- API data.nasa.gov | Last Updated 2020-01-29T04:28:24.000Z
<p>Axial skeletal loads coupled with muscle forces maintain bone in the spine and lower extremities during International Space Station (ISS) missions. Current exercise equipment on ISS has a mass of over 300 kg and cannot provide controlled eccentric loads equal to concentric loads. Astronauts working in pairs can act as motor and controller for low maintenance exercise equipment and provide loads with most effective higher eccentric loads on exploration missions. A ground test prototype verified the exercise frame concept. A lower mass and volume exercise frame for neutral buoyancy testing will demonstrate a configuration that minimizes exercise space requirements while effectively positioning exercisers so they do not strike or interfere with each other's range of motion. The design for this prototype will be useful for International Space Station testing and musculoskeletal health maintenance during Orion missions.</p> <p>Axial skeletal loads coupled with muscle torque forces maintain bone in microgravity. Muscles generate higher eccentric forces than concentric, and eccentric loads near maximum have proven more effective than concentric loads for bone and muscle strengthening. Exercise trainers and physical therapists routinely provide higher eccentric loads when training and rehabilitating clients and patients. The exercise equipment allows use of controlled eccentric overload and provides trunk support to reduce injury potential compared to risks with current ISS resistance exercises. Maintaining relative position of astronauts so they do not interfere with each other in a small exercise volume is achieved in the frame that utilizes a back to back inverted position uniquely possible in neutral buoyancy and in microgravity. A light weight frame securing astronauts back to back and inverted will be designed, produced, and made available for neutral buoyancy testing. Ropes will slide through conduits and guides to connect foot plates that two Neutral Buoyancy Laboratory divers or astronauts push to apply opposing forces. The ground based prototype tested in 2015 identified a need for fulcrums with adjustable positions to provide lever arms most advantageous to specific exercises and to avoid interference with joint motions. Exercises will include wide and narrow leg presses, heel raises, hip flexion, and hip extension. The frame will accommodate anthropometric ranges from 5<sup>th</sup> percentile female through 95<sup>th</sup> percentile male, with adjustable body positions within the frame. Goal for flight hardware is 5.4 kg mass. This prototype for neutral buyancy testing is anticipated to weigh about 12 kg.</p>
- API data.nasa.gov | Last Updated 2020-01-29T03:17:44.000Z
NASA's next generation of x-ray observation missions require x-ray calorimeters with superior energy resolution. Semimetallic HgTe has already proven itself as an excellent soft x-ray absorber material due to its low heat capacity. The alloy Hg0.834Cd0.166Te is predicted to also have zero energy gap at T=0 K and a heat capacity even less that that of HgTe due to: (i) a greater Debye temperature (resulting in a lower lattice heat capacity), and (ii) a smaller electron effective mass (resulting in a lower electronic heat capacity). Thus Hg0.834Cd0.166Te-based microcalorimeter arrays are expected to have an energy resolution superior to that of HgTe-based ones. We propose the growth of single crystal Hg0.834Cd0.166Te layers by molecular beam epitaxy on Si substrates. Mercury vacancies will be filled after growth to reduce the possibility of them acting as acceptors and introducing a significant electronic heat capacity. The Hg0.834Cd0.166Te layers will be characterized by x-ray diffraction to asses their structural quality and crystallinity, FTIR mapping to confirm the uniformity of their energy gaps and alloy compositions, Hall measurements to assess their electrical transport properties, etch pit density counts to determine dislocation densities, transmission electron microscopy to determine microscopic structural information, and heat capacity measurements at mK temperatures to test their promise as high energy resolution quantum calorimeters.
- API data.nasa.gov | Last Updated 2020-01-29T01:46:03.000Z
Atmospheric clouds have strong impact on the global radiative budget. Cloud's radiative properties are strongly affected by droplet size distribution and number concentration. This SBIR project will develop an innovative, compact and inexpensive droplet measurement system (DMS), which will provide in situ measurement of droplet size distribution function and droplet number concentration in clouds. The DMS will be designed to meet the demanding requirements for deployment on small unmanned aircraft systems (UAS). Phase I will demonstrate the feasibility of the proposed method and yield benchtop technology ready for transition to a UAS-compatible prototype in Phase II.
