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At least 415 records · Page 23

Measurements of the performance of multiwire proportional chambers

Data are presented that may be useful in formulating engineering specifications and test procedures for the proportional counter hodoscope to be flown as part of the High Energy Cosmic Ray Experiment on the High Energy Astronomy Observatory (HEAO), Mission A. A collection of preliminary data taken in laboratory tests of multiwire counters with an anode wire spacing of 5 mm and cathode gap spacing of 1 cm is presented. The data are from laboratory development models or counters for balloon flights and were selected to illustrate several aspects of proper and improper counter performance. Most of the data were taken from a large proportional counter hodoscope which has an active area of 0.5 by 0.5 m and 104 wires per plane.

Austin, R. W.↗

Radio astronomy

The activities of the Deep Space Network in support of radio astronomy operations during the first quarter of 1981 are reported. Results of the use of a low noise maser are presented, as well as updates in DSN support of experiments sanctioned by the Radio Astronomy Experiment Selection Panel.

Shaffer, R. D.↗

Telerobot for space station

The Flight Telerobotic Servicer (FTS), a multiple arm dexterous manipulation system, will aid in the assembly, maintenance, and servicing of the space station. Fundamental ideas and basic conceptual designs for a shuttle-based telerobot system have been produced. Recent space station studies provide additional concepts that should aid in the accomplishment of mission requirements. Currently, the FTS is in contractual source selection for a Phase B preliminary design. At the same time, design requirements are being developed through a series of robotic assessment tasks being performed at NASA and commercial installations. A number of the requirements for remote operation on the space station, necessary to supplement extravehicular activity (EVA), will be met by the FTS. Finally, technology developed for telerobotics will advance the state of the art of remote operating systems, enhance operator productivity, and prove instrumental in the evolution of an adaptive, intelligent autonomous robot.

Jenkins, Lyle M.↗

Automation of vehicle processing at Space Station Freedom

A methodology for applying the Kennedy Space Center vehicle processing experience to similar operations at Space Station Freedom is described. First, the required on-orbit processing tasks are identified. These tasks are then evaluated for automation suitability, and robotic manipulator and artificial intelligence technologies are investigated to automate selected physical and cognitive tasks. Effects on processing times, extra-vehicular activity savings, and required resources for incorporating these automation enhancements are identified. Results of the following case studies are included: Phobos Gateway Vehicle On-Orbit Assembly and Launch, Lunar Evolution Vehicle On-Orbit Refurbishment, and Mars Mission Vehicle On-Orbit Assembly and Launch.

Vargo, Rick↗

Research and technology 1995 annual report

As the NASA Center responsible for assembly, checkout, servicing, launch, recovery, and operational support of Space Transportation System elements and payloads, the John F. Kennedy Space Center is placing increasing emphasis on its advanced technology development program. This program encompasses the efforts of the Engineering Development Directorate laboratories, most of the KSC operations contractors, academia, and selected commercial industries - all working in a team effort within their own areas of expertise. This edition of the Kennedy Space Center Research and Technology 1995 Annual Report covers efforts of all these contributors to the KSC advanced technology development program, as well as technology transfer activities. Major areas of research include environmental engineering, automation, robotics, advanced software, materials science, life sciences, mechanical engineering, nondestructive evaluation, and industrial engineering.

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Human Factors Engineering as a System in the Vision for Exploration

