233 research outputs found

    Application of Risk Informed Decision Making to Highly Reliable Three Dimensionally Woven Thermal Protection System for Mars Sample Return

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    The NASA Risk Informed Decision Making process is used to assess a trade space of three dimensionally woven thermal protection systems for application to the Mars Sample Return Earth Entry Vehicle. Candidate architectures are assessed based on mission assurance, technical development, cost, and schedule risk. Assessment methodology differed between the architectures, utilizing a four-point quantitative scale for mission assurance and technical development and highly tailored PERT techniques for cost and schedule. Risk results are presented, in addition to a review of RIDM effectiveness for this application

    Variation in fast-start performance within a population of polyphenic bluegill (Lepomis macrochirus)

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    Bluegill sunfish Lepomis macrochirus exhibit intraspecific variation in their morphology and swimming performance based on habitat. The pelagic form has a relatively streamlined, fusiform body shape associated with greater steady-state swimming speed and energy economy. In contrast, littoral bluegill have deeper bodies with fins located farther from their center of mass to enhance maneuverability among littoral vegetation. Deeper body shapes have been associated with increased faststart performance to escape predators or capture prey. We hypothesized that littoral bluegill, which have a deeper body shape, would exhibit greater fast-start performance than pelagic bluegill. A total of 29 bluegill (16 littoral, 13 pelagic) were caught by hook and line, and their fast-start performance was analyzed from high-speed video recordings. Body shape appears to be a poor predictor of fast-start performance. Contrary to our expectations, pelagic bluegill had a significantly higher peak velocity, peak acceleration, and angular velocity compared to littoral bluegill. Pelagic bluegill living among larger predators and foraging on mobile prey may be exposed to selection pressures that favor increased fast-start performance. Integrated studies of internal morphology and physiology are needed to fully understand the relationship between morphology and performance in this population

    Enabling Entry Technologies for Ice Giant Missions

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    The highest priority science goals for Ice Giant missions are: 1) Interior structure of the Planet, and 2) Bulk composition that includes isotopes and noble gases. The interaction between the planetary interior and the atmosphere requires sustained global measurements. Noble gas and Isotope measurements require in situ measurement. Drag modulated aerocapture utilizing ADEPT offers more mass delivered to the Ice Giants than with propulsive orbit insertion. The Galileo Probe entered at a hot spot which created interpretation challenges. Juno is providing valuable orbital measurements, but without in situ measurements the story is incomplete. Planetary scientists interested in Ice Giant missions should perform mission design studies with these new Entry System technologies to assess the feasibility within the context of the international collaboration framework. A mission architecture that includes probe(s) along with an orbiting spacecraft can deploy the probes at the desired location while taking simultaneous measurements from orbit to provide invaluable data that can correlate both global and local measurements. Entry System Technologies currently being developed by NASA are poised to enable missions that position the Orbiter & Probes through drag modulated aerocapture (ADEPT), and HEEET enables the Probes to survive the extreme environments encountered for entry into the atmospheric interior

    Application of Risk Informed Decision Making to a Highly Reliable Three-Dimensionally Woven Thermal Protection System for Mars Sample Return

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    The NASA Risk Informed Decision Making process is used to assess a trade space of three dimensionally woven thermal protection systems for application to the Mars Sample Return Earth Entry Vehicle. Candidate architectures are assessed based on mission assurance, technical development, cost, and schedule risk. Assessment methodology differed between the architectures, utilizing a four-point quantitative scale for mission assurance and technical development and highly tailored PERT techniques for cost and schedule. Risk results are presented, in addition to a review of RIDM effectiveness for this application

    White Papers for the Next Decadal Survey: Thermal Protection Systems and Instrumentation

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    NASA is anticipated to commission the next Planetary Science Decadal Survey (PSDS) with preparation expected in early calendar year 2020. The new PSDS will outline the priorities of science missions for the decade spanning 2023-2032. For the previous PSDS, the science and technology communities have been invited to submit white papers to the PSDS sub-panels as background information to guide the PSDS recommendations. The National Research Council has previously stated that white papers that represent the opinion of many authors from different institutions carried more significant and weight, and the recommendations from the previous PSDS attempted to reflect more of a consensus opinion.In 2009, a total of 4 white papers were submitted to the PSDS panels regarding thermal protection system (TPS) readiness for missions, as well as one on TPS instrumentation. The TPS readiness papers were co-authored by 90 individuals from many institutions. These white papers surveyed the TPS materials for both forebody and afterbody of a probe and analyzed the suitability of materials for missions to each destination. In addition, each paper outlined the ground testing required and ongoing technology development. Recommendations were provided for further technology development and ground test capability in order to fulfill future missions. Planning for the next PSDS: Many improvements and changes have occurred in the past 10 years with regard to TPS materials and instrumentation. New materials have been developed and tested, such as the high density material Heatshield for Extreme Entry Environment Technology (HEEET), and new capabilities for ground testing for high heating and high pressures have been added such as the 3 nozzle at the Ames arc jet. NASA has also flown several TPS instrumentation suites, such as MEDLI and EFT-1.In order to provide the PSDS sub-panels with the most current information about the state-of-the-art suit-ability for TPS materials for entry missions, we are be-ginning to update and draft new white papers. We will present the outline for material to be covered in the white papers, and we invite all IPPW attendees to parti-ciate in co-authoring these papers

    Heatshield for Extreme Entry Environment Technology (HEEET) for Missions to Saturn and Beyond

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    This poster provides an overview of the requirements, design, development and testing of the 3D Woven TPS being developed under NASAs Heatshield for Extreme Entry Environment Technology (HEEET) project. Under this current program, NASA is working to develop a Thermal Protection System (TPS) capable of surviving entry into Saturn. A primary goal of the project is to build and test an Engineering Test Unit (ETU) to establish a Technical Readiness Level (TRL) of 6 for this technology by 2017

    Heatshield for Extreme Entry Environment Technology (HEEET) TPS for Ice Giants Probe Missions

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    This poster provides an overview of the requirements, design, development and testing of the 3D Woven TPS being developed under NASAs Heatshield for Extreme Entry Environment Technology (HEEET) project. Under this current program, NASA is working to develop a Thermal Protection System (TPS) capable of surviving entry into Saturn. A primary goal of the project is to build and test an Engineering Test Unit (ETU) to establish a Technical Readiness Level (TRL) of 6 for this technology by 2018. Poster also discusses use of HEEET TPS for probe missions to the Ice Giants, Uranus and Neptune
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