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At least 865 records · Page 48

Upper Torso Control for HOAP-2 Using Neural Networks

Humanoid robots have similar physical builds and motion patterns as humans. Not only does this provide a suitable operating environment for the humanoid but it also opens up many research doors on how humans function. The overall objective is replacing humans operating in unsafe environments. A first target application is assembly of structures for future lunar-planetary bases. The initial development platform is a Fujitsu HOAP-2 humanoid robot. The goal for the project is to demonstrate the capability of a HOAP-2 to autonomously construct a cubic frame using provided tubes and joints. This task will require the robot to identify several items, pick them up, transport them to the build location, then properly assemble the structure. The ability to grasp and assemble the pieces will require improved motor control and the addition of tactile feedback sensors. In recent years, learning-based control is becoming more and more popular; for implementing this method we will be using the Adaptive Neural Fuzzy Inference System (ANFIS). When using neural networks for control, no complex models of the system must be constructed in advance-only input/output relationships are required to model the system.

Sandoval, Steven P.↗

Compositional Impact of Io Volcanic Emissions on Jupiter's Magnetosphere and the Icy Galilean Moons

The magnetospheric ion population of Jupiter is dominated by the 1000 kg/s of iogenic material constantly ejected by IO volcanism as neutral gas (approx. 1 kg/s goes out as high speed dust grains), subsequent atmospheric losses to the IO torus, and radial transport of torus ions throughout the magnetosphere. As that magnetosphere is greatly distended in radial size by the iogenic plasma loading, so are surfaces of the other Galilean moons also significantly, and perhaps even dominantly, affected by iogenic plasma bombardment, e.g. at the level up to 0.2 kg/s heavy ions (mostly O and S) onto Europa as per local plasma ion measurements. In comparison, cometary impacts onto IO deliver about 0.02 kg/s of impact ejecta to Europa via ballistic transfer through the Jupiter system. The magnetosphere of this system operates as a powerful engine to produce and transport ions from the IO source to the surfaces of these other moons, and any future orbiter missions to these moons must account for surface distributions of the iogenic material and its chemical effects before real assessments can be made of sensible chemical materials otherwise arising from primordial formation and subsequent evolution of these moons. This is a fundamental problem of space weathering that must be addressed for all planetary bodies with thin atmospheres and direct surface exposure to their space plasma environments. Long-standing debates from Galileo Orbiter measurements about the origins of hydrate sulfates at Europa present examples of this problem, as to whether the sulfates arise from oceanic minerals or from iogenic sulfur chemistry. Any orbiter or landed mission to Europa for astrobiological investigations would further need to separate the potential chemical biosignatures of life or its precursors from the highly abundant background of iogenic material. Although no single ion carries a tag identifying it as of iogenic or other origin, the elemental abundance distributions of ions to be measured throughout the jovian magnetosphere and in the local moon environments can act as tracers if we know from direct measurements and models the distributions at the mostly likely sources, i.e. at IO. However, our knowledge of these abundances are very limited from earlier in-situ and remote measurements, mainly confined to major (S, O) and some minor (Na, K, Cl) species with abundances at or above a few percent relative to O. Future in-situ plasma measurements by the planned Jupiter Europa Orbiter and Jupiter Ganymede Orbiter missions should extend the abundance coverage to minor and even trace elemental species. For Europa astrobiological investigations it is also important to specify iogenic inputs and surface processing of isotopic species. We discuss the range of abundance distributions arising from models for IO hot volcanic emissions, and from the subsequent dynamics of ion injection, magnetospheric transport, and icy moon surface bombardment.

