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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 145 records · Page 8

Rover imaging system for the Mars rover/sample return mission

In the past year, the conceptual design of a panoramic imager for the Mars Environmental Survey (MESUR) Pathfinder was finished. A prototype camera was built and its performace in the laboratory was tested. The performance of this camera was excellent. Based on this work, we have recently proposed a small, lightweight, rugged, and highly capable Mars Surface Imager (MSI) instrument for the MESUR Pathfinder mission. A key aspect of our approach to optimization of the MSI design is that we treat image gathering, coding, and restoration as a whole, rather than as separate and independent tasks. Our approach leads to higher image quality, especially in the representation of fine detail with good contrast and clarity, without increasing either the complexity of the camera or the amount of data transmission. We have made significant progress over the past year in both the overall MSI system design and in the detailed design of the MSI optics. We have taken a simple panoramic camera and have upgraded it substantially to become a prototype of the MSI flight instrument. The most recent version of the camera utilizes miniature wide-angle optics that image directly onto a 3-color, 2096-element CCD line array. There are several data-taking modes, providing resolution as high as 0.3 mrad/pixel. Analysis tasks that were performed or that are underway with the test data from the prototype camera include the following: construction of 3-D models of imaged scenes from stereo data, first for controlled scenes and later for field scenes; and checks on geometric fidelity, including alignment errors, mast vibration, and oscillation in the drive system. We have outlined a number of tasks planned for Fiscal Year '93 in order to prepare us for submission of a flight instrument proposal for MESUR Pathfinder.

Source record↗

Lyophilization for Water Recovery III, System Design

Mixed liquid/solid wastes, including feces, water processor effluents, and food waste, can be lyophilized (freeze-dried) to recover the water they contain and stabilize the solids that remain. Our previous research has demonstrated the potential benefits of using thermoelectric heat pumps to build a lyophilizer for processing waste in microgravity. These results were used to build a working prototype suitable for ground- based human testing. This paper describes the prototype design and presents results of functional and performance tests.

Litwiller, Eric↗

Initial Field Testing in the Deep Subsurface for the Thermal Breakout Project for Measuring In Situ Stress

The current state-of-the-art technology for in situ stress measurements involves an integrated approach that combines borehole breakout observations, drilling-induced tensile fractures, and hydraulic fracturing tests (i.e., mini-fracs); however, this methodology has several limitations that often prevent successful in situ stress measurements. One major limitation is that breakouts do not appear in every borehole and are generally a natural occurrence that cannot easily be controlled. Because borehole breakouts are used to measure the maximum horizontal in situ stress magnitude, the absence of borehole breakouts presents a major data gap for in situ stress measurements. As a response to this data gap a new thermal breakout technology is being developed that will provide a method for thermally inducing borehole breakouts and obtaining consistent measurements of the maximum horizontal stress magnitude. This thermal breakout technology involves heating the borehole and increasing the thermoelastic compressive stress in the rock until a breakout develops, which is directly correlated to the maximum horizontal stress magnitude. An initial component of the thermal breakout project involves developing a prototype downhole tool and performing field testing in the deep subsurface. The primary objective of the initial tool development and field testing is to provide a physical proof of concept for the thermal breakout technology. Three thermal breakout field tests were performed at approximately 4850 feet deep in the Sanford Underground Research Facility. Each test was performed in a borehole that had been previously used for overcoring stress measurements. The third and final test successfully created two diametrically opposed breakouts after deploying the thermal breakout tool for approximately 3 hours of continuous heating. Post-analysis of the thermally induced breakouts confirmed that the thermal breakout orientation directly corresponds to the known in situ stress orientation and magnitude.

