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At least 1,135 records · Page 63

Testing Mars Exploration Rover-Inspired Operational Strategies for Semi-Autonomous Rovers on the Moon Ii: the GeoHeuristic Operational Strategies Test in Alaska

We used MER-derived semi-autonomous rover science operations strategies to determine best practices suitable for remote semi-autonomous lunar rover geology. Two field teams studied two glacial moraines as analogs for potential ice-bearing lunar regolith. At each site a Rover Team commanded a human rover to execute observations based on common MER sequences; the resulting data were used to identify and characterize targets of interest. A Tiger Team followed the Rover Team using traditional terrestrial field methods, and the results of the two teams were compared. Narrowly defined goals that can be addressed using cm-scale or coarser resolution may be met sufficiently by the operational strategies adapted from MER survey mode. When reconnaissance is the primary goal, the strategies tested are necessary but not sufficient. Further, there may be a set of optimal observations for such narrowly defined, hypothesis-driven science goals, such that collecting further data would result in diminishing returns. We confirm results of previous tests that indicated systematic observations might improve efficiency during strategic planning, and improve science output during data analysis. This strategy does not markedly improve the rate at which a science team can ingest data to feed back into tactical decision-making. Other methods should be tested to separate the strategic and tactical processes, and to build in time for data analysis.

MER↗

INL Operations Improvements of Nuclear Enabled Missions for NASA - Presentation

The Idaho National laboratory (INL) has supported NASA missions integrate nuclear power systems since the Department of Energy (DOE) moved the Radioisotope Power Systems (RPS) program in 2002 from Mound, Ohio to the Materials and Fuels Complex, INL (Argonne National Laboratory West (ANL-W) prior to 2005). This paper discusses the evolution of INL operations improvements made at INL and KSC throughout the Mars Exploratory Rovers, New Horizons, Mars Science Laboratory, and Mars 2020 missions.

99 GENERAL AND MISCELLANEOUS↗

Observed Correlation Between Local Topography and Passive Neutron Measurements from the Dynamic Albedo of Neutrons (DAN) Instrument on the Mars Science Laboratory (MSL) Rover

The Dynamic Albedo of Neutrons (DAN) instrument on the Mars Science Laboratory Curiosity rover primarily measures neutrons that have undergone interactions with rocks and materials in the rover's local environment. As the rover ascends Aeolis Mons, it may encounter more extreme local topography (e.g., cliffs, gullies, canyons). We present three parts of the rover's traverse in which local topography, expressed as the average local relief relative to the rover, is moderately to strongly correlated with an increase in passive thermal neutron count rates. These increases in count rates are consistent with results from radiation transport models of the instrument's performance near simulated topographic features. Additional DAN measurements in areas of high average local relief (>0.25 m) within 5 m of the instrument could bolster this correlation. DAN's sensitivity to topography in its passive mode could be utilized as a new measurement capability and has implications for the operation of future landed missions carrying neutron spectrometers (e.g., VIPER, MoonRanger, Lunar-VISE).

Steven D Dibb↗

Lunar and Planetary Science XXXV: Mars Missions

The session "Mars Missions" included the following reports:Future Planetary Surface Imager Development by the Beagle 2 Stereo Camera System Team; Localization, Localization, Localization; Preliminary Assessment of Mars Exploration Rover Landing Site Predictions; Spirit at Gusev Crater: Preliminary Observations, Potential Processes and Hypotheses; MER Field Geologic Traverse in Gusev Crater, Mars: Initial Results From the Perspective of Spirit; Coordinated Observations of Aeolian Features from the Mars Exploration Rovers (MER) and the Mars Express High Resolution Stereo Camera and Other Orbiters; Soil and Rock Physical Properties at the Mars Exploration Rover Landing Sites: Early Returns; Transient Liquid Water as a Mechanism for Induration of Soil Crusts on Mars; First Results of the Athena Microscopic Imager Investigation; APXS on Mars: Analyses of Soils and Rocks at Gusev Crater and Meridiani Planum; Mars Exploration Rover Panoramic Camera Multidimensional Analyses and Surface Spectral Variability ; Hematite at Meridiani Planum: Detailed Spectroscopic Observations and Testable Hypotheses; Maussbauer Spectroscopy of Soils and Rocks at Gusev Crater and Meridiani Planum; and Student Interns Work on Mars.