In order to accomplish NASA's Vision for Exploration, while assuring crew safety and productivity, human performance issues must be well integrated into system design from mission conception. To that end, a two-year Technology Development Project (TDP) was funded by NASA Headquarters to develop a systematic method for including the human as a system in NASA's Vision for Exploration. The specific goals of this project are to review current Human Systems Integration (HSI) standards (i.e., industry, military, NASA) and tailor them to selected NASA Exploration activities. Once the methods are proven in the selected domains, a plan will be developed to expand the effort to a wider scope of Exploration activities. The methods will be documented for inclusion in NASA-specific documents (such as the Human Systems Integration Standards, NASA-STD-3000) to be used in future space systems. The current project builds on a previous TDP dealing with Human Factors Engineering processes. That project identified the key phases of the current NASA design lifecycle, and outlined the recommended HFE activities that should be incorporated at each phase. The project also resulted in a prototype of a webbased HFE process tool that could be used to support an ideal HFE development process at NASA. This will help to augment the limited human factors resources available by providing a web-based tool that explains the importance of human factors, teaches a recommended process, and then provides the instructions, templates and examples to carry out the process steps. The HFE activities identified by the previous TDP are being tested in situ for the current effort through support to a specific NASA Exploration activity. Currently, HFE personnel are working with systems engineering personnel to identify HSI impacts for lunar exploration by facilitating the generation of system-level Concepts of Operations (ConOps). For example, medical operations scenarios have been generated for lunar habitation in order to identify HSI requirements for the lunar communications architecture. Throughout these ConOps exercises, HFE personnel are testing various tools and methodologies that have been identified in the literature. A key part of the effort is the identification of optimal processes, methods, and tools for these early development phase activities, such as ConOps, requirements development, and early conceptual design. An overview of the activities completed thus far, as well as the tools and methods investigated will be presented.

Mihriban Whitmore↗

Manufacture of Cryoshroud Surfaces for Space Simulation Chambers

Environmental test chambers for space applications use internal shrouds to simulate temperature conditions encountered in space. Shroud temperatures may range from +150 C to -253 C (20 K), and internal surfaces are coated with special high emissivity/absorptivity paints. To obtain temperature uniformity over large areas, detailed thermal design is required for placement of tubing for gaseous or liquid nitrogen and helium and other exotic heat exchange fluids. The recent increase in space simulation activity related to the James Webb Space Telescope has led to the design of new cryogenic shrouds to meet critical needs in instrument package testing. This paper will review the design and manufacturing of shroud surfaces for several of these programs, including fabrication methods and the selection and application of paints for simulation chambers.

Ash, Gary S.↗

Historical Evolution of NASA Standard Materials Testing with Hypergolic Propellants and Ammonia (NASA Standard 6001 Test 15)

The NASA Johnson Space Center White Sands Test Facility (WSTF) has performed testing of hazardous and reactive aerospace fluids, including hypergolic propellants, with materials since the 1960s with the Apollo program. Amongst other test activities, Test 15 is a NASA standard test for evaluating the reactivity of materials with selected aerospace fluids, in particular hydrazine, monomethylhydrazine, uns-dimethylhydrazine, Aerozine 50, dinitrogen tetroxide oxidizers, and ammonia. This manuscript provides an overview of the history of Test 15 over a timeline ranging from prior to its development and first implementation as a NASA standard test in 1974 to its current refinement. Precursor documents to NASA standard tests, as they are currently known, are reviewed. A related supplementary test, international standardization, and enhancements to Test 15 are also discussed. Because WSTF was instrumental in the development and implementation of Test 15, WSTF experience and practices are referred to in this manuscript.