Voegeli, Sam↗

How Useful are Conventional I–Vs for Performance Calibration of Single- and Two-Junction Perovskite Solar Cells? A Statistical Analysis of Performance Data on ≈200 Cells from 30 Global Sources

As perovskite photovoltaics (PV) advance from the laboratory to commercial prototypes, their accurate and reliable performance testing is becoming increasingly important. The well-documented dynamic response of perovskite solar cells to an external applied voltage has led to the development of steady-state performance measurement methods; however, these methods have not been widely adopted by the perovskite PV community. A key reason for this is that steady-state measurement methods take tens of minutes to complete, as opposed to conventional "fast" current-voltage (I-V) measurements usually lasting a few seconds. Fast I-Vs arise from a snapshot, almost always not a steady-state condition of the device; however, given their widespread use, the question arises: how do performance parameters of perovskite PV compare when measured with fast I-V and with a steady-state method? Results compiled from approximately 200 perovskite PV cells, including single junction, and two-terminal perovskite-perovskite and perovskite-Si tandems, show that fast I-Vs can provide a useful measure of the open-circuit voltage of the devices, while the short-circuit current and the overall efficiency can be widely misestimated. Here, the implications of these findings on performance testing protocols are discussed and possible options for fast and accurate testing of perovskite PV are proposed.

14 SOLAR ENERGY↗

Development of readout electronics for the CMS ME0 muon detector

The Large Hadron Collider (LHC) in the High Luminosity (HL-LHC) era will be upgraded to deliver instantaneous luminosities up to 5 X 10 34 cm -2 s -1 , five times more than the original design value. In order to maintain performance of the Compact Muon Solenoid (CMS) Experiment under these conditions, ME0 is one of the new muon detectors to be added, along with GE1/1, GE2/1, RE3/1 and RE4/1. ME0 uses the triple Gas Electron Multiplier (GEM) technology and is designed to cover the far-forward region of 2.0 < |η| < 2.8. Further, the readout electronics for ME0 must be designed to deal with high data rates and be sufficiently radiation hard to operate very close to the beamline. The design and development status of the readout electronics for ME0 are presented, along with recent results from integration tests performed using the latest electronics prototypes with GEM chambers.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗

Statistical Performance Analysis on Approximately 320 Perovskite Single- and Two-Junction Solar Cells and Modules from >30 Global Sources

As perovskite photovoltaics (PV) advance from the laboratory to commercial prototypes, their accurate and reliable performance testing is becoming increasingly important. The well documented dynamic response of perovskite solar cells to an external applied voltage has led to the development of steady-state performance measurement methods; however, these methods have not been widely adopted by the perovskite PV community. A key reason for this is that steady-state measurement methods take tens of minutes to complete, as opposed to conventional "fast" current-voltage (I-V) measurements usually lasting a few seconds. Fast I-Vs arise from a snapshot, almost always not a steady-state condition of the device; however, given their widespread use, the question arises: how do performance parameters of perovskite PV compare when measured with fast I-V and with a steady-state method? We compile results from ca. 320 perovskite PV cells and modules, including single junction, and two-terminal perovskite-perovskite and perovskite-Si tandems, and show that fast I-Vs can provide a useful measure of the open-circuit voltage of the devices, while the short-circuit current and the overall efficiency can be widely misestimated. We discuss implications of these findings on performance testing protocols and propose possible options for fast and accurate testing of perovskite PV.

asymptotic↗

Lessons Learned From the Prototypes of the MQXFA Low-Beta Quadrupoles for HL-LHC and Status of Production in the US

With the successful test of the first two pre-series magnets the US HL-LHC Accelerator Upgrade Project has started production of the MQXFA magnets to be used in Q1/Q3 inner triplet elements of the HL-LHC. This good start comes after the test of two prototypes with limited performance, and it demonstrates the importance of learning from past issues. Therefore, in this paper we want to share the most important lessons learned so far, focusing on those which may be more interesting for similar projects. Additionally, we will present the status of MQXFA fabrication in the US.

