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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 109 records · Page 6

Definition of experiments to investigate fire suppressants in microgravity

Defined and justified here are the conceptual design and operation of a critical set of experiments expected to yield information on suppressants and on suppressant delivery systems under realistic spacecraft-fire conditions (smoldering). Specific experiment parameters are provided on the solid fuel (carbon), oxidants (habitable spacecraft atmospheres), fuel/oxidant supply, mixing mode, and rate (quiescent and finite; ventilated and replenishable), ignition mode, event, and reignition tendency, fire-zone size, fire conditions, lifetime, and consequences (toxicity), suppressants (CO2, H2O, N2) and suppressant delivery systems, and diagnostics. Candidate suppressants were identified after an analysis of how reduced gravity alters combustion, and how these alterations may influence the modes, mechanisms, and capacities of terrestrial agents to suppress unwanted combustion, or fire. Preferred spacecraft suppression concepts included the local, near-quiescent application of a gas, vapor, or mist that has thermophysical fire-suppression activity and is chemically inert under terrestrial (normal gravity) combustion conditions. The scale, number, and duration (about 1 hour) of the proposed low-gravity experiments were estimated using data not only on the limitations imposed by spacecraft-carrier (Shuttle or Space Station Freedom) accommodations, but also data on the details and experience of standardized smolder-suppression experiments at normal gravity. Deliberately incorporated into the conceptual design was sufficient interchangeability for the prototype experimental package to fly either on Shuttle now or Freedom later. This flexibility is provided by the design concept of up to 25 modular fuel canisters within a containment vessel, which permits both integration into existing low-gravity in-space combustion experiments and simultaneous testing of separate experiments to conserve utilities and time.

Reuther, James J.↗

Active damping application to the shuttle RMS

Control Structure Interaction (CSI) is a relatively new technology developed over the last 10 to 15 years for application to large flexible space vehicles. The central issue is recognition that high performance control systems necessary for good spacecraft performance may adversely interact with the dynamics of the spacecraft structures, a problem increasingly aggravated by the large size and reduced stiffness of modern spacecraft structural designs. The CSI analysis and design methods were developed to avoid interactions while maintaining spacecraft performance without exceeding structural capabilities, but they remain largely unvalidated by hardware experiments or demonstrations, particularly in-space flight demonstrations. One recent proposal for a low cost flight validation of CSI technology is to demonstrate active damping augmentation of the Space Shuttle Remote Manipulator System (RMS). An analytical effort to define the potential for such an active damping augmentation demonstration to improve the structural dynamic response of the RMS following payload maneuvers is described. It is hoped that this study will lead to an actual inflight CSI test with the RMS using existing shuttle hardware to the maximum extent possible. By using the existing hardware, the flight demonstration results may eventually be of direct benefit to actual Space Shuttle RMS operations, especially during the construction of the Space Station Freedom.

Gilbert, Michael G.↗

Retrievable Payload Carrier (RPC): Next generation Long Duration Exposure Facility

The Retrievable Payload Carrier (RPC) is described which is a multi-experiment, free-flyer spacecraft being privately developed to make in-space experimentation more accessible and economically feasible for research and development organizations. The carrier concept was derived from NASA's highly successful and flight proven Long Duration Exposure Facility (LDEF). The LDEF capabilities were enhanced to meet new customer requirements. This reusable payload carrier is planned for launch and retrieval by the space shuttle on a regular basis. The RPC's compact design facilitates flexible manifesting of the shuttle cargo bay space, thereby, permitting timely launches and retrievals. The vehicle is designed so that either the entire carrier can be retrieved from orbit, or individual experiment pallets can be removed and replaced in orbit. This gives customers even greater control over their experiment recoveries. A fully operational RPC System consists of: (1) a carrier spacecraft; (2) a ground control station for communication with customer payloads and the carrier; (3) a ground processing facility to provide refurbishment, final checkout, and integration of customer payloads and the carrier; and (4) the personnel required to support both the development and operation phases of the program. Customer payloads will fly 6 to 18 month missions, or longer, as required. Spreading launch, operations, and retrieval costs over multiple experimental payloads results in minimized customer costs. The RPC Program's initial objective is to operate a simple carrier system which meets basic customer service needs.

Perry, Arthur T.↗

Thermal control surfaces experiment: Initial flight data analysis

The behavior of materials in the space environment continues to be a limiting technology for spacecraft and experiments. The thermal control surfaces experiment (TCSE) aboard the Long Duration Exposure Facility (LDEF) is the most comprehensive experiment flown to study the effects of the space environment on thermal control surfaces. Selected thermal control surfaces were exposed to the LDEF orbital environment and the effects of this exposure were measured. The TCSE combined in-space orbital measurements with pre and post-flight analyses of flight materials to determine the effects of long term space exposure. The TCSE experiment objective, method, and measurements are described along with the results of the initial materials analysis. The TCSE flight system and its excellent performance on the LDEF mission is described. A few operational anomalies were encountered and are discussed.