- API data.nasa.gov | Last Updated 2020-01-29T04:11:46.000Z
There are many harsh, windy environments where a persistent in situ mobile sensor network could provide valuable data to help answer outstanding questions in the planetary sciences. On Earth, a network of distributed mobile sensors capable of energy-harvesting can provide the spatial resolutions and mission durations necessary to capture the seasonal environmental characteristics of the Arctic and Antarctic in a cost-effective manner. However, it is not possible to power these sensors using solar energy in the long dark polar winters. Mars, and Saturn's moon Titan, are also environments where a distributed mobile sensor network could enhance understanding of geology and climate. Similar to the Polar Regions, solar power cannot always be relied upon on Mars or Titan but surface winds are consistent. MoBall is a mobile sensor platform that harvests wind-energy and generates self-propulsion, and it is a candidate for deployment in the above environments. A unique electromechanical apparatus uses solenoids to harvest kinetic energy of permanent magnets as they slide freely within MoBall during wind-driven motion. The same apparatus generates self-propulsion by adjusting the magnet positions via powered solenoids, manipulating the position of the center of mass, and achieving motion from rest or biased steering. Each ball is outfitted with low-mass, low-power sensors and electronics for peer-to-peer and satellite data transmission. Teams of MoBalls will be deployed cooperatively with other in situ assets, forming a distributed sensing network over a large spatial domain. The innovative merging of energy-harvesting and mobility into a single sensor platform increases network flexibility, productivity, and lifespan. The objectives of this grant include (i) To validate self-propulsion from rest and biased steering through a series of prototypes and field tests, (ii) To employ optimal control techniques that intelligently toggle between energy-harvesting and control modes while executing basic maneuvers, and (iii) To outfit MoBall with scientifically-relevant sensors and assess the total energy budget, data transmission, science gathering capability, and environmental survivability. Achievement of the above objectives will likely entail academic contributions to switched hybrid optimal control theory and nonholonomic mechanics with Lagrangian symmetries. In addition, the development of MoBall’s mechanical and electrical systems are novel engineering contributions that may be applicable to other robots and NASA assets.
- API data.nasa.gov | Last Updated 2020-01-29T04:30:01.000Z
Chemoautotrophy–which is the anchor that embeds the biosphere within geochemistry– is grounded on carbon-fixation, the transformation of C1 compounds into small organic molecules and hence into the large array of organic compounds that constitute metabolism. Carbon monoxide (CO) is the most abundant C source in the cosmic gas phase, and follows after hydrogen as the most common gas in the universe. This proposal seeks to model the evolution of metabolism for carbon fixation into early life forms and we consider utilization of CO an excellent candidate for the carbon and energy source in the first life forms. Anaerobic chemoautotrophy, the fixation of C1 compounds in the absence of light and oxygen, is widespread among deeply branching thermophilic bacteria and archaea, through five recognized pathways. In comparing C1 acquisition systems in extant life, the reductive acetyl-CoA pathway (also known as the Wood-Ljungdahl pathway) allows for growth on various carbon sources (e.g. CO, CO2, formaldehyde) and has the lowest energy requirement and minimal need for de novo protein synthesis of the characterized carbon acquisition pathways. The capacity to fix carbon monoxide and the extreme oxygen sensitivity of its key enzymes are the grounds for our hypothesis that the Wood-Ljungdahl (WL) pathway might be the original carbon fixation pathway. Despite the key role of this pathway in the global carbon cycle, knowledge of its regulation and evolution under low-energy conditions is limited. Therefore we propose to investigate the evolution of the carbon fixation strategies in the two thermophilic chemolithoautotrophs, Carboxydothermus hydrogenoformans and Thermovibrio ammonificans and their adaptations to low energy conditions. These strictly anaerobic bacteria are able to grow in pure culture on the cosmically abundant gases CO, H2 and CO2, and each could form autonomous one-species ecosystems in minimally complex growth conditions. Thus we refer to them as sentinel organisms. Both strains encode the WL pathway, however, Thermovibrio ammonificans also encodes an alternative CO2 fixation pathway, reductive tricarboxylic acid cycle (rTCA), making it an excellent model system to investigate the interplay of parallel carbon fixation strategies under energy 'famine' or 'feast' conditions. The prototype carboxydotroph Carboxydothermus hydrogenoformans can grow by utilizing CO across the microbial "feast" to "famine" range for CO, from 1.3 atm of CO down to below 2 ppmv, the limit of detection. Our strategy includes the recombinant expression of genes and gene transcripts encoding for key enzymes in the dark CO fixation pathways of the model organisms. We will exert both positive and negative selection on the WL pathway under C-limited growth conditions, to determine regulatory mechanisms and whether genomic adaptation occurs in response to selection for increased fitness in carbon limited conditions The proposed research addresses Exobiology program goals (i) determine when and in what setting life first appeared and the characteristics of the first successful living organisms; and (ii) understand the phylogeny and physiology of microorganisms, including extremophiles, whose characteristics may reflect the nature of primitive environments.
