The Geologic History of the Hypanis Deposit, Mars and Ballistic Modeling of Lunar Impact Ejecta

157675-Thumbnail Image.png
Description
Water has shaped the surface of Mars, recording previous environments and inspiring the search for extinct life beyond Earth. While conditions on the Martian surface today are not conducive to the presence of liquid water, ancient erosional and depositional features

Water has shaped the surface of Mars, recording previous environments and inspiring the search for extinct life beyond Earth. While conditions on the Martian surface today are not conducive to the presence of liquid water, ancient erosional and depositional features indicate that this was not always so. Quantifying the regional and global history of water on Mars is crucial to understanding how the planet evolved, where to focus future exploration, and implications for water on Earth.

Many sites on Mars contain layered sedimentary deposits, sinuous valleys with delta shaped deposits, and other indications of large lakes. The Hypanis deposit is a unique endmember in this set of locations as it appears to be the largest ancient river delta identified on the planet, and it appears to have no topographic boundary, implying deposition into a sea. I have used a variety of high-resolution remote sensing techniques and geologic mapping techniques to present a new model of past water activity in the region.

I gathered new orbital observations and computed thermal inertia, albedo, elevation, and spectral properties of the Hypanis deposit. I measured the strike and dip of deposit layers to interpret the sedimentary history. My results indicate that Hypanis was formed in a large calm lacustrine setting. My geomorphic mapping of the deposit and catchment indicates buried volatile-rich sediments erupted through the Chryse basin fill, and may be geological young or ongoing. Collectively, my results complement previous studies that propose a global paleoshoreline, and support interpretations that Mars had an ocean early in its history. Future missions to the Martian surface should consider Hypanis as a high-value sampling opportunity.
Date Created
2019
Agent

Differential equation models for understanding phenomena beyond experimental capabilities

Description
Mathematical models are important tools for addressing problems that exceed experimental capabilities. In this work, I present ordinary and partial differential equation (ODE, PDE) models for two problems: Vicodin abuse and impact cratering.

The prescription opioid Vicodin is the nation's

Mathematical models are important tools for addressing problems that exceed experimental capabilities. In this work, I present ordinary and partial differential equation (ODE, PDE) models for two problems: Vicodin abuse and impact cratering.

The prescription opioid Vicodin is the nation's most widely prescribed pain reliever. The majority of Vicodin abusers are first introduced via prescription, distinguishing it from other drugs in which the most common path to abuse begins with experimentation. I develop and analyze two mathematical models of Vicodin use and abuse, considering only those patients with an initial Vicodin prescription. Through adjoint sensitivity analysis, I show that focusing efforts on prevention rather than treatment has greater success at reducing the total population of abusers. I prove that solutions to each model exist, are unique, and are non-negative. I also derive conditions for which these solutions are asymptotically stable.

Verification and Validation (V&V) are necessary processes to ensure accuracy of computational methods. Simulations are essential for addressing impact cratering problems, because these problems often exceed experimental capabilities. I show that the Free Lagrange (FLAG) hydrocode, developed and maintained by Los Alamos National Laboratory, can be used for impact cratering simulations by verifying FLAG against two analytical models of aluminum-on-aluminum impacts at different impact velocities and validating FLAG against a glass-into-water laboratory impact experiment. My verification results show good agreement with the theoretical maximum pressures, and my mesh resolution study shows that FLAG converges at resolutions low enough to reduce the required computation time from about 28 hours to about 25 minutes.

Asteroid 16 Psyche is the largest M-type (metallic) asteroid in the Main Asteroid Belt. Radar albedo data indicate Psyche's surface is rich in metallic content, but estimates for Psyche's composition vary widely. Psyche has two large impact structures in its Southern hemisphere, with estimated diameters from 50 km to 70 km and estimated depths up to 6.4 km. I use the FLAG hydrocode to model the formation of the largest of these impact structures. My results indicate an oblique angle of impact rather than a vertical impact. These results also support previous claims that Psyche is metallic and porous.
Date Created
2019
Agent

Planetary Geological Science and Aerospace Systems Engineering Applications of Thermal Infrared Remote Sensing for Earth, Mars, and the Outer Bodies

156745-Thumbnail Image.png
Description
Many planetary science missions study thermophysical properties of surfaces using infrared spectrometers and infrared cameras. Thermal inertia is a frequently derived thermophysical property that quantifies the ability for heat to exchange through planetary surfaces.

To conceptualize thermal inertia, the diffusion equation

Many planetary science missions study thermophysical properties of surfaces using infrared spectrometers and infrared cameras. Thermal inertia is a frequently derived thermophysical property that quantifies the ability for heat to exchange through planetary surfaces.