Wilkes, Donald R.↗

Technology needs of the Exploration Initiative

An overview of the U.S. Space Exploration Initiative (SEI) is presented. The two primary objectives of the initiative are a return to the moon to create a permanent lunar base and a human mission to Mars. Even though mission architectural concepts are not yet defined, previous studies indicate that the SEI will require developments in numerous areas, including advanced engines for space transportation, in-space assembly and construction to support permanent basing of exploration systems in space, and advanced surface operations capabilities including satisfactory levels of power and surface roving vehicles, and technologies to safely support human space operations of long duration. The process of mission definition has begun and it is shown that it is possible to identify a family of fundamental functional building blocks from which all SEI mission architectures will be constructed.

Aldrich, Arnold↗

Retrievable payload carrier: Next generation Long Duration Exposure Facility

This paper describes the Retrievable Payload Carrier (RPC), which is a multi-experiment, free flyer spacecraft being privately developed to make in-space experimentation more accessible and economically feasible for research and development organizations. The carrier concept was derived from NASA's highly successful and flight proven Long Duration Exposure Facility (LDEF). The LDEF capabilities have been enhanced to meet new customer requirements. This reusable payload carrier is planned for launch and retrieval by the space shuttle on a regular basis. The RPC's flexible design will facilitate manifesting of the shuttle cargo bay space. The vehicle is designed so that either the entire vehicle or only individual experiments can be removed and replaced. A fully operational RPC program consists of: (1) a carrier spacecraft; (2) a ground control station; (3) a ground processing facility; and (4) the personnel required to support both the development and operational phases of the program.

Perry, Arthur T.↗

Microgravity accelerometer characterization on Columbia STS-32 mission

The Honeywell In-Space Accelerometer (HISA) is a three-axis microgravity accelerometer instrument package recently developed by Honeywell Systems and Research Center (SRC) to monitor oscillatory and transient accelerations onboard spacecraft and spaceborne structures. The HISA was designed to be co-located with materials and life sciences experiments to record real-time accelerometer event data, sampling time, and temperature. The HISA was originally developed to monitor the microgravity disturbances associated with a polymer morphology experiment developed by 3M Company in Minneapolis, Minnesota. The HISA was first flight tested with the 3M experiment on the Space Shuttle Atlantis STS-34 in October 1989. The HISA was successfully flown on a second shuttle mission (Columbia STS-32 in January 1990) in support of the NASA JSC-sponsored Microgravity Disturbances Experiment (MDE), which focused on the effects of microgravity disturbances on the growth of high-quality Indium crystals. The primary objective of the STS-32 MDE experiment was to investigate the effects of crew-induced gravity disturbances on the microstructure (crystal defects and uniformity of impurity distribution) of float-zone-grown crystals. The float-zone technique involves establishing a suspended molten zone between two cylindrical samples a pure, single-crystal sample and an impure, polycrystalline sample. Microgravity disturbances due to crew treadmill activity and orbiter maneuvering system thruster firings were sensed and recorded by the HISA to understand their effects on the stability of the float zone. The principle of operation of the HISA, the flight configuration of the HISA supporting the MDE experiment, and the characterization of STS-32 treadmill disturbance data are summarized.

Schoess, Jeff↗

The Lidar In-Space Technology Experiment (LITE)

The primary goals of the Lidar In-Space Technology Experiment (LITE) are to demonstrate the maturity of space-based lidar technology, to provide some unique measurements, and to provide a platform for the development of technology for future space-based systems. LITE is currently scheduled to fly on the Shuttle in early 1994. Approval has recently been given for the first of several planned follow-on missions at 2-year intervals. The first mission will be used to develop experience in operating a lidar system in a space environment and to evaluate the sensitivity of the instrument for performing scientific studies. The second mission will focus on scientific studies of clouds, aerosols, and the middle atmosphere. On subsequent follow-on missions, LITE will be used as a test bed for demonstrating more advanced measurement capabilities.

Mccormick, M. Patrick↗

NASA's In-Space Technology Experiments Program - Status and plans

The Space Station Freedom constitutes a space facility uniquely suited to space technology-related R&D. Such test data as those involving fluids (power, thermal management, life support systems, and payload operations), space structures, and space materials, cannot be realistically obtained on the ground. The Space Station will also allow the validation of technologies that promise either higher performance or lower costs but which, if not validated in the necessary environment, could pose unacceptable program risks.