- API data.nasa.gov | Last Updated 2020-01-29T04:36:53.000Z
This project will develop the autonomous capability to intelligently select/generate practice scenarios in order to provide individually targeted crew training when needed on long-duration missions. The ROBoT simulator contains a “track-and-capture analysis” capability which analyzes crew performance on several attributes of simulated SSRMS visiting vehicle capture tasks. Using this scoring capability as a baseline, the project will implement instructional design feedback from ROBO instructors and develop algorithms and data to provide automation of the performance evaluation, and scenario selection tasks, as well as perform longer term “lesson planning” required for long-duration missions.
- API data.nasa.gov | Last Updated 2020-01-29T01:57:44.000Z
<p>Space mechanisms often present an unusual set of requirements for tribological components such as bearings. Highly corrosive, extreme temperature, dynamic loading, etc, environmental demands sometimes drive the choice of bearing design and/or material more so than the operational requirements. Frequently, no bearing material or technology exists to satisfy all of the unique requirements of a given space mechanism. The result is that one or more desired capabilities must be compromised (eg. life, power loss, speed). The vision of the proposed effort is to broaden the current capability of bearings through new materials and design practices to eliminate some of these compromises, enabling enhanced current and future mission prospects. A promising class of materials (Nickel Titanium (NiTi) alloys) have been shown to have significant potential for challenging bearing applications requiring high corrosion resistance and/or withstanding large shock loads in addition to the typical rigors of rotating machinery. The goal of this project is to demonstrate shock and corrosion resistant NiTi bearings to address limitations in current space mechanism bearing technology.</p>
- API data.nasa.gov | Last Updated 2020-01-29T04:06:50.000Z
Laser transmitters operating at a pulse repetition rate of 20 Hz to 50 Hz and with pulse energy from 30 - 50 mJ have been considered to be an enabling technology for CO2 measurement and optical communications. PolarOnyx proposes a novel approach targeting to make reliable high energy ultra large core fiber amplifier at 1.57 micron and employing our proprietary technologies in specialty fibers, spectral shaping and pulse shaping techniques. At the end of Phase 1, and simulation study will be carried out and feasibility experiment will be demonstrated in laying out the pathway towards over 30 mJ high energy. A prototype will be demonstrated at the end of Phase II.
- API data.nasa.gov | Last Updated 2020-01-29T03:31:06.000Z
Perception Robotics is developing an innovative product, the Electrostatic Gecko Gripper? (ESG Gripper), for the industrial automation market. This unique gripping solution overcomes the shortcomings of vacuum grippers by eliminating the need for a compressed air system and offering more rapid actuation, thus achieving significant cost savings and throughput improvements in customers? manufacturing processes. The ESG gripper couples an electrostatic Perception Robotics is developing an innovative product, the ?Electrostatic Gecko Gripper(ESG Gripper), for the industrial automation market. This unique gripping solution overcomes the shortcomings of vacuum grippers by eliminating the need for a compressed air system and offering more rapid actuation, thus achieving significant cost savings and throughput improvements in customers manufacturing processes. The ESG gripper couples an electrostatic adhesive with an adhesive element inspired by gecko feet. When the electrostatic and gecko adhesives work together, a positive feedback cycle is created that, depending on surface type, can be greater than the sum of its parts. As the gecko adhesive engages, it brings the electrostatic adhesive closer to the surface, thus increasing its adhesive force; in turn, the electrostatic adhesive helps engage more of the fibrillar stalks of the gecko adhesive. Previous experimental results have shown that the combination adhesive technology can provide up to 5.1x greater adhesion that an electrostatic or gecko-like adhesive alone. This body of work will result in two hardware and software deliverables for transfer to NASA: 1.A piezoelectrically driven rig to automate and normalize the post-treatment process for improving the gecko adhesive (Q3CY1) 2.An improved industrial electrostatic gecko gripper with sensing and control software for an industrial robot. This factory-ready unit will position us well for production of a flight-ready version in Phase III. (Q4CY2)
- API data.nasa.gov | Last Updated 2020-01-29T04:51:09.000Z
In the crew compartment of a spacecraft, dust that is self-generated or from other activities pose a respiratory irritant, especially within a small, confined space. Therefore air cabin filtration technologies should be improved for future spacecrafts to efficiently remove the range of particulate matter sizes (nano to micron size). It is also desirable to have the new particulate air filters that can be efficiently remove volatile organic chemicals (VOCs) and self-regenerated. This will reduce the logistics burden of carrying additional replacement filters on-board. In the proposed Phase I effort, smart fibrous filters with both particle and VOC removal capacities will be developed. The new particulate filters will be much more efficient than the current HEPA filters and also capable of self-regenerating. The Phase I effort will focus on demonstration of the 'proof of concept' that fibrous filters can filter and remove the ultrafine (<0.5 μm) particulates and destructively adsorb organic chemicals such as acetone. The technical approach will also involve regeneration of filters using a low-energy process. In the Phase II project, selective filtration membranes will be designed and modified to fit the NASA's current cabin air filtration systems.