Cooper, John↗

The Habitability of Proxima Centauri b: Environmental States and Observational Discriminants

Proxima Centauri b provides an unprecedented opportunity to understand the evolution and nature of terrestrial planets orbiting M dwarfs. Although Proxima Cen b orbits within its star’s habitable zone, multiple plausible evolutionary paths could have generated different environments that may or may not be habitable. Here, we use 1-D coupled climate-photochemical models to generate self-consistent atmospheres for several evolutionary scenarios, including high-O2, high-CO2, and more Earth-like atmospheres, with both oxic and anoxic compositions. We show that these modeled environments can be habitable or uninhabitable at Proxima Cen b's position in the habitable zone. We use radiative transfer models to generate synthetic spectra and thermal phase curves for these simulated environments, and use instrument models to explore our ability to discriminate between possible planetary states. These results are applicable not only to Proxima Cen b but to other terrestrial planets orbiting M dwarfs. Thermal phase curves may provide the first constraint on the existence of an atmosphere. We find that James Webb Space Telescope ( JWST) observations longward of 10 mm could characterize atmospheric heat transport and molecular composition. Detection of ocean glint is unlikely with JWST but may be within the reach of larger-aperture telescopes. Direct imaging spectra may detect O4 absorption, which is diagnostic of massive water loss and O2 retention, rather than a photosynthetic biosphere. Similarly, strong CO2 and CO bands at wavelengths shortward of 2.5 mm would indicate a CO2-dominated atmosphere. If the planet is habitable and volatile-rich, direct imaging will be the best means of detecting habitability. Earth-like planets with microbial biospheres may be identified by the presence of CH4-which has a longer atmospheric lifetime under Proxima Centauri's incident UV-and either photosynthetically produced O2 or a hydrocarbon haze layer.

Meadows, Victoria S.↗

Spaceflight Microbiology

Microbiological Areas of Concern: Astronaut Health; Vehicle integrity; Life support and other systems failure -Biofilm formation/biofouling -Bio-corrosion and biodegradation -Trash and human waste containment -Risk of condensation -Astronaut hygiene areas; Spaceflight foods -Impact of “pick and eat” foods on the environment -Impact of the environment on “pick and eat” foods -Rinsing food with potable water is impractical; Planetary protection -How do we track what we are leaving versus what we are finding in our search for life on other planets?

Ott, C. Mark↗

The Stardust Sample Return Mission

Stardust was a Discovery class NASA mission that successfully collected dust from the coma of a Jupiter family comet, 81P/Wild 2, and returned it to Earth in 2006 for study in terrestrial laboratories. Study of the returned samples revolutionized our understanding of the nature of the materials involved in comet formation. They demonstrated that comets contain a diverse set of materials that originated from numerous locations in the protosolar disk, were mixed together and assembled into a cometary parent body, and subsequently stored in a manner that resulted in very little parent body alteration. They represent a snapshot of the diversity of processes, environments, and materials present during the early stages of the formation of our planetary system.

organics↗

Design comparison of lunar return configurations

Parabolic manned re-entry design comparisons are made between two classes of slender and blunt configurations capable of conventional horizontal and vertical earth landings. Aerodynamic modulation using flaps and control augmentation requirements are discussed in terms of their effect upon re-entry trajectories and landing footprints. Within the environment defined by the re-entry trajectories, the convective and radiative modes of heat transfer are compared, their differences discussed, and the problems associated with the configurations for planetary return missions indicated. Thermal protection systems are discussed and the factors influencing the selection of a given system for the re-entry environment are indicated. Comparison between reflective and absorptive systems are made and the merits of each for a given flight time indicated. A thermo-structural analysis is presented which shows the trade-oft between structural operating temperature and heat protection system thickness requirements. Total heat shield and structural weights are compared for the landing footprints presented and their variation with range shown. Finally, the areas of uncertainty in the aero-thermo structural design analysis are indicated for each class of configuration studied, and the weight differences between conventional horizontal landing and vertical descent configurations are given.

Parabolic flight↗

Maintainability of unmanned planetary spacecraft - A JPL perspective

The challenge posed by the need for autonomous repair of unmanned spacecraft in unattended environments in outer space is addressed. The redundancy philosophy which forms a fundamental design driver for recent JPL interplanetary spacecraft is reviewed, and the requirements for autonomous spacecraft operations are described. Autonomous fault detection and correction is discussed, and in-flight experiences with fault correction during the VO and VGR missions are described. The lessons learned from these experiences are reviewed.