Source record↗

Ultraviolet Testing of Space Suit Materials for Mars

Human missions to Mars may require radical changes in the approach to extra-vehicular (EVA) suit design. A major challenge is the balance of building a suit robust enough to complete multiple EVAs under intense ultraviolet (UV) light exposure without losing mechanical strength or compromising the suit's mobility. To study how the materials degrade on Mars in-situ, the Jet Propulsion Laboratory (JPL) invited the Advanced Space Suit team at NASA's Johnson Space Center (JSC) to place space suit materials on the Scanning Habitable Environments with Raman & Luminescence for Organics and Chemicals (SHERLOC) instrument's calibration target of the Mars 2020 rover. In order to select materials for the rover and understand the effects from Mars equivalent UV exposure, JSC conducted ground testing on both current and new space suit materials when exposed to 2500 hours of Mars mission equivalent UV. To complete this testing, JSC partnered with NASA's Marshall Space Flight Center to utilize their UV vacuum chambers. Materials tested were Orthofabric, polycarbonate, Teflon, Dacron, Vectran, spectra, bladder, nGimat coated Teflon, and nGimat coated Orthofabric. All samples were measured for mass, tensile strength, and chemical composition before and after radiation. Mass loss was insignificant (less than 0.5%) among the materials. Most materials loss tensile strength after radiation and became more brittle with a loss of elongation. Changes in chemical composition were seen in all radiated materials through Spectral Analysis. Results from this testing helped select the materials that will fly on the Mars 2020 rover. In addition, JSC can use this data to create a correlation to the chemical changes after radiation-which is what the rover will send back while on Mars-to the mechanical changes, such as tensile strength.

Larson, Kristine↗

Ultraviolet Testing of Space Suit Materials for Mars

Human missions to Mars may require radical changes in the approach to extra-vehicular (EVA) suit design. A major challenge is the balance of building a suit robust enough to complete multiple EVAs under intense ultraviolet (UV) light exposure without losing mechanical strength or compromising the suit's mobility. To study how the materials degrade on Mars in-situ, the Jet Propulsion Laboratory (JPL) invited the Advanced Space Suit team at NASA's Johnson Space Center (JSC) to place space suit materials on the Scanning Habitable Environments with Raman & Luminescence for Organics and Chemicals (SHERLOC) instrument's calibration target of the Mars 2020 rover. In order to select materials for the rover and understand the effects from Mars equivalent UV exposure, JSC conducted ground testing on both current and new space suit materials when exposed to 2500 hours of Mars mission equivalent UV. To complete this testing, JSC partnered with NASA's Marshall Space Flight Center to utilize their UV vacuum chambers. Materials tested were Orthofabric, polycarbonate, Teflon, Dacron, Vectran, spectra, bladder, nGimat coated Teflon, and nGimat coated Orthofabric. All samples were measured for mass, tensile strength, and chemical composition before and after radiation. Mass loss was insignificant (less than 0.5%) among the materials. Most materials loss tensile strength after radiation and became more brittle with a loss of elongation. Changes in chemical composition were seen in all radiated materials through Spectral Analysis. Results from this testing helped select the materials that will fly on the Mars 2020 rover. In addition, JSC can use this data to create a correlation to the chemical changes after radiation-which is what the rover will send back while on Mars-to the mechanical changes, such as tensile strength.

Larson, Kristine↗

Mars 2020 Thermal Protection Systems Sizing and Development

The Mars 2020 spacecraft delivering the Perseverance Rover to Mars was planned to be a build-to-print repeat of the Mars Science Laboratory (MSL) spacecraft that delivered the Curiosity Rover to Mars in 2012. The 2020 mission would deliver a slightly higher mass at a lower entry velocity, so the mission designers were comfortable with the cost saving approach of using an already proven design. The approach used in sizing the thermal protection systems (TPS) for the various components of the MSL spacecraft included convective heating and shock layer radiation (a small contributor) on the heatshield and only convective heating on all of the aft body parts. At the time, it was assumed that the contribution of radiation from the shock layer and the wake was negligible on the aft body at Mars. In the time since the MSL spacecraft was designed, in light of new data and analysis, NASA realized the significance of radiative heating in the aftbody on vehicles entering Mars, beginning with the InSight entry. New analyses showed that the radiant heat fluxes on aft body components at Mars were of the same order or even larger than predicted convective heat fluxes. The Mars 2020 team was tasked with showing that the TPS thicknesses designed for MSL with only convective heating would survive the Mars 2020 convective plus radiative heat flux environments. Luckily, many of the MSL aft body components were sized using an extra conservative approach, often sizing for the worst environment at the lightest, thinnest structure, even though the environments and structures were not co-located. The Mars 2020 team had to more accurately evaluate the environments and structures to show that the design would close

Mars Entry↗

Volatiles and Isotopes and the Exploration of Ancient and Modern Martian Habitability with the Curiosity Rover

The Mars Science Laboratory Mission was designed to pave the way for the study of life beyond Earth through a search for a habitable environment in a carefully selected landing site on Mars. Its ongoing exploration of Gale Crater with the Curiosity Rover has provided a rich data set that revealed such an environment in an ancient lakebed [1]. Volatile and isotope measurements of both the atmosphere and solids contribute to our growing understanding of both modern and ancient environments.

curiosity rover↗

The Spirit Rover's Athena science investigation at Gusev Crater, Mars

The Mars Exploration Rover Spirit and its Athena science payload have been used to investigate a landing site in Gusev crater. Gusev is hypothesized to be the site of a former lake, but no clear evidence for lacustrine sedimentation has been found to date. Instead, the dominant lithology is basalt, and the dominant geologic processes are impact events and eolian transport. Many rocks exhibit coatings and other characteristics that may be evidence for minor aqueous alteration. Any lacustrine sediments that may exist at this location within Gusev apparently have been buried by lavas that have undergone subsequent impact disruption.

