Keywords: ISS, Space Station, ARIS, microgravity, umbilicals, planar elastica
Abstract: The International Space Station relies on the active rack isolation system (ARIS) as the central component of an integrated, station-wide strategy to isolate microgravity space-science experiments. ARIS uses electromechanical actuators to isolate an international standard payload rack from disturbances due to the motion of the Space Station. Disturbances to microgravity experiments on ARIS-isolated racks are transmitted primarily via the ARIS power and vacuum umbilicals. Experimental tests indicate that these umbilicals resonate at frequencies outside the ARIS controller’s bandwidth at levels of potential concern for certain microgravity experiments. Reduction in the umbilical resonant frequencies could help to address this issue. This work documents the development and verification of equations for the in-plane deflections and flexibilities of an idealized umbilical (thin, flexible, inextensible, cantilever beam) under end-point, in-plane loading (inclined-force and moment). The effect of gravity is neglected due to the on-orbit application. The analysis assumes an initially curved (not necessarily circular), cantilevered umbilical with uniform cross-section, which undergoes large deflections with no plastic deformation, such that the umbilical slope changes monotonically. The treatment is applicable to the ARIS power and vacuum umbilicals under the indicated assumptions.
Keywords: TOCA, water recovery system, Space Station, potable water supply, RFI
Abstract: This report summarizes the review and analysis of the proposed solutions submitted to meet the water quality monitoring requirements. Proposals were to improve upon the functionality of the existing Space Station Total Organic Carbon Analyzer (TOCA) and monitor additional contaminants in water samples. The TOCA is responsible for in-flight measurement of total organic carbon, total inorganic carbon, total carbon, pH, and conductivity in the Space Station potable water supplies. The current TOCA requires hazardous reagents to accomplish the carbon analyses. NASA is using the request for information process to investigate new technologies that may improve upon existing capabilities, as well as reduce or eliminate the need for hazardous reagents. Ideally, a replacement for the TOCA would be deployed in conjunction with the delivery of the Node 3 water recovery system currently scheduled for November 2007.
Keywords: bioastronautics, aerospace environments, critical path method, research, resource allocation
Abstract: The Bioastronautics Critical Path Roadmap is the framework used to identify and assess the risks to crews exposed to the hazardous environments of space. It guides the implementation of research strategies to prevent or reduce those risks. Although the BCPR identifies steps that must be taken to reduce the risks to health and performance that are associated with human space flight, the BCPR is not a “critical path” analysis in the strict engineering sense. The BCPR will evolve to accommodate new information and technology development and will enable NASA to conduct a formal critical path analysis in the future. As a management tool, the BCPR provides information for making informed decisions about research priorities and resource allocation. The outcome-driven nature of the BCPR makes it amenable for assessing the focus, progress and success of the Bioastronautics research and technology program. The BCPR is also a tool for communicating program priorities and progress to the research community and NASA management.
Keywords: arc jet engines, atmospheric entry, structural analysis, tiles, silicon rectifiers, spacecraft maintenance, emissivity, thermal stability, shrinkage.
Abstract: Arc jet tests of candidate tile repair materials and baseline Orbiter uncoated reusable surface insulation (RSI) were performed in the Johnson Space Center’s (JSC) Atmospheric Reentry Materials and Structures Evaluation Facility (ARMSEF) from June 23, 2003, through August 19, 2003. These tests were performed to screen candidate tile repair materials by verifying the high temperature performance and determining the thermal stability. In addition, tests to determine the surface emissivity at high temperatures and the geometric shrinkage of bare RSI were performed. In addition, tests were performed to determine the surface emissivity at high temperatures and the geometric shrinkage of uncoated RSI.arc
Keywords: manned spacecraft, space suits, pressure suits, atmospheres, controlled atmospheres, life support systems.
Abstract: The selection of spacecraft and space suit atmospheres for future human space exploration missions will play an important, if not critical, role in the ultimate safety, productivity, and cost of such missions. Internal atmosphere pressure and composition (particularly oxygen concentration) influence many aspects of spacecraft and space suit design, operation, and technology development. Optimal atmosphere solutions must be determined by iterative process involving research, design, development, testing, and systems analysis. A necessary first step in this process is the establishment of working bounds on the atmosphere design space.
Keywords: Weightlessness, weightlessness simulation, parabolic flight, zero gravity, aerospace medicine, astronaut performance, bioprocessing, space manufacturing.