Kobele, P.↗

Analysis of Bioreduction Strategies for a Solid Rocket Motor on an Interplanetary Mission to Europa

The Europa Lander De-Orbit stage braking motor must comply with the Planetary Protection requirements established for a category IV mission. In its mission to Europa, a motor that hasn’t gone through bioreduction environments will carry microbial spores and other biosignature molecules that might jeopardize a mission of astrobiological concern as well as future missions to come. A motor with solid rocket propellant represents exclusive challenges associated to the calculation of high numbers of an encapsulated bioburden hidden behind a nozzle plug. Existing techniques for bioburden reduction are analysed in perspective to motor assembly facilities and the series of events that are involved in manufacturing a solid rocket motor. These techniques include antimicrobial effects of chemical components already present within the motor and bioreduction due to assembly and operational environments induced in the motor. Analysis of the manufacturing process, adhered bioburden and recent investigations into the effectiveness of microbiological techniques in finding inherent antimicrobial properties have generated a step by step outline of Planetary Protection for lander mission associated solid rocket motors.

Velez-Justiniano, Yo-Ann↗

A Virtual Collaborative Environment for Mars Surveyor Landing Site Studies

Over the past year and a half, the Center for Mars Exploration (CMEX) at NASA Ames Research Center (ARC) has been working with the Mars Surveyor Project Office at JPL to promote interactions among the planetary community and to coordinate landing site activities for the Mars Surveyor Project Office. To date, CMEX has been responsible for organizing the first two Mars Surveyor Landing Site workshops, web-archiving resulting information from these workshops, aiding in science evaluations of candidate landing sites, and serving as a liaison between the community and the Project. Most recently, CMEX has also been working with information technologists at Ames to develop a state-of-the-art collaborative web site environment to foster interaction of interested members of the planetary community with the Mars Surveyor Program and the Project Office. The web site will continue to evolve over the next several years as new tools and features are added to support the ongoing Mars Surveyor missions.

Gulick, V.C.↗

A Virtual Collaborative Environment for Mars Surveyor Landing Site Studies

Over the past year and a half, the Center for Mars Exploration (CMEX) at NASA Ames Research Center (ARC) has been working with the Mars Surveyor Project Office at JPL to promote interactions among the planetary community and to coordinate landing site activities for the Mars Surveyor Project Office. To date, CMEX has been responsible for organizing the first two Mars Surveyor Landing Site workshops, web-archiving resulting information from these workshops, aiding in science evaluations of candidate landing sites, and serving as a liaison between the community and the Project. Most recently, CMEX has also been working with information technologists at Ames to develop a state-of-the-art collaborative web site environment to foster interaction of interested members of the planetary community with the Mars Surveyor Program and the Project Office. The web site will continue to evolve over the next several years as new tools and features are added to support the ongoing Mars Surveyor missions.

Gulick, V. C.↗

A Detailed Investigation into the Use of Planetary Nebulae as Standard Candles

The program's goal was to understand the physics underlying the [O III] (lambda)5007 planetary nebula luminosity function (PNLF) and evaluate its accuracy as an extragalactic distance indicator. Work under the grant concentrated in two areas. The first major goal was to extensively test the PNLF method to find its limits. We did this performing yet another internal test of the method in the core galaxies of the Fornax Cluster, performing external comparisons of PNLF distances with distances derived from Cepheids and the Surface Brightness Fluctuation method (SBF), and, in general, examining the PNLF in as many different galactic environments as possible, including the disks of late-type spirals. Because of the difficulty distinguishing planetary nebulae (PNe) from H II regions, and because spiral galaxies have uneven internal extinction, the process of identifying "statistical" samples of PNe in these objects is extremely complicated. Nevertheless, by using the ratio of [O III] (lambda)5007 to H(alpha) as a diagnostic, we were able to effectively discriminate PNe from most H II regions, and apply the method to systems such as NGC 300, M101, M51, and M96. The second goal of this research was to determine theoretically, why the PNLF is such an excellent standard candle.