To conceptualize thermal inertia, the diffusion equation analogies are extended using a general effusivity term: the square root of a product of conductivity and capacity terms. A hypothetical thermal inductance was investigated for diurnal planetary heating. The hyperbolic heat diffusion equation was solved to derive an augmented thermal inertia. The hypothetical thermal inductance was modeled with negligible effect on Mars.

Extending spectral performance of infrared cameras was desired for colder bodies in the outer solar system where peak infrared emission is at longer wavelengths. The far-infrared response of an infrared microbolometer array with a retrofitted diamond window was determined using an OSIRIS-REx—OTES interferometer. An instrument response function of the diamond interferometer-microbolometer system shows extended peak performance from 15 µm out to 20 µm and 40% performance to at least 30 µm. The results are folded into E-THEMIS for the NASA flagship mission: Europa Clipper.

Infrared camera systems are desired for the expanding smallsat community that can inherit risk and relax performance requirements. The Thermal-camera for Exploration, Science, and Imaging Spacecraft (THESIS) was developed for the Prox-1 microsat mission. THESIS, incorporating 2001 Mars Odyssey—THEMIS experience, consists of an infrared camera, a visible camera, and an instrument computer. THESIS was planned to provide images for demonstrating autonomous proximity operations between two spacecraft, verifying deployment of the Planetary Society’s LightSail-B, and conducting remote sensing of Earth. Prox-1—THESIS was selected as the finalist for the competed University Nanosatellite Program-7 and was awarded a launch on the maiden commercial SpaceX Falcon Heavy. THESIS captures 8-12 µm IR images with 100 mm optics and RGB color images with 25 mm optics. The instrument computer was capable of instrument commanding, automatic data processing, image storage, and telemetry recording. The completed THESIS has a mass of 2.04 kg, a combined volume of 3U, and uses 7W of power. THESIS was designed, fabricated, integrated, and tested in ASU’s 100K clean lab.
Date Created
2018
Agent

The formation and degradation of planetary surfaces: impact features and explosive volcanic landforms on the Moon and Mars

156119-Thumbnail Image.png
Description
Impact cratering and volcanism are two fundamental processes that alter the surfaces of the terrestrial planets. Though well studied through laboratory experiments and terrestrial analogs, many questions remain regarding how these processes operate across the Solar System. Little is known

Impact cratering and volcanism are two fundamental processes that alter the surfaces of the terrestrial planets. Though well studied through laboratory experiments and terrestrial analogs, many questions remain regarding how these processes operate across the Solar System. Little is known about the formation of large impact basins (>300 km in diameter) and the degree to which they modify planetary surfaces. On the Moon, large impact basins dominate the terrain and are relatively well preserved. Because the lunar geologic timescale is largely derived from basin stratigraphic relations, it is crucial that we are able to identify and characterize materials emplaced as a result of the formation of the basins, such as light plains. Using high-resolution images under consistent illumination conditions and topography from the Lunar Reconnaissance Orbiter Camera (LROC), a new global map of light plains is presented at an unprecedented scale, revealing critical details of lunar stratigraphy and providing insight into the erosive power of large impacts. This work demonstrates that large basins significantly alter the lunar surface out to at least 4 radii from the rim, two times farther than previously thought. Further, the effect of pre-existing topography on the degradation of impact craters is unclear, despite their use in the age dating of surfaces. Crater measurements made over large regions of consistent coverage using LROC images and slopes derived from LROC topography show that pre-existing topography affects crater abundances and absolute model ages for craters up to at least 4 km in diameter.

On Mars, small volcanic edifices can provide valuable insight into the evolution of the crust and interior, but a lack of superposed craters and heavy mantling by dust make them difficult to age date. On Earth, morphometry can be used to determine the ages of cinder cone volcanoes in the absence of dated samples. Comparisons of high-resolution topography from the Context Imager (CTX) and a two-dimensional nonlinear diffusion model show that the forms observed on Mars could have been created through Earth-like processes, and with future work, it may be possible to derive an age estimate for these features in the absence of superposed craters or samples.
Date Created
2018
Agent

Driven by affect to explore asteroids, the Moon, and science education

155943-Thumbnail Image.png
Description
Affect is a domain of psychology that includes attitudes, emotions, interests, and values. My own affect influenced the choice of topics for my dissertation. After examining asteroid interiors and the Moon’s thermal evolution, I discuss the role of affect in