Greene, Benjamin↗

Analysis of Exercise Loads to Inform Vibration Isolation System Design

BACKGROUND: This study was conducted with the primary interest of providing data that would inform Vibration Isolation and Stabilization (VIS) system design and performance for the European Enhanced Exploration Exercise Device (E4D). In preparation for the International Space Station (ISS) in-flight demonstration, a list of critical Human Health Countermeasures (HHC) exercises was compiled [1]. The goal of this study was to assess the ground reaction forces and moments imposed by an exercising subject in each of the six VIS Degrees of Freedom (DOFs) during a comprehensive set of these critical exercises performed on the E4D. METHODS AND RESULTS: The ISS in-flight demonstration list of critical exercises included seated aerobic rowing, bent-over rowing, cycling, front squats, back squats, conventional deadlifts, Romanian deadlifts, heel raises, overhead presses, reverse chops, and power clean presses. At the NASA Johnson Space Center (JSC) Prototype Immersive Technology (PIT) laboratory, motion capture data were collected on critical E4D exercises for six subjects. At the NASA JSC Active Response Gravity Offload System (ARGOS) facility, additional motion capture and load cell data were collected on offloaded trials for four subjects. Select data were extrapolated to represent a 5th percentile female subject and a 95th percentile male subject. A previous investigation comparing the forces obtained from the load cell and from motion capture based data found a satisfactory level of agreement between the two measurements [2]. The motion capture based data were analyzed for this study since it is driven by the subject’s trajectory alone, automatically excluding any forces exerted on the subject by the ARGOS offloading harness. The OpenSim [3, 4] biomechanical simulation inverse kinematics tool was used to calculate the joint angles based on the locations of motion capture markers placed at key positions on the subject’s body. An OpenSim plugin was then used to obtain the forces and moments generated by the subject during each trial, with the moments computed relative to the equilibrium location of the subject’s feet [5]. The force of gravity was also removed to simulate the loads generated by the exercise when performed in microgravity. The load plots for each trial were generated and visually analyzed to obtain the magnitudes of the peak loads for each exercise in each DOF. The typical period of exercise for each trial was also estimated and used to calculate the frequency for each trial. The exercise loads data was then organized in multiple ways to capture different aspects of the data. As a result of this study, we present a summary of the load magnitudes observed during these critical exercises utilizing the E4D.

C A Bell↗

Writing the Programs of Programmable Catalysis

It has long been known that non-steady state and periodic catalytic reactor operation in terms of temperature, pressure, and composition can lead to higher overall productivity and/or product selectivity than the best steady operation. Recently, the emergence of catalysts whose intrinsic properties can be made to oscillate with time, introduces advanced forcing capabilities that can be “programmed” into the catalysts to broaden the scope and applicability of periodic operation to surface chemistry. In this work, an algorithmic approach is implemented to significantly accelerate the discovery and optimization of periodic steady states of catalytic reactors. Decomposition of complex dynamics into fundamental mechanistic fast–slow steps is seen to improve conceptual understanding of the relationship between binding energy oscillation protocols and overall catalytic rates. Finding structured forcing protocols, optimally tailored to the multiple time scales of a given individual mechanism, requires an efficient search of high-dimensional parameter spaces. Here, this is enabled here through active learning (Bayesian optimization, enhanced by our proposed Bayesian continuation). Implementation of these methods is shown to accelerate the evaluation of catalyst programs by up to several orders of magnitude. Faster screening of programmable catalysts to discover periodic steady states enables the optimization of catalytic operating protocols and thus opens the possibility for catalyst engineering based on optimal forcing programs to control rate and product selectivity, even for complex multistep catalytic mechanisms.

catalysis↗

Stiffening of the ACES deployable space boom

The purpose of this design project was to design an active planar stiffening device for the existing ACES (Acoustic Containerless Experiment System) structure. the ACES structure was modeled using simple beam theory. Various concepts were generated about how the stiffening device should be configured in order to perform at an optimum level. The optimum configuration was selected to be a single set of spreaders located approximately 63% of the distance down the beam. Actuation was to be provided by a DC electric motor. From the test results, the design group was able to draw conclusions and make recommendations about the utility of further research into this area.

Sidwell, Vince↗

Making on-orbit structural repairs to Space Station

One of the key factors dictating the safety and durability of the proposed U.S. Space Station is the ability to repair structural damage while remaining in orbit. Consequently, studies are conducted to identify the engineering problems associated with accomplishing structural repairs on orbit, due to zero gravity environment and exposure to extreme temperature variations. There are predominant forms of structural failure, depending on the metallic or composite material involved. Aluminum is the primary metallic material used in space vehicle applications. Welding processes on aluminum alloy structures were tested, resulting in final selection of electron beam welding as the primary technique for metallic material repair in Space. Several composite structure repair processes were bench-tested to define their applicability to on-orbit EVA requirements: induction heating prevailed. One of the unique problems identified as inherent in the on-orbit repair process is that of debris containment. The Maintenance Work Station concept provides means to prevent module contamination from repair debris and ensure the creation of a facility for crew members to work easily in a microgravity environment. Different technologies were also examined for application to EVA repair activities, and the concept selected was a spring-loaded, collapsible, box-like Debris Containement and Collection Device with incorporated fold-down tool boards and handholes in the front panel.

