1,385 research outputs found

    Skylab medical data evaluation program (SMEDEP)

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    A day-by-day summary of selected data collected during the experiment is presented. The clinical and environmental data are presented in a mission-day format along with a tabulation of biomedical measurements whose values exceed three standard deviations from the preflight measurements

    Holographic evaluation of fatigue cracks by a compressive stress (HYSTERESIS) technique

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    Holographic interferometry compares unknown field of optical waves with known one. Differences are displayed as interference bands or fringes. Technique was evaluated on fatigue-cracked 2219-T87 aluminum-alloy panels. Small cracks were detected when specimen was incrementally unloaded

    The detection of tightly closed flaws by nondestructive testing (NDT) methods

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    Liquid penetrant, ultrasonic, eddy current and X-radiographic techniques were optimized and applied to the evaluation of 2219-T87 aluminum alloy test specimens in integrally stiffened panel, and weld panel configurations. Fatigue cracks in integrally stiffened panels, lack-of-fusion in weld panels, and fatigue cracks in weld panels were the flaw types used for evaluation. A 2319 aluminum alloy weld filler rod was used for all welding to produce the test specimens. Forty seven integrally stiffened panels containing a total of 146 fatigue cracks, ninety three lack-of-penetration (LOP) specimens containing a total of 239 LOP flaws, and one-hundred seventeen welded specimens containing a total of 293 fatigue cracks were evaluated. Nondestructive test detection reliability enhancement was evaluated during separate inspection sequences in the specimens in the 'as-machined or as-welded', post etched and post proof loaded conditions. Results of the nondestructive test evaluations were compared to the actual flaw size obtained by measurement of the fracture specimens after completing all inspection sequences. Inspection data were then analyzed to provide a statistical basis for determining the flaw detection reliability

    Planetary Protection Issues in the Human Exploration of Mars

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    This workshop report, long delayed, is the first 21st century contribution to what will likely be a series of reports examining the effects of human exploration on the overall scientific study of Mars. The considerations of human-associated microbial contamination were last studied in a 1990 workshop ("Planetary Protection Issues and Future Mars Missions," NASA CP-10086, 1991), but the timing of that workshop allowed neither a careful examination of the full range of issues, nor an appreciation for the Mars that has been revealed by the Mars Global Surveyor and Mars Pathfinder missions. Future workshops will also have the advantage of Mars Odyssey, the Mars Exploration Rover missions, and ESA's Mars Express, but the Pingree Park workshop reported here had both the NCR's (1992) concern that "Missions carrying humans to Mars will contaminate the planet" and over a decade of careful study of human exploration objectives to guide them and to reconcile. A daunting challenge, and one that is not going to be simple (as the working title of this meeting, "When Ecologies Collide?" might suggest), it is clear that the planetary protection issues will have to be addressed to enable human explorers to safely and competently extend out knowledge about Mars, and its potential as a home for life whether martian or human

    Mars Sample Handling Protocol Workshop Series: Workshop 4

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    In preparation for missions to Mars that will involve the return of samples to Earth, it will be necessary to prepare for the receiving, handling, testing, distributing, and archiving of martian materials here on Earth. Previous groups and committees have studied selected aspects of sample return activities, but specific detailed protocols for the handling and testing of returned samples must still be developed. To further refine the requirements for sample hazard testing and to develop the criteria for subsequent release of sample materials from quarantine, the NASA Planetary Protection Officer convened a series of workshops in 2000-2001. The overall objective of the Workshop Series was to produce a Draft Protocol by which returned martian sample materials can be assessed for biological hazards and examined for evidence of life (extant or extinct) while safeguarding the purity of the samples from possible terrestrial contamination. This report also provides a record of the proceedings of Workshop 4, the final Workshop of the Series, which was held in Arlington, Virginia, June 5-7, 2001. During Workshop 4, the sub-groups were provided with a draft of the protocol compiled in May 2001 from the work done at prior Workshops in the Series. Then eight sub-groups were formed to discuss the following assigned topics: Review and Assess the Draft Protocol for Physical/Chemical Testing Review and Assess the Draft Protocol for Life Detection Testing Review and Assess the Draft Protocol for Biohazard Testing Environmental and Health/Monitoring and Safety Issues Requirements of the Draft Protocol for Facilities and Equipment Contingency Planning for Different Outcomes of the Draft Protocol Personnel Management Considerations in Implementation of the Draft Protocol Draft Protocol Implementation Process and Update Concepts This report provides the first complete presentation of the Draft Protocol for Mars Sample Handling to meet planetary protection needs. This Draft Protocol, which was compiled from deliberations and recommendations from earlier Workshops in the Series, represents a consensus that emerged from the discussions of all the sub-groups assembled over the course of the five Workshops of the Series. These discussions converged on a conceptual approach to sample handling, as well as on specific analytical requirements. Discussions also identified important issues requiring attention, as well as research and development needed for protocol implementation
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