Abstract: This document represents a summary of medical and scientific evaluations conducted aboard the KC-135 from June 23, 2004 to June 27, 2005. Included is a general overview of KC-135 activities manifested and coordinated by the Human Adaptation and Countermeasures Office. A collection of brief reports that describe tests conducted aboard the KC-135 follows the overview. Principal investigators and test engineers contributed significantly to the content of the report describing their particular experiment or hardware evaluation. This document concludes with an appendix that providesbackground information concerning the KC-135 and the Reduced-Gravity Program.
Keywords: cognition; exploration, space flight; risk; management, human resources; responses, physiological; sensory perception; perception; human performance
Abstract: "Cognition in Space Workshop I: Metrics and Models" was the first in a series of workshops sponsored by NASA to develop an integrated research and development plan supporting human cognition in space exploration. The workshop was held in Chandler, Arizona, October 25–27, 2004. The participants represented academia, government agencies, and medical centers. This workshop addressed the following goal of the NASA Human System Integration Program for Exploration: to develop a program to manage risks due to human performance and human error, specifically ones tied to cognition. Risks range from catastrophic error to degradation of efficiency and failure to accomplish mission goals. Cognition itself includes memory, decision making, initiation of motor responses, sensation, and perception. Four subgoals were also defined at the workshop as follows: (1) NASA needs to develop a human-centered design process that incorporates standards for human cognition, human performance, and assessment of human interfaces; (2) NASA needs to identify and assess factors that increase risks associated with cognition; (3) NASA needs to predict risks associated with cognition; and (4) NASA needs to mitigate risk, both prior to actual missions and in real time. This report develops the material relating to these four subgoals.
Keywords: probability distribution functions; galactic cosmic rays; solar radiation; morality; radiation effects; radiation shielding; radiation; cancer; mission planning
Abstract: This document addresses calculations of probability distribution functions (PDFs) representing uncertainties in projecting fatal cancer risk from galactic cosmic rays (GCR) and solar particle events (SPEs). PDFs are used to test the effectiveness of potential radiation shielding approaches. Monte-Carlo techniques are used to propagate uncertainties in risk coefficients determined from epidemiology data, dose and dose-rate reduction factors, quality factors, and physics models of radiation environments. Competing mortality risks and functional correlations in radiation quality factor uncertainties are treated in the calculations. The cancer risk uncertainty is about four-fold for lunar and Mars mission risk projections. For short-stay lunar missins (<180 d), SPEs present the most significant risk, but one effectively mitigated by shielding. For long-duration (>180 d) lunar or Mars missions, GCR risks may exceed radiation risk limits. While shielding materials are marginally effective in reducing GCR cancer risks because of the penetrating nature of GCR and secondary radiation produced in tissue by relativisitc particles, polyethylene or carbon composite shielding cannot be shown to significantly reduce risk compared to aluminum shielding. Therefore, improving our knowledge of space radiobiology to narrow uncertainties that lead to wide PDFs is the best approach to ensure radiation protection goals are met for space exploration.
Keywords: space debris; miss distance; predictions; forecasting; energy dissipation; shielding; collision avoidance; radar cross sections; inclination, orbits; circular orbits
Abstract: A responsibility of the Trajectory Operations Officer is to ensure that the International Space Station (ISS) avoids colliding with debris. United States Space Command (USSPACECOM) tracks and catalogs a portion of the debris in Earth orbit, but only objects with a perigee less than 600 km and a radar cross section (RCS) greater than 10 cm—objects that, in fact, represent only a small fraction of the objects in Earth orbit. To accommodate for this, the ISS uses shielding to protect against collisions with smaller objects. This study provides a better understanding of how quickly, and to what degree, USSPACECOM projections tend to converge to the final, true miss distance. The information included is formulated to better predict the behavior of miss distance data during real-time operations. It was determined that the driving components, in order of impact on miss distance fluctuations, are energy dissipation rate (EDR), RCS, and inclination. Data used in this analysis, calculations made, and conclusions drawn are stored in Microsoft Excel log sheets. A separate log sheet, created for each conjunction, contains information such as predicted miss distances, apogee and perigee of debris orbit, EDR, RCS, inclination, tracks and observations, statistical data, and other evaluation/orbital parameters.
Keywords: Human performance, abilities; life support systems; systems engineering; Medical science, cardiology; aerospace medicine; communication; exploration
Abstract: The 2004 Johnson Space Center (JSC) National Aeronautics and Space Administration Faculty Fellowship Program (NFFP) was conducted by Texas A&M University and JSC. The program was funded by the Office of Education, NASA Headquarters, Washington, D.C. and by JSC. Each faculty Fellow spent at least 10 weeks at JSC (or the White Sands Test Facility) engaged in a research project in collaboration with a NASA/JSC colleague. This document is a compilation of the final reports on the research projects done by the Fellows during the summer of 2004. Volume 1 contains reports 1 through 12 and Volume 2 contains reports 13 through 22.