Haber, Harry S.↗

A distributed data base management system

Major system design features of a distributed data management system for the NASA Deep Space Network (DSN) designed for continuous two-way deep space communications are described. The reasons for which the distributed data base utilizing third-generation minicomputers is selected as the optimum approach for the DSN are threefold: (1) with a distributed master data base, valid data is available in real-time to support DSN management activities at each location; (2) data base integrity is the responsibility of local management; and (3) the data acquisition/distribution and processing power of a third-generation computer enables the computer to function successfully as a data handler or as an on-line process controller. The concept of the distributed data base is discussed along with the software, data base integrity, and hardware used. The data analysis/update constraint is examined.

Bryan, A. I.↗

Microgravity research at the University of Mexico: Experiments in payload G-006

The experiments contained in the G-006 payload related to thin film vapor deposition, vacuum variations in a chamber vented to space, solidification of a Zn-Al-Cu alloy, and multiple location temperature monitoring for thermal model validation are described in detail. A discussion of the expected results is presented, together with the methods selected to conduct the postflight analysis, and finally, a overview of the future activities in this field.

Peralta-Fabi, Ricardo↗

Designing the Space Transfer Vehicle (STV)

The most significant challenges facing the Space Transfer Vehicle (STV) program are making space basing affordable and developing an easily evolvable STV. Study efforts try minimizing the high cost of astronauts activities and Space Station modification to enhance affordability. Modularity, design margins, and simple interfaces are being evaluated to develop an evolutionary approach for space basing starting in the 1990's. In this STV study, the concept definition approach is presented, including concept optimization trades as well as concept selection and sensitivity analyses.

Austin, Gene↗

Application of multiple criteria decision methods in space exploration initiative design and planning

Fellowship activities were directed towards the identification of opportunities for application of the Multiple Criteria Decision Making (MCDM) techniques in the Space Exploration Initiative (SEI) domain. I identified several application possibilities and proposed demonstration application in these three areas: evaluation and ranking of SEI architectures, space mission planning and selection, and space system design. Here, only the first problem is discussed. The most meaningful result of the analysis is the wide separation between the two top ranked architectures, indicating a significant preference difference between them. It must also be noted that the final ranking reflects, to some extent, the biases of the evaluators and their understanding of the architecture.

Masud, Abu S. M.↗

Research and technology: 1994 annual report of the John F. Kennedy Space Center

As the NASA Center responsible for assembly, checkout, servicing, launch, recovery, and operational support of Space Transportation System elements and payloads, the John F. Kennedy Space Center is placing increasing emphasis on its advanced technology development program. This program encompasses the efforts of the Engineering Development Directorate laboratories, most of the KSC operations contractors, academia, and selected commercial industries - all working in a team effort within their own areas of expertise. This edition of the Kennedy Space Center Research and Technology 1994 Annual Report covers efforts of all these contributors to the KSC advanced technology development program, as well as our technology transfer activities. The Technology Programs and Commercialization Office (DE-TPO), (407) 867-3017, is responsible for publication of this report and should be contacted for any desired information regarding the advanced technology program.

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Research and Technology 1996: Innovation in Time and Space

As the NASA Center responsible for assembly, checkout, servicing, launch, recovery, and operational support of Space Transportation System elements and payloads, the John F. Kennedy Space Center is placing increasing emphasis on its advanced technology development program. This program encompasses the efforts of the Engineering Development Directorate laboratories, most of the KSC operations contractors, academia, and selected commercial industries - all working in a team effort within their own areas of expertise. This edition of the Kennedy Space Center Research and Technology 1996 Annual Report covers efforts of all these contributors to the KSC advanced technology development program, as well as our technology transfer activities.

Source record↗