2,343 research outputs found

    Ablative shielding for hypervelocity projectiles

    Get PDF
    A hypervelocity projectile shield which includes a hollow semi-flexible housing fabricated from a plastic like, or otherwise transparent membrane which is filled with a fluid (gas or liquid) is presented. The housing has a inlet valve, similar to that on a tire or basketball, to introduce an ablating fluid into the housing. The housing is attached by a Velcro mount or double-sided adhesive tape to the outside surface of a structure to be protected. The housings are arrayed in a side-by-side relationship for complete coverage of the surface to be protected. In use, when a hypervelocity projectile penetrates the outer wall of a housing it is broken up and then the projectile is ablated as it travels through the fluid, much like a meteorite 'burns up' as it enters the earth's atmosphere, and the housing is deflated. The deflated housing can be easily spotted for replacement, even from a distance. Replacement is then accomplished by simply pulling a deflated housing off the structure and installing a new housing

    High-pressure promoted combustion chamber

    Get PDF
    In the preferred embodiment of the promoted combusiton chamber disclosed herein, a thick-walled tubular body that is capable of withstanding extreme pressures is arranged with removable upper and lower end closures to provide access to the chamber for dependently supporting a test sample of a material being evaluated in the chamber. To facilitate the real-time analysis of a test sample, several pressure-tight viewing ports capable of withstanding the simulated environmental conditions are arranged in the walls of the tubular body for observing the test sample during the course of the test. A replaceable heat-resistant tubular member and replaceable flame-resistant internal liners are arranged to be fitted inside of the chamber for protecting the interior wall surfaces of the combustion chamber during the evaluation tests. Inlet and outlet ports are provided for admitting high-pressure gases into the chamber as needed for performing dynamic analyses of the test sample during the course of an evaluation test

    Southern California partyboat angler survey

    Get PDF
    Previous studies suggest that ocean anglers are unable to identify many common marine fishes and that they frequently use nondesignated common names for those fishes with which they are familiar. This paper discusses the ability of the anglers and crew aboard commercial passenger fishing vessels (CPFV) to identify 22 fishes caught off southern California and relates this ability to fishing experience and frequency. Implications to resource management are also discussed. Most CPFV anglers were inexperienced and could identify only a few of the species. However, as experience increased, the scores improved. Vessel crew members scored higher than the most experienced anglers. The inability of anglers to identify marine fishes and the widespread use of nondesignated and often confusing common names help to explain why some fishery management regulations of the California Department of Fish and Game are relatively ineffective. (37pp.

    Altair

    Get PDF
    This slide presentation explores some of the issues that concern the engineers and planners of the Altair Lunar landing module. Particular attention is paid to the issues concerning Lunar dust, and attempts that will be made to test the Altair systems using Lunar dust simulants

    Standardized Tests: Effects on Science Education and Diversity in Science

    Get PDF
    Standardized tests are ubiquitous in the American educational system. The excessive use of standardized tests has led to a decrease in taught content and has pushed teachers at the high school level to adopt less effective teaching styles that are also extremely common for introductory STEM courses at the undergraduate level. The heavy reliance on ACT and SAT scores for acceptance into college is misplaced, as the ACT/SAT are poor predictors of STEM college graduation. Also, underrepresented students (women, racial minorities, and lower socioeconomic groups) are disproportionately impacted by the heavy use of standardized tests. These students tend to score lower on the ACT/SAT, which makes it more difficult for them to get into higher education and may also make them feel unqualified to obtain a STEM degree. Therefore, adopting a more engaging style of teaching and dropping test requirements, both of which can increase diversity in STEM, could ameliorate the issues that arise from standardized tests and better prepare students for their next steps in STEM. An effective science education, one that focuses on student engagement, is more important than standardized test scores in providing all students with an equal opportunity to succeed

    Strategic Implications of Phobos as a Staging Point for Mars Surface Missions

    Get PDF
    As human exploration endeavors begin to set sights beyond low Earth orbit to the surface of the Moon, exploration of the surface of Mars continues to serve as the horizon destination to help focus development and research efforts. One Mars exploration strategy often discussed is the notion of utilizing the moons of Mars, namely Phobos, as an exploration destination prior to Mars surface missions. The premise behind this is that staging missions from Mars moons as well as exploring the moons themselves would be less costly and risky. However, understanding potential advantages of Phobos staging and exploration must be done in the context of the overall end-to-end Mars surface exploration needs, goals, objectives, campaign approach, and systems required. This paper examines the strategic implications of utilizing the moons of Mars as a potential location for exploration of Mars. Operational concepts utilizing both Phobos and Mars orbital strategies will be examined to understand the architectural impacts of this staging strategy. The strategic implications of each operational concept are assessed to determine the overall key challenges and strategic links to other exploration destinations. Results from this analysis indicate that, if the objective is to conduct Mars surface missions, utilizing Phobos as an exploration destination adds little benefit toward the goal of exploration of Mars

    Integrated Surface Power Strategy for Mars

    Get PDF
    No abstract availabl

    Mars Surface Tunnel Element Concept

    Get PDF
    How crews get into or out of their ascent vehicle has profound implications for Mars surface architecture. Extravehicular Activity (EVA) hatches and Airlocks have the benefit of relatively low mass and high Technology Readiness Level (TRL), but waste consumables with a volume depressurization for every ingress/egress. Perhaps the biggest drawback to EVA hatches or Airlocks is that they make it difficult to keep Martian dust from being tracked back into the ascent vehicle, in violation of planetary protection protocols. Suit ports offer the promise of dust mitigation by keeping dusty suits outside the cabin, but require significant cabin real estate, are relatively high mass, and current operational concepts still require an EVA hatch to get the suits outside for the first EVA, and back inside after the final EVA. This is primarily because current designs don't provide enough structural support to protect the suits from ascent/descent loads or potential thruster plume impingement. For architectures involving more than one surface element-such as an ascent vehicle and a rover or surface habitat-a retractable tunnel is an attractive option. By pushing spacesuit don/doff and EVA operations to an element that remains on the surface, ascended vehicle mass and dust can be minimized. What's more, retractable tunnels provide operational flexibility by allowing surface assets to be re-configured or built up over time. Retractable tunnel functional requirements and design concepts being developed as part of the National Aeronautics and Space Administration's (NASA) Evolvable Mars Campaign (EMC) work will add a new ingress/egress option to the surface architecture trade space

    Center Innovation Fund: JSC CIF Characterize Human Forward Contamination

    Get PDF
    Let's face it: wherever we go, we will inevitably carry along the little critters that live in and on us. Conventional wisdom has long held that it's unlikely those critters could survive the space environment, but in 2007 microscopic animals called Tardigrades survived exposure to space and in 2008 Cyanobacteria lived for 548 days outside the International Space Station (ISS). But what about the organisms we might reasonably expect a crewed spacecraft to leak or vent? Do we even know what they are? How long might our tiny hitch-hikers survive in close proximity to a warm spacecraft that periodically leaks/vents water or oxygen-and how might they mutate with long-duration exposure? Unlike the Mars rovers that we cleaned once and sent on their way, crew members will provide a constantly regenerating contaminant source. Are we prepared to certify that we can meet forward contamination protocols as we search for life at new destinations
    corecore