43 PARTICLE ACCELERATORS↗

A microprocessor-based position control system for a telescope secondary mirror

The pointing requirements for the Shuttle IR Telescope Facility (SIRTF), which consists of an 0.85-m cryogenically cooled IR telescope, call for an image stability of 0.25 arcsec. Attention is presently given to a microprocessor-based position control system developed for the control of the SIRTF secondary mirror, employing a special control law (to minimize energy dissipation), a precision capacitive position sensor, and a specially designed power amplifier/actuator combination. The microprocessor generates the command angular position and rate waveforms in order to maintain a 90 percent dwell time/10 percent transition time ratio independently of chop frequency or amplitude. Performance and test results of a prototype system designed for use with a demonstration model of the SIRTF focal plane fine guidance sensor are presented.

Lorell, K. R.↗

Heat pipe modeling and simulation

Presented herein is a parametric study of the defining equations which govern the steady state operational characteristics of the Grumman Monogroove Dual Passage Heat Pipe. These defining equations are combined to develop a mathematical model which describes and predicts the operational and performance capabilities of a specific heat pipe, given the necessary physical characteristics and working fluid. Included is a brief review of the current literature, a discussion of the governing equations, and a description of both the mathematical and computer model. Final results of preliminary test runs of the model are presented and compared with experimental tests performed by Grumman on actual prototypes.

Peterson, G. P.↗

Capsulation Satellite or CapSat: A Low-Cost, Reliable, Rapid-Response Spacecraft Platform

The National Aeronautics and Space Administration (NASA) Goddard's Rideshare Office estimates that between 2013 and 2022, NASA launches of primary satellites will have left unused more than 20,371 kilograms of excess capacity. This equates to hundreds of millions of dollars in launch-vehicle costs going unutilized. To fill this void with a standard CubeSat or SmallSat spacecraft platform, which when required to be more reliable, still will cost in the neighborhood of $1M a kilogram, making it prohibitively expensive. A newly proposed solution, which NASA is pursuing, is called the Capsulation Satellite or CapSat. CapSat is a modularized, pressurized, thermally controlled spacecraft designed to host ruggedized commercially available instrumentation in a terrestrial like environment on orbit. Using a technique that is under review for a patent, CapSat actively manages internal air temperatures in a manner similar to a household thermostat. This gives CapSat high-thermal stability, which, in turn, provides component longevity. CapSat was specifically designed to take advantage of the United States Air Force (USAF) Rideshare Program and the Evolved Expendable Launch Vehicle Secondary Payload Adaptor, or ESPA ring. The ESPA ring comes in two sizes: standard and Grande. CapSat primarily will take advantage of the ESPA Grande to provide a 300-kilogram payload capability per attachment point, with up to four attachment points per ring. This approach combines a high-mass capability with a proven Rideshare mechanical interface and secondary payload management infrastructure. Opportunities for ESPA based co-manifests are continuing to expand. The CapSat program is currently funded to design and build a limited prototype and perform thermal-vacuum testing. CapSat is currently in the concept/study phase for both single missions and constellation of earth- and space-observing missions. One of these studies includes land imaging using state-of-the-art advanced infrared detector technology. This paper will report on the current status of the CapSat hardware design, testing, and results as well as any openly available advanced concept study results. The CapSat solution is intended to be a game-changing paradigm shift. CapSat will repurpose currently available, already-proven technology to reduce spaceflight hardware costs to less than $50,000 per kilogram.

Burt, Joe↗

IMPACT User Experience

NASA Human Research Project (HRP) and Exploration Medical Capabilities (ExMC) team identified a need to implement a human-centered design approach for a computational tool that performs detailed trade space analysis and research prioritization, known as Informing Mission Planning via Analysis of Complex Tradespaces (IMPACT). IMPACT processes numerous parameters such as space vehicle design, mission objectives, evacuation capability, medical events, and mission constraint, including but not limited to; duration, mass, volume, equipment, and medical capability, each with complex and interconnected relationships. The ability for users to navigate through these complexities and provide an intuitive report is critical to aiding stakeholders in the decision-making process of future missions. In this presentation we will discuss how the IMPACT team has applied human-centered design strategies to improve system usability by modelling human-system integration (i.e., task analysis) with the MagicDraw SysML modelling application and performing A/B testing of user interface prototypes.