Harris, Leonard A.↗

Improvement in the control aspect of laser frequency stabilization for SUNLITE project

Flight Electronics Division of Langley Research Center is developing a spaceflight experiment called the Stanford University and NASA Laser In-Space Technology (SUNLITE). The objective of the project is to explore the fundamental limits on frequency stability using an FM laser locking technique on a Nd:YAG non-planar ring (free-running linewidth of 5 KHz) oscillator in the vibration free, microgravity environment of space. Compact and automated actively stabilized terahertz laser oscillators will operate in space with an expected linewidth of less than 3 Hz. To implement and verify this experiment, NASA engineers have designed and built a state of the art, space qualified high speed data acquisition system for measuring the linewidth and stability limits of a laser oscillator. In order to achieve greater stability and better performance, an active frequency control scheme requiring the use of a feedback control loop has been applied. In the summer of 1991, the application of control theory in active frequency control as a frequency stabilization technique was investigated. The results and findings were presented in 1992 at the American Control Conference in Chicago, and have been published in Conference Proceedings. The main focus was to seek further improvement in the overall performance of the system by replacing the analogue controller by a digital algorithm.

Zia, Omar↗

Modal identification experiment

The Modal Identification Experiment (MIE) is a proposed on-orbit experiment being developed by NASA's Office of Aeronautics and Space Technology wherein a series of vibration measurements would be made on various configurations of Space Station Freedom (SSF) during its on-orbit assembly phase. The experiment is to be conducted in conjunction with station reboost operations and consists of measuring the dynamic responses of the spacecraft produced by station-based attitude control system and reboost thrusters, recording and transmitting the data, and processing the data on the ground to identify the natural frequencies, damping factors, and shapes of significant vibratory modes. The experiment would likely be a part of the Space Station on-orbit verification. Basic research objectives of MIE are to evaluate and improve methods for analytically modeling large space structures, to develop techniques for performing in-space modal testing, and to validate candidate techniques for in-space modal identification. From an engineering point of view, MIE will provide the first opportunity to obtain vibration data for the fully-assembled structure because SSF is too large and too flexible to be tested as a single unit on the ground. Such full-system data is essential for validating the analytical model of SSF which would be used in any engineering efforts associated with structural or control system changes that might be made to the station as missions evolve over time. Extensive analytical simulations of on-orbit tests, as well exploratory laboratory simulations using small-scale models, have been conducted in-house and under contract to develop a measurement plan and evaluate its potential performance. In particular, performance trade and parametric studies conducted as part of these simulations were used to resolve issues related to the number and location of the measurements, the type of excitation, data acquisition and data processing, effects of noise and nonlinearities, selection of target vibration modes, and the appropriate type of data analysis scheme. The purpose of this talk is to provide an executive-summary-type overview of the modal identification experiment which has emerged from the conceptual design studies conducted to-date. Emphasis throughout is on those aspects of the experiment which should be of interest to those attending the subject utilization conference. The presentation begins with some preparatory remarks to provide background and motivation for the experiment, describe the experiment in general terms, and cite the specific technical objectives. This is followed by a summary of the major results of the conceptual design studies conducted to define the baseline experiment. The baseline experiment which has resulted from the studies is then described.

Kvaternik, Raymond G.↗

Future superconductivity applications in space - A review

High temperature superconductor (HISC) materials and devices can provide immediate applications for many space missions. The in-space thermal environment provides an opportunity to develop, test, and apply this technology to enhance performance and reliability for many applications of crucial importance to NASA. Specifically, the technology development areas include: (1) high current power transmission, (2) microwave components, devices, and antennas, (3) microwave, optical, and infrared sensors, (4) signal processors, (5) submillimeter wave components and systems, (6) ultra stable space clocks, (7) electromagnetic launch systems, and (8) accelerometers and position sensors for flight operations. HTSC is expected to impact NASA's Lunar Bases, Mars exploration, Mission to Earth, and Planetary exploration programs providing enabling and cost-effect technology. A review of the space applications of the HTSC technology is presented. Problem areas in technology development needing special attention are identified.

Krishen, Kumar↗

Tool for simulating space exploration initiative (SEI) operations as a means of obtaining intelligent systems requirements

The Lyndon B. Johnson Space Center Automation and Robotics Division has developed a simulation tool for use in evaluating the feasibility and effectiveness of proposed candidate mission concepts, such as the First Lunar Outpost design reference missions. The tool helps in defining requirements for such missions at the beginning of the definition activities and can be applied iteratively thereafter on a short cycle basis as changes are made to the mission definition. The simulation is applicable to the amount and capabilities of automation and robotics; number and skills of crew; amount of engineering work, science, and in-space materials utilization to be accomplished; impact of provision for maintenance and repair; and flight schedules and manifests. The simulation accounts for supply and demand of resources to accomplish tasks and accounts for elapsed time in carrying out mission processes and tasks.