Affect is a domain of psychology that includes attitudes, emotions, interests, and values. My own affect influenced the choice of topics for my dissertation. After examining asteroid interiors and the Moon’s thermal evolution, I discuss the role of affect in online science education. I begin with asteroids, which are collections of smaller objects held together by gravity and possibly cohesion. These “rubble-pile” objects may experience the Brazil Nut Effect (BNE). When a collection of particles of similar densities, but of different sizes, is shaken, smaller particles will move parallel to the local gravity vector while larger objects will do the opposite. Thus, when asteroids are shaken by impacts, they may experience the BNE as possibly evidenced by large boulders seen on their surfaces. I found while the BNE is plausible on asteroids, it is confined to only the outer layers. The Moon, which formed with a Lunar Magma Ocean (LMO), is the next topic of this work. The LMO is due to the Moon forming rapidly after a giant impact between the proto-Earth and another planetary body. The first 80% of the LMO solidified rapidly at which point a floatation crust formed and slowed solidification of the remaining LMO. Impact bombardment during this cooling process, while an important component, has not been studied in detail. Impacts considered here are from debris generated during the formation of the Moon. I developed a thermal model that incorporates impacts and find that impacts may have either expedited or delayed LMO solidification. Finally, I return to affect to consider the differences in attitudes towards science between students enrolled in fully-online degree programs and those enrolled in traditional, in-person degree programs. I analyzed pre- and post-course survey data from the online astrobiology course Habitable Worlds. Unlike their traditional program counterparts, students enrolled in online programs started the course with better attitudes towards science and also further changed towards more positive attitudes during the course. Along with important conclusions in three research fields, this work aims to demonstrate the importance of affect in both scientific research and science education.
Date Created
2017
Agent

Adaptive Technologies using Soft Robotic Bladders

Description
The traditional understanding of robotics includes mechanisms of rigid structures, which can manipulate surrounding objects, taking advantage of mechanical actuators such as motors and servomechanisms. Although these methods provide the underlying fundamental concepts behind much of modern technological infrastructure, in

The traditional understanding of robotics includes mechanisms of rigid structures, which can manipulate surrounding objects, taking advantage of mechanical actuators such as motors and servomechanisms. Although these methods provide the underlying fundamental concepts behind much of modern technological infrastructure, in fields such as manufacturing, automation, and biomedical application, the robotic structures formed by rigid axels on mechanical actuators lack the delicate differential sensors and actuators associated with known biological systems. The rigid structures of traditional robotics also inhibit the use of simple mechanisms in congested and/or fragile environments. By observing a variety of biological systems, it is shown that nature models its structures over millions of years of evolution into a combination of soft structures and rigid skeletal interior supports. Through technological bio-inspired designs, researchers hope to mimic some of the complex behaviors of biological mechanisms using pneumatic actuators coupled with highly compliant materials that exhibit relatively large reversible elastic strain. This paper begins the brief history of soft robotics, the various classifications of pneumatic fluid systems, the associated difficulties that arise with the unpredictable nature of fluid reactions, the methods of pneumatic actuators in use today, the current industrial applications of soft robotics, and focuses in large on the construction of a universally adaptable soft robotic gripper and material application tool. The central objective of this experiment is to compatibly pair traditional rigid robotics with the emerging technologies of sort robotic actuators. This will be done by combining a traditional rigid robotic arm with a soft robotic manipulator bladder for the purposes of object manipulation and excavation of extreme environments.
Date Created
2016-05
Agent

Hopping Mobility Mechanism for Robotic Exploration of Lunar Lava Pits

136181-Thumbnail Image.png
Description
A robotic exploration mission that would enter a lunar pit to characterize the environment is described. A hopping mechanism for the robot's mobility is proposed. Various methods of hopping drawn from research literature are discussed in detail. The feasibilities of

A robotic exploration mission that would enter a lunar pit to characterize the environment is described. A hopping mechanism for the robot's mobility is proposed. Various methods of hopping drawn from research literature are discussed in detail. The feasibilities of mechanical, electric, fluid, and combustive methods are analyzed. Computer simulations show the mitigation of the risk of complex autonomous navigation systems. A mechanical hopping mechanism is designed to hop in Earth gravity and carry a payload half its mass. A physical experiment is completed and proves a need for further refinement of the prototype design. Future work is suggested to continue exploring hopping as a mobility method for the lunar robot.
Date Created
2015-05
Agent

A Cubesat Centrifuge for Long Duration Milligravity Research

128142-Thumbnail Image.png
Description

We advocate a low-cost strategy for long-duration research into the ‘milligravity’ environment of asteroids, comets and small moons, where surface gravity is a vector field typically less than 1/1000 the gravity of Earth. Unlike the microgravity environment of space, there