Keywords: Aerospace medicine, radiation, gravitational physiology, space psychlogy, weightliessness, biomedical data.
Abstract: The paper describes what we have learned from the first four years of research on ISS relative to the exploration mission, the on-going research being conducted in this regard, and our current understanding of the major exploration mission risks that the ISS can be used to address. Specifically, we discuss research carried out on the ISS to determine the mechanisms by which human health is affected on long-duration exploration missions. We also discuss how targeted technological developments can enable mission design trade studies. We discuss the relationship between the ultimate number of human test subjects available on the ISS to the quality and quantity of results of NASA's efforts over the past year to realign the ISS research programs to support a product-driven portfolio that is directed towards reducing the major risks of exploration.
Keywords: Weightlessness, astronaut performance, bone demineralization,
Abstract: Prolonged exposure to weightlessness associated with spaceflight provokes profound physiological changes in humans. Two areas of significant concern are bone loss and neuromuscular deconditioning. Changes in lower-limb neuromuscular activation patterns have raised concern about the ability of astronauts to escape from their spacecraft in an emergency landing situation. Countermeasures that stimulate bone maintenance and locomotor control are vital to the success of human spaceflight. It has been hypothesized that, to help maintain the bone mineral density that an astronaut has in normal gravity, the ground reaction force (GRF) achieved during locomotion in weightlessness should mimic the GRF that occurs on Earth. Currently, a crewmember exercising on the treadmill recieves an external load by means of an upper-body harness that attaches to the SLD via extender straps or bungees. GRF is imparted as the SLD pulls the crewmember toward the treadmill surface during locomotion. The primary objective of this investigation was to determine if gait, GRF, an kinematics during locomotion at 0G, using a simulated ISS treadmill and SLD, are significantly different from those found during locomotion at 1G. The secondary objective of this investigation was to quantify the load magnitude, variability, and stiffness of the external load applied to the crewmember by the SLD during locomotion at -G.
Keywords: International Space Station, Space Shuttle, knowledge capture, knowledge management, human space vehicles
Abstract: The incorporation of knowledge capture and knowledge management strategies early in the development phase of an exploration program is necessary for safe and successful missions of human and robotic exploration vehicles of the life of a program. Following the transition from the development to the flight phase, loss of underlying theory and rationale governing design and requirements occur through a number of mechanisms. This degrades the quality of engineering work resulting in increased life cycle costs and risk to mission success and safety of flight.Application of advanced information technology to perform knowledge capture and management would be most effective if program-wide requirements are defined at the beginning of a program.
Keywords: satellite breakup, human tended vehicles, SBRAM, shuttle, satellite
Abstract: There have been 30 known satellite breakups from First Element Launch in November 1998 to June 2005. While breakups have been studied, the threat they cause to human space flight is not well understood. Previous studies simply assessed the probability of collision per square meter and never considered different particle diameters or vulnerable areas of vehicles. Also, no flight rules exist to aid the crew and flight control team in response to a satellite breakup, causing concern for the safety of crew members and vehicles. This study fills the gaps left by previous tests and provides information that will be used to create flight rules that will increase safety during human spaceflight.
Keywords: International Space Station, Space Shuttle, lessons learned, X-38
Abstract: This document is a collection of writings concerning the application of GPS technology to the International Space Station, Space Station, and X-38 vehicles. An overview of how GPS technology was applied is given for each vehicle, including rationale behind the integration architecture and rationale governing the use or non-use of GPS data during flight.
Keywords: MMRB, fluid dynamics, CFD, computational fluid dynamics, Laser Doppler
Abstract: A modification of the Modular Rotating Bioreactor concept (MMRB) as described in the June 22, 2003, patent disclosure by John Muratore, Thomas Goodwin, Tuan Troung, and Carol Evans was evaluated with respect to the fluid dynamic implications of the proposed vessel geometry. A range of jet geometries was investigated using computational fluid dynamics (CFD) to provide an initial evaluation of the use of fluid jets injected directly into the cell culture volume as a means of providing mixing of oxygen and fresh perfused media, while keeping the fluid shear levels at acceptable values. The CFD results were verified with Laser Doppler Velocimeter measurements on a working model of the MMRB.
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