S Ozbek↗

Full-Scale Crash Test and Finite Element Simulation of a Composite Prototype Helicopter

A full-scale crash test of a prototype composite helicopter was performed at the Impact Dynamics Research Facility at NASA Langley Research Center in 1999 to obtain data for validation of a finite element crash simulation. The helicopter was the flight test article built by Sikorsky Aircraft during the Advanced Composite Airframe Program (ACAP). The composite helicopter was designed to meet the stringent Military Standard (MIL-STD-1290A) crashworthiness criteria and was outfitted with two crew and two troop seats and four anthropomorphic dummies. The test was performed at 38-ft/s vertical and 32.5-ft/s horizontal velocity onto a rigid surface. An existing modal-vibration model of the Sikorsky ACAP helicopter was converted into a model suitable for crash simulation. A two-stage modeling approach was implemented and an external user-defined subroutine was developed to represent the complex landing gear response. The crash simulation was executed with a nonlinear, explicit transient dynamic finite element code. Predictions of structural deformation and failure, the sequence of events, and the dynamic response of the airframe structure were generated and the numerical results were correlated with the experimental data to validate the simulation. The test results, the model development, and the test-analysis correlation are described.

Jackson, Karen E.↗

Progress in Acoustic Transmission of Power through Walls

A document presents updated information on implementation of the wireless acoustic-electric feed-through (WAEF) concept, which was reported in Using Piezoelectric Devices To Transmit Power Through Walls (NPO-41157), NASA Tech Briefs, Vol. 32, No. 6 (June 2008), page 70. To recapitulate: In a basic WAEF setup, a transmitting piezoelectric transducer on one side of a wall is driven at resonance to excite ultrasonic vibrations in the wall. A receiving piezoelectric transducer on the opposite side of the wall converts the vibrations back to an ultrasonic AC electric signal, which is then detected and otherwise processed in a manner that depends on the modulation (if any) applied to the signal and whether the signal is used to transmit power, data, or both. The present document expands upon the previous information concerning underlying physical principles, advantages, and potential applications of WAEF. It discusses the design and construction of breadboard prototype piezoelectric transducers for WAEF. It goes on to present results of computational simulations of performance and results of laboratory tests of the prototypes. In one notable test, a 100-W light bulb was lit by WAEF to demonstrate the feasibility of powering a realistic load.

Sherrit,Stewart↗

Solar Decarbonization of Paraffin Dehydrogenation Through Particle Heat Carriers (Final Technical Report)

This project focuses on solutions to decarbonize high-temperature catalytic processes using solar thermal heat. The primary project goal is to show the validity of a moving packed bed reactor for propane dehydrogenation using catalyst particles as the heat carrier for the reaction, which can be heated by concentrated solar energy in a particle receiver. This concept, if further developed, may provide a cost-effective pathway for converting lower value gases to important chemical precursors for industrial materials using only renewable energy. The project was divided into six tasks. In Task 1, DFT calculations were performed to understand the role of Pt and Sn in the catalytic dehydrogenation reaction. In Task 2 chemical kinetics measurements were made for several catalyst formulations at high temperatures. In Task 3, the solar absorptance of catalyst particles was compared to the absorptance of commonly used materials in particle receivers. In Task 4, numerical models were developed which could predict performance of the complete system and predict specific temperatures in the system. In Task 5, a prototype system was designed, fabricated, and tested to show the validity of the concept. Task 6 concerned project management activities. Experiments with the prototype showed repeatable thermal performance at temperatures targeted for the reaction. A limited set of tests were done with active catalyst and propane dehydrogenation, showing conversion of propane to propylene with a range of conversions and selectivities. The results are promising, and the prototype designed was reliable during testing, and the team expects that further development of the prototype would yield improved results. A numerical model framework based on coupled fluid and particle mechanics was developed with high computational efficiency using GPU calculations. The model may prove highly useful for evaluating other high-temperature particle systems. However, it was determined that simpler porous media models were good fits for the needs of the current moving packed bed concept. Data showing strong solar absorption of the particles validates the plan of using existing solar particle receivers with only a change in the particle type. Catalyst investigation showed that Pt 1 Sn 3 is the most viable candidate for developing PtSn catalysts for high temperature propane dehydrogenation, considering the balance of activity, selectivity, and deactivation. This project completed an initial study of various factors needed to incorporate a moving bed catalytic reactor for propane dehydrogenation into a concentrated solar thermal particle system. Future developments may allow this technology to be scaled up and help to use solar thermal energy to decarbonize not only the propane dehydrogenation reaction, but other gas-solid catalytic reactions at similar temperatures.