Ciardullo, Robin↗

Curiosity: the Mars Science Laboratory Project

The Curiosity rover landed successfully in Gale Crater, Mars on August 5, 2012. This event was a dramatic high point in the decade long effort to design, build, test and fly the most sophisticated scientific vehicle ever sent to Mars. The real achievements of the mission have only just begun, however, as Curiosity is now searching for signs that Mars once possessed habitable environments. The Mars Science Laboratory Project has been one of the most ambitious and challenging planetary projects that NASA has undertaken. It started in the successful aftermath of the 2003 Mars Exploration Rover project and was designed to take significant steps forward in both engineering and scientific capabilities. This included a new landing system capable of emplacing a large mobile vehicle over a wide range of potential landing sites, advanced sample acquisition and handling capabilities that can retrieve samples from both rocks and soil, and a high reliability avionics suite that is designed to permit long duration surface operations. It also includes a set of ten sophisticated scientific instruments that will investigate both the geological context of the landing site plus analyze samples to understand the chemical & organic composition of rocks & soil found there. The Gale Crater site has been specifically selected as a promising location where ancient habitable environments may have existed and for which evidence may be preserved. Curiosity will spend a minimum of one Mars year (about two Earth years) looking for this evidence. This paper will report on the progress of the mission over the first few months of surface operations, plus look retrospectively at lessons learned during both the development and cruise operations phase of the mission..

project formulation↗

Overview of Recent EAST Testing, Modeling & Analysis

Shock Layer Radiation at NASA Ames - Background: Complex aerothermal and thermochemical phenomena of planetary entry define convective and radiative heating. A spacecraft's TPS (Thermal Protective System) mitigates heat transfer to substructure. Successful TPS design relies on verifiable characterization of these phenomena in the anticipated flight environment. - Approach: EAST (Electric Arc Shock Tube) [facility at Ames] simulates high-enthalpy, real-gas phenomena encountered by hypersonic vehicles entering planetary atmospheres by spectrally imaging the flow behind a moving shock wave. - Goal: Validate aerothermal models (DPLR (Data Parallel Line Relaxation Code) and NEQAIR (Nonequilibrium Radiative Transport and Spectra Program)), inform model improvements, reduce uncertainty and quantify design uncertainties. - Recent Relevant Projects: MSL (Mars Science Laboratory) & Mars 2020, InSight, OSIRIS-REx (Origins Spectral Interpretation Resource Identification Security Regolith Explorer), Orion EFT-1 (Exploration Flight-1) and EM-1 (Exploration Mission-1) and New Frontiers.

Brandis, Aaron↗

Containerless high-pressure petrology experiments in the microgravity environment of the Space Station

The genesis of igneous rocks on terrestrial planets can only be understood through experiments at pressures corresponding to those in planetary mantles (10 to 50 kbar). Such experiments typically require a piston-cylinder apparatus, and an apparatus that has the advantage of controllable pressure and temperature, adequate sample volume, rapid sample quench, and minimal danger of catastrophic failure. It is proposed to perform high-pressure and high-temperature piston-cylinder experiments aboard the Space Station. The microgravity environment in the Space Station will minimize settling due to density contrasts and may, thus, allow experiments of moderate duration to be performed without a platinoid capsule and without the sample having to touch the container walls. The ideal pressure medium would have the same temperatures. It is emphasized, however, that this proposed experimental capability requires technological advances and innovations not currently available.

Boynton, W. V.↗

1991 NASA Planetary Rover Program

The principal accomplishments of the 1991 Nasa Planetary Rover Program are described. The work to date has focused on development of unmanned science rover technology within the context of high mobility wheeled vehicles at the JPL and an innovative legged locomotion concept at Carnegie Mellon University. Attention is given to mission operations research including simulation environment, mission scenario simulation experiments, and the rover system executive software that will reside onboard a rover in future planetary surface missions.