We advocate a low-cost strategy for long-duration research into the ‘milligravity’ environment of asteroids, comets and small moons, where surface gravity is a vector field typically less than 1/1000 the gravity of Earth. Unlike the microgravity environment of space, there is a directionality that gives rise, over time, to strangely familiar geologic textures and landforms. In addition to advancing planetary science, and furthering technologies for hazardous asteroid mitigation and in situ resource utilization, simplified access to long-duration milligravity offers significant potential for advancing human spaceflight, biomedicine and manufacturing. We show that a commodity 3U (10 × 10 × 34 cm3) cubesat containing a laboratory of loose materials can be spun to 1 r.p.m. = 2π/60 s-1 on its long axis, creating a centrifugal force equivalent to the surface gravity of a kilometer-sized asteroid. We describe the first flight demonstration, where small meteorite fragments will pile up to create a patch of real regolith under realistic asteroid conditions, paving the way for subsequent missions where landing and mobility technology can be flight-proven in the operational environment, in low-Earth orbit. The 3U design can be adapted for use onboard the International Space Station to allow for variable gravity experiments under ambient temperature and pressure for a broader range of experiments.

Date Created
2017-06-05
Agent

Sesquinary Catenae on the Martian Satellite Phobos From Reaccretion of Escaping Ejecta

128509-Thumbnail Image.png
Description

The Martian satellite Phobos is criss-crossed by linear grooves and crater chains whose origin is unexplained. Anomalous grooves are relatively young, and crosscut tidally predicted stress fields as Phobos spirals towards Mars. Here we report strong correspondence between these anomalous

The Martian satellite Phobos is criss-crossed by linear grooves and crater chains whose origin is unexplained. Anomalous grooves are relatively young, and crosscut tidally predicted stress fields as Phobos spirals towards Mars. Here we report strong correspondence between these anomalous features and reaccretion patterns of sesquinary ejecta from impacts on Phobos. Escaping ejecta persistently imprint Phobos with linear, low-velocity crater chains (catenae) that match the geometry and morphology of prominent features that do not fit the tidal model. We prove that these cannot be older than Phobos’ current orbit inside Mars’ Roche limit. Distinctive reimpact patterns allow sesquinary craters to be traced back to their source, for the first time across any planetary body, creating a novel way to probe planetary surface characteristics. For example, we show that catena-producing craters likely formed in the gravity regime, providing constraints on the ejecta velocity field and knowledge of source crater material properties.

Date Created
2016-08-30
Agent

Design and development of rolling and hopping ball robots for low gravity environment

154629-Thumbnail Image.png
Description
In-situ exploration of planetary bodies such as Mars or the Moon have provided geologists and planetary scientists a detailed understanding of how these bodies formed and evolved. In-situ exploration has aided in the quest for water and life-supporting chemicals.

In-situ exploration of planetary bodies such as Mars or the Moon have provided geologists and planetary scientists a detailed understanding of how these bodies formed and evolved. In-situ exploration has aided in the quest for water and life-supporting chemicals. In-situ exploration of Mars carried out by large SUV-sized rovers that travel long distance, carry sophisticated onboard laboratories to perform soil analysis and sample collection. But their large size and mobility method prevents them from accessing or exploring extreme environments, particularly caves, canyons, cliffs and craters.

This work presents sub- 2 kg ball robots that can roll and hop in low gravity environments. These robots are low-cost enabling for one or more to be deployed in the field. These small robots can be deployed from a larger rover or lander and complement their capabilities by performing scouting and identifying potential targets of interest. Their small size and ball shape allow them to tumble freely, preventing them from getting stuck. Hopping enables the robot to overcome obstacles larger than the size of the robot.

The proposed ball-robot design consists of a spherical core with two hemispherical shells with grouser which act as wheels for small movements. These robots have two cameras for stereovision which can be used for localization. Inertial Measurement Unit (IMU) and wheel encoder are used for dead reckoning. Communication is performed using Zigbee radio. This enables communication between a robot and a lander/rover or for inter-robot communication. The robots have been designed to have a payload with a 300 gram capacity. These may include chemical analysis sensors, spectrometers and other small sensors.

The performance of the robot has been evaluated in a laboratory environment using Low-gravity Offset and Motion Assistance Simulation System (LOMASS). An evaluation was done to understand the effect of grouser height and grouser separation angle on the performance of the robot in different terrains. The experiments show with higher grouser height and optimal separation angle the power requirement increases but an increase in average robot speed and traction is also observed. The robot was observed to perform hops of approximately 20 cm in simulated lunar condition. Based on theoretical calculations, the robot would be able to perform 208 hops with single charge and will operate for 35 minutes. The study will be extended to operate multiple robots in a network to perform exploration. Their small size and cost makes it possible to deploy dozens in a region of interest. Multiple ball robots can cooperatively perform unique in-situ science measurements and analyze a larger surface area than a single robot alone on a planet surface.
Date Created
2016
Agent