14 SOLAR ENERGY↗

Evaluation of Candidate Millimeter Wave Sensors for Synthetic Vision

The goal of the Synthetic Vision Technology Demonstration Program was to demonstrate and document the capabilities of current technologies to achieve safe aircraft landing, take off, and ground operation in very low visibility conditions. Two of the major thrusts of the program were (1) sensor evaluation in measured weather conditions on a tower overlooking an unused airfield and (2) flight testing of sensor and pilot performance via a prototype system. The presentation first briefly addresses the overall technology thrusts and goals of the program and provides a summary of MMW sensor tower-test and flight-test data collection efforts. Data analysis and calibration procedures for both the tower tests and flight tests are presented. The remainder of the presentation addresses the MMW sensor flight-test evaluation results, including the processing approach for determination of various performance metrics (e.g., contrast, sharpness, and variability). The variation of the very important contrast metric in adverse weather conditions is described. Design trade-off considerations for Synthetic Vision MMW sensors are presented.

Alexander, Neal T.↗

Skipper-CCD sensors for the Oscura experiment: requirements and preliminary tests

Oscura is a proposed multi-kg skipper-CCD experiment designed for a dark matter (DM) direct detection search that will reach unprecedented sensitivity to sub-GeV DM-electron interactions with its 10 kg detector array. Oscura is planning to operate at SNOLAB with 2070 m overburden, and aims to reach a background goal of less than one event in each electron bin in the 2–10 electron ionization-signal region for the full 30 kg-year exposure, with a radiation background rate of 0.01 dru.[1 dru (differential rate unit) corresponds to 1 event/kg/day/keV.] In order to achieve this goal, Oscura must address each potential source of background events, including instrumental backgrounds. In this work, we discuss the main instrumental background sources and the strategy to control them, establishing a set of constraints on the sensors' performance parameters. We present results from the tests of the first fabricated Oscura prototype sensors, evaluate their performance in the context of the established constraints and estimate the Oscura instrumental background based on these results.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗

Fission Power System Technology for NASA Exploration Missions

Under the NASA Exploration Technology Development Program, and in partnership with the Department of Energy (DOE), NASA is conducting a project to mature Fission Power System (FPS) technology. A primary project goal is to develop viable system options to support future NASA mission needs for nuclear power. The main FPS project objectives are as follows: 1) Develop FPS concepts that meet expected NASA mission power requirements at reasonable cost with added benefits over other options. 2) Establish a hardware-based technical foundation for FPS design concepts and reduce overall development risk. 3) Reduce the cost uncertainties for FPS and establish greater credibility for flight system cost estimates. 4) Generate the key products to allow NASA decisionmakers to consider FPS as a preferred option for flight development. In order to achieve these goals, the FPS project has two main thrusts: concept definition and risk reduction. Under concept definition, NASA and DOE are performing trade studies, defining requirements, developing analytical tools, and formulating system concepts. A typical FPS consists of the reactor, shield, power conversion, heat rejection, and power management and distribution (PMAD). Studies are performed to identify the desired design parameters for each subsystem that allow the system to meet the requirements with reasonable cost and development risk. Risk reduction provides the means to evaluate technologies in a laboratory test environment. Non-nuclear hardware prototypes are built and tested to verify performance expectations, gain operating experience, and resolve design uncertainties.

Mason, Lee↗