Lavery, David↗

Lessons from Astrobiological Planetary Analogue Exploration in Iceland: Biomarker Assay Performance and Downselection

Understanding the sensitivity of biomarker assays to the local physicochemical environment, and the underlying spatial distribution of the target biomarkers in 'homogeneous' environments, can increase mission science return. We have conducted four expeditions to Icelandic Mars analogue sites in which an increasingly refined battery of physicochemical measurements and biomarker assays were performed, staggered with scouting of further sites. Completed expeditions took place in 2012 (location scouting and field assay use testing), 2013 (sampling of two major sites with three assays and observational physicochemical measurements), 2015 (repeat sampling of prior sites and one new site, scouting of new sites, three assays and three instruments), and 2016 (preliminary sampling of new sites with analysis of returned samples). Target sites were geologically recent basaltic lava flows, and sample loci were arranged in hierarchically nested grids at 10 cm, 1 m, 10 m, 100 m, and >1 km order scales, subject to field constraints. Assays were intended to represent a diversity of potential biomarker types (cell counting via nucleic acid staining and fluorescence microscopy, ATP quantification via luciferase luminescence, and relative DNA quantification with simple domain-level primers) rather a specific mission science target, and were selected to reduce laboratory overhead, require limited consumables, and allow rapid turnaround. All analytical work was performed in situ or in a field laboratory within a day's travel of the field sites unless otherwise noted. We have demonstrated the feasibility of performing ATP quantification and qPCR analysis in a field-based laboratory with single-day turnaround. The ATP assay was generally robust and reliable and required minimal field equipment and training to produce a large amount of useful data. DNA was successfully extracted from all samples, but the serial-batch nature of qPCR significantly limited the number of primers (hence classifications) and replicates that could be run in a single day. Fluorescence microscopy did not prove feasible under the same constraints, primarily due to the large number of person-hours required to view, analyze, and record results from the images; however, this could be mitigated with higher-quality imaging instruments and appropriate image analysis software.

Planetary↗

Field Experiments using Telepresence and Virtual Reality to Control Remote Vehicles: Application to Mars Rover Missions

This paper will describe a series of field experiments to develop and demonstrate file use of Telepresence and Virtual Reality systems for controlling rover vehicles on planetary surfaces. In 1993, NASA Ames deployed a Telepresence-Controlled Remotely Operated underwater Vehicle (TROV) into an ice-covered sea environment in Antarctica. The goal of the mission was to perform scientific exploration of an unknown environment using a remote vehicle with telepresence and virtual reality as a user interface. The vehicle was operated both locally, from above a dive hole in the ice through which it was launched, and remotely over a satellite communications link from a control room at NASA's Ames Research center, for over two months. Remote control used a bidirectional Internet link to the vehicle control computer. The operator viewed live stereo video from the TROV along with a computer-gene rated graphic representation of the underwater terrain showing file vehicle state and other related information. Tile actual vehicle could be driven either from within the virtual environment or through a telepresence interface. In March 1994, a second field experiment was performed in which [lie remote control system developed for the Antarctic TROV mission was used to control the Russian Marsokhod Rover, an advanced planetary surface rover intended for launch in 1998. Marsokhod consists of a 6-wheel chassis and is capable of traversing several kilometers of terrain each day, The rover can be controlled remotely, but is also capable of performing autonomous traverses. The rover was outfitted with a manipulator arm capable of deploying a small instrument, collecting soil samples, etc. The Marsokhod rover was deployed at Amboy Crater in the Mojave desert, a Mars analog site, and controlled remotely from Los Angeles. in two operating modes: (1) a Mars rover mission simulation with long time delay and (2) a Lunar rover mission simulation with live action video. A team of planetary geologists participated in the mission simulation. The scientific goal of the science mission was to determine what could be learned about the geologic context of the site using the capabilities of imaging and mobility provided by the Marsokhod system in these two modes of operation. I will discuss the lessons learned from these experiments in terms of the strategy for performing Mars surface exploration using rovers. This research is supported by the Solar System Exploration Exobiology, Geology, and Advanced Technology programs.

Stoker, Carol↗