)—Implications for recognizing Martian springs
Thermal spring deposits are features of considerable interest to Mars scientists because of their potential as astrobiological oases and as records of the paleohydrology of the planet. Terrestrial counterparts can assist in recognizing such features on Mars and in developing technologies for their study and sampling. In this paper, we describe one such analog, the Dalhousie Springs complex in central Australia. The Dalhousie Springs complex is one of largest groundwater discharge landforms known on Earth. It is a carbonate-limited precipitation system due to the non-supersaturated ascending water. Spring carbonates are deposited as discrete mounds and outflow channels resting unconformably on older units. Although subject to postformation geomorphic modification, the spring deposits persist in the landscape and are recognizable long after the parental spring has shut down. We identify 14 specific microfacies belonging to seven facies, which form three environmental associations related to specific depositional environments. Diagenesis has occurred in several stages, as evidenced by distinctive textures on the deposits. Spring deposits on Mars would potentially be recognized by similar textures (although compositions may be quite different) and similar geomorphic relationships. However, in satellite images, spring deposits may be difficult to differentiate from deposits resulting from other processes that produce similar geomorphic features, including mud volcanoes, pingos, and rootless cones. Mineralogical data may assist, but ultimately ground truth will be required.
Recent orbital and rover missions to Mars have returned high-resolution images that show complex surface landforms in unprecedented detail. In addition, the spectral data sets from mission instruments reveal the presence of a wide array of mineral species on the surface of Mars. These discoveries are changing the analog science requirements of projects targeting exploration missions to Mars. Mission managers now expect field deployments to include complementary investigations of surface processes, rock types, mineral species, and microbial habitats. Earth-based analog sites are selected according to their potential for integrated geological and biological studies, wherein a central theme is the search for life. Geological field studies on Axel Heiberg Island, in the Canadian Arctic, demonstrate that the Isachsen Formation represents a high-fidelity analog for comparative studies of volcanic terrain on Mars. The two sites of interest are located in structurally complex zones (chaotic terrain) where basaltic lava flows, mafic dikes, and sandstone beds of Early Cretaceous age intersect evaporite outliers at the periphery of the diapirs. At the North Agate Fiord diapir and Junction diapir, remnant blocks of basaltic rock are pervasively altered and contain copper and iron sulfides, as well as the secondary sulfates copiapite, fibroferrite, and jarosite (North Agate Fiord diapir). Alteration zones within poorly consolidated quartzitic sandstone consist of thin layers of goethite, hematite, illite, and jarosite. The sites are morphologically different from Martian patera, but they provide access to volcanic successions and evaporites in areas of permafrost, i.e., conditions that are invoked in conceptual models for hydrothermal systems and groundwater flow on Mars.
Theo's Flow, Ontario, Canada: A terrestrial analog for the Martian nakhlite meteorites
Martian meteorites provide our only samples for laboratory investigations of Mars, yet the lack of geologic context severely limits their utility. Strong petrologic similarities between the pyroxenitic layer of a 120-m-thick, mafic Archean lava flow in Ontario, Canada, called Theo's Flow, and the nakhlite meteorite group may elucidate geologic processes that operated on Mars. Theo's Flow is in the Abitibi greenstone belt, an area that is well known as a komatiite location. The type locality, and best outcrop, of Theo's Flow is an upturned (~70°) section stretching east-west for ~500 m. Theo's Flow can be divided into distinct lithologic units: a thin basal peridotite (0–9 m), a thick pyroxenite (50–60 m), a gabbro (35–40 m), and a hyaloclastic, brecciated top (8–10 m). It is the thick pyroxenitic layer that bears a striking textural similarity to the Martian nakhlites. Serpentinization of olivine, chloritization of orthopyroxene, and alteration (e.g., pseudomorphic replacement) of plagioclase and minor phases have transformed the original mineral assemblage, though augites remain largely unaltered, and textural relationships are well preserved throughout the flow. Variations in iron and minor-element abundances in augite cores exhibit typical trends for an evolving melt. Bulk rock analyses exhibit elemental trends consistent with an evolving melt, though they exhibit evidence of elemental remobilization by later metamorphism. An average of the peridotite, pyroxenite, and gabbro compositions compares well to that of the quenched top hyaloclastite, suggesting it is a single flow that was differentiated by crystal settling. The lithologic diversity within Theo's Flow suggests that nakhlites may also have complementary lithologies that remain unsampled.