Mars↗

The Opportunity Rover's Athena science investigation at Meridiani Planum, Mars

The Mars Exploration Rover Opportunity has investigated the landing site in Eagle crater and the nearby plains within Meridiani Planum. The soils consist of fine-grained basaltic sand and a surface lag of hematite-rich spherules, spherule fragments, and other granules. Wind ripples are common. Underlying the thin soil layer, and exposed within small impact craters and troughs, are flat-lying sedimentary rocks. These rocks are finely laminated, are rich in sulfur, and contain abundant sulfate salts. Small-scale cross-lamination in some locations provides evidence for deposition in flowing liquid water. We interpret the rocks to be a mixture of chemical and siliciclastic sediments formed by episodic inundation by shallow surface water, followed by evaporation, exposure, and desiccation. Hematite-rich spherules are embedded in the rock and eroding from them. We interpret these spherules to be concretions formed by postdepositional diagenesis, again involving liquid water.

Mars↗

Rover Technology Development and Infusion for the 2009 Mars Science Laboratory Mission

After the 2003 Mars Exploration Rovers (MER) Mission, NASA plans to send a larger, longer life Mobile Science Laboratory (MSL) in 2009. This rover is planned to last 500 days, travel ten kilometers, and demonstrate autonomous capabilities that reduce the number of communication cycles now needed to achieve successful completion of activities on the surface.

spacecraft autonomy planetary robotics technology ↗

Cementation and Aqueous Alteration of a Sandstone Unit Under Acidic Conditions in Gale Crater, Mars

The Curiosity rover landed on Mars in August 2012 to explore the sedimentary history and to assess the habitability of Gale Crater. After 1200 sols of surface operations and over 12 km of traverse distance, the mineralogy of 10 samples has been determined by the CheMin X-ray diffractometer (XRD) and the chemical composition of nearly 300 targets has been established by the Alpha Particle X-ray Spectrometer (APXS). Light-toned fracture zones containing elevated concentrations of silica have been studied by Curiosity's instruments to determine the nature of the fluids that resulted in the enrichment of SiO2. Multiple fluid exposures are evident, and the chemistry and mineralogy data indicate at least two aqueous episodes may have occurred under acidic conditions.

Yen, A. S.↗

The impact of Mars surface characteristics on rover design

The characteristics of the surface of Mars will have a profound effect on the design and operation of roving vehicles. The design impacts of surface conditions, and the implications of knowing these conditions well or poorly, are described. It is a clear benefit to have orbital imaging, and radar subsurface sounding data at a scale of about one meter before designing the rover. In addition, knowledge of the terrain to one meter scale is important for efficient traverse and operations planning.

Pivirotto, Donna L. S.↗

Exploring Mars with Balloons and Inflatable Rovers

Until now, the exploration of Mars has taken place with global coverage of the planet by satellites in orbit or with landers providing very detailed coverage of extremely limited local areas. New developments in inflatable technology, however, now offer the possibility of in situ surface and atmospheric global studies of Mars using very lightweight rovers and balloons that can travel hundreds or even thousands of kilometers relatively quickly and safely. Both systems are currently being tested at JPL; preliminary results show great promise. One of the balloon technologies offers the additional bonus of being able to land payloads on Mars much more gently than parachutes, yet with considerably less mass.

Jones, Jack A.↗

The Mars Exploration Rover/Collaborative Information Portal

Astrology has long argued that the alignment of the planets governs human affairs. Science usually scoffs at this. There is, however, an important exception: sending spacecraft for planetary exploration. In late May and early June, 2003, Mars will be in position for Earth launch. Two Mars Exploration Rovers (MER) will rocket towards the red planet. The rovers will perform a series of geological and meteorological experiments, seeking to examine geological evidence for water and conditions once favorable for life. Back on earth, a small army of surface operations staff will work to keep the rovers running, sending directions for each day's operations and receiving the files encoding the outputs of the Rover's six instruments. (Mars is twenty light minutes from Earth. The rovers must be robots.) The fundamental purpose of the project is, after all, Science. Scientists have experiments they want to run. Ideally, scientists want to be immediately notified when the data products of their experiments have been received, so that they can examine their data and (collaboratively) deduce results. Mars is an unpredictable environment. We may issue commands to the rovers but there is considerable uncertainty in how the commands will be executed and whether what the rovers sense will be worthy of further pursuit. The steps of what is, to a scientist, conceptually an individual experiment may be scattered over a large number of activities. While the scientific staff has an overall strategic idea of what it would like to accomplish, activities are planned daily. The data and surprises of the previous day need to be integrated into the negotiations for the next day's activities, all synchronized to a schedule of transmission windows . Negotiations is the operative term, as different scientists want the resources to run possibly incompatible experiments. Many meetings plan each day's activities.

Walton, Joan↗