Erickson, Jon D.↗

Atmospheric sounding with the Lidar In-Space Technology Experiment (LITE)

The Lidar In-Space Technology Experiment (LITE) is being developed by NASA Langley Research Center for a series of flights on the Space Shuttle. Using a three-wavelength Nd:YAG laser and a 1-meter-diameter telescope, the system will be used to study clouds, aerosols in the troposphere and stratosphere, density and temperature perturbations of the stratosphere, and characteristics of the planetary boundary layer. Data collected from the system will be used in studies of atmospheric dynamics, meteorology, climate, the radiation budget, biogeochemical processes, and the hydrologic cycle. Additionally, the data will be used to develop retrieval techniques optimized for a spaceborne configuration and to develop requirements for future operational spaceborne lidar systems.

Winker, D. M.↗

Advanced automation for in-space vehicle processing

The primary objective of this 3-year planned study is to assure that the fully evolved Space Station Freedom (SSF) can support automated processing of exploratory mission vehicles. Current study assessments show that required extravehicular activity (EVA) and to some extent intravehicular activity (IVA) manpower requirements for required processing tasks far exceeds the available manpower. Furthermore, many processing tasks are either hazardous operations or they exceed EVA capability. Thus, automation is essential for SSF transportation node functionality. Here, advanced automation represents the replacement of human performed tasks beyond the planned baseline automated tasks. Both physical tasks such as manipulation, assembly and actuation, and cognitive tasks such as visual inspection, monitoring and diagnosis, and task planning are considered. During this first year of activity both the Phobos/Gateway Mars Expedition and Lunar Evolution missions proposed by the Office of Exploration have been evaluated. A methodology for choosing optimal tasks to be automated has been developed. Processing tasks for both missions have been ranked on the basis of automation potential. The underlying concept in evaluating and describing processing tasks has been the use of a common set of 'Primitive' task descriptions. Primitive or standard tasks have been developed both for manual or crew processing and automated machine processing.

Sklar, Michael↗

The ISES: A non-intrusive medium for in-space experiments in on-board information extraction

The Information Science Experiment System (ISES) represents a new approach in applying advanced systems technology and techniques to on-board information extraction in the space environment. Basically, what is proposed is a 'black box' attached to the spacecraft data bus or local area network. To the spacecraft the 'black box' appears to be just another payload requiring power, heat rejection, interfaces, adding weight, and requiring time on the data management and communication system. In reality, the 'black box' is a programmable computational resource which eavesdrops on the data network, taking and producing selectable, real-time science data back on the network. This paper will present a brief overview of the ISES Concept and will discuss issues related to applying the ISES to the polar platform and Space Station Freedom. Critical to the operation of ISES is the viability of a payload-like interface to the spacecraft data bus or local area network. Study results that address this question will be reviewed vis-a-vis the solar platform and the core space station. Also, initial results of processing science and other requirements for onboard, real-time information extraction will be presented with particular emphasis on the polar platform. Opportunities for a broader range of applications on the core space station will also be discussed.

Murray, Nicholas D.↗

Activities of the Center for Space Construction

The Center for Space Construction (CSC) at the University of Colorado at Boulder is one of eight University Space Engineering Research Centers established by NASA in 1988. The mission of the center is to conduct research into space technology and to directly contribute to space engineering education. The center reports to the Department of Aerospace Engineering Sciences and resides in the College of Engineering and Applied Science. The college has a long and successful track record of cultivating multi-disciplinary research and education programs. The Center for Space Construction is prominent evidence of this record. At the inception of CSC, the center was primarily founded on the need for research on in-space construction of large space systems like space stations and interplanetary space vehicles. The scope of CSC's research has now evolved to include the design and construction of all spacecraft, large and small. Within this broadened scope, our research projects seek to impact the underlying technological basis for such spacecraft as remote sensing satellites, communication satellites, and other special purpose spacecraft, as well as the technological basis for large space platforms. The center's research focuses on three areas: spacecraft structures, spacecraft operations and control, and regolith and surface systems. In the area of spacecraft structures, our current emphasis is on concepts and modeling of deployable structures, analysis of inflatable structures, structural damage detection algorithms, and composite materials for lightweight structures. In the area of spacecraft operations and control, we are continuing our previous efforts in process control of in-orbit structural assembly. In addition, we have begun two new efforts in formal approach to spacecraft flight software systems design and adaptive attitude control systems. In the area of regolith and surface systems, we are continuing the work of characterizing the physical properties of lunar regolith, and we are at work on a project on path planning for planetary surface rovers.

Source record↗

Lithium Battery Space Experiment

The In-Space Technology Experiments Program selected the Jet Propulsion Laboratory to conduct a Phase A study of the Lithium Battery Experiment. The experiment will mark the first time a rechargeable lithium battery will be flown in space. The operation of the battery involves lithium deposition and dissolution processed. Micro gravity influences these processes significantly. The experiment will check the rate capability, discharge voltage, capacity and the phenomena affecting cycle life. The paper describes the design and methodology of this experiment.

Mueller, R.↗