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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

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NASA NTRS1990

Optimal digital control of a Stirling cycle cooler

This short paper describes work in progress on the conceptual design of a control system for a cryogenic cooler intended for use aboard spacecraft. The cooler will produce 5 watts of cooling at 65 K and will be used to support experiments associated with the following: earth observation; atmospheric measurements; infrared, x-ray, and gamma-ray astronomy; and magnetic field characterization. The cooler has been designed and constructed for NASA/GSFC by Philips Laboratories and is described in detail. The cooler has a number of unique design features intended to enhance long life and maintenance free operation in space including use of the high efficiency Stirling thermodynamic refrigeration cycle, linear magnetic motors, clearance-seals, and magnetic bearings. The proposed control system design is based on optimal control theory and is targeted for custom integrated circuit implementation. The resulting control system will meet the following mission requirements: efficiency, reliability, optimal thermodynamic, electrical, and mechanical performance; freedom from operator intervention; light weight; and small size.

Feeley, J.↗

NASA NTRS1974

Design, development and testing of a cryogenic temperature heat pipe for the icicle system

An analytical model was formulated for a cryogenic heat pipe, and thermal and transport analyses were developed to predict the performance characteristics of various heat pipe designs. These analyses permitted optimization of various design parameters. A series of four breadboard heat pipes were fabricated and tested to provide inputs such as internal film coefficients, minimum capillary radii, and wick permeabilities which are required for the analyses. The results of instrumentation, charging, and testing of cryogenic heat pipes were applied to the prototype heat pipes. After a thorough design analysis of three potential heat pipe wicks (slab, artery, and axial groove), the first two were chosen for application to two prototype heat pipes. Detailed designs were made of the two heat pipes and the units were fabricated. Tests were conducted which verified the integrity and safety margin of the design to withstand the internal pressure at ambient temperature and fatigue of thermal cycling. During the acceptance testing in the vacuum chamber, no difficulty was experienced in priming the slab-wick heat pipe and it met the performance design requirements. The artery-wick heat pipe would not prime with nitrogen working fluid for any test conditions.

Trimmer, D. S.↗

NASA NTRS2014

Potential Follow on Experiments for the Zero Boil Off Tank Experiment

Cryogenic Storage &Transfer are enabling propulsion technologies in the direct path of nearly all future human or robotic missions; It is identified by NASA as an area with greatest potential for cost saving; This proposal aims at resolving fundamental scientific issues behind the engineering development of the storage tanks; We propose to use the ISS lab to generate & collect archival scientific data:, raise our current state-of-the-art understanding of transport and phase change issues affecting the storage tank cryogenic fluid management (CFM), develop and validate state-of-the-art CFD models to innovate, optimize, and advance the future engineering designs

Thermodynamics↗

NASA NTRS2000

Microreactor System Design for a NASA In Situ Propellant Production Plant on Mars

The NASA In Situ Resource Utilization (ISRU) program is planning near-term missions to Mars that will include chemical processes for converting the carbon dioxide (CO2) and possibly water from the Martian environment to propellants, oxygen, and other useful chemicals. The use of indigenous resources reduces the size and weight of the payloads from Earth significantly, representing enormous cost savings that make human exploration of Mars affordable. Extraterrestrial chemical processing plants will need to be compact, lightweight, highly efficient under reduced gravity, and extraordinarily reliable for long periods. Microchemical and thermal systems represent capability for dramatic reduction in size and weight, while offering high reliability through massive parallelization. In situ propellant production (ISPP), one aspect of the ISRU program, involves collecting and pressurizing atmospheric CO2, conversion reactions, chemical separations, heat exchangers, and cryogenic storage. A preliminary system design of an ISPP plant based on microtechnology has demonstrated significant size, weight, and energy efficiency gains over the current NASA baseline. Energy management is a strong driver for Mars-based processes, not only because energy is a scarce resource, but because heat rejection is problematic; the low pressure environment makes convective heat transfer ineffective. Energy efficiency gains are largely achieved in the microchemical plant through extensive heat recuperation and energy cascading, which has a small size and weight penalty because the added micro heat exchangers are small. This leads to additional size and weight gains by reducing the required area of waste heat radiators. The microtechnology-based ISPP plant is described in detail, including aspects of pinch analysis for optimizing the heat exchanger network. Three options for thermochemical compression Of CO2 from the Martian atmosphere, adsorption, absorption, and cryogenic freezing, are presented, as well as three options for water decomposition, low temperature electrolysis, high temperature electrolysis, and thermochemical decomposition. Other elements of the plant include Sabatier and reverse water gas shift reactors, water recovery, chemical separations, and cryogenic storage. Data are presented supporting preliminary sizing of components, and results of the system design are compared to the existing NASA baseline that is based on conventional technologies.

TeGrotenhuis, W. E.↗

NASA NTRS1992

Optimization of armored spherical tanks for storage on the lunar surface

A redundancy strategy for reducing micrometeroid armoring mass is investigated, with application to cryogenic reactant storage for a regenerative fuel cell (RFC) on the lunar surface. In that micrometeoroid environment, the cryogenic fuel must be protected from loss due to tank puncture. The tankage must have a sufficiently high probability of survival over the length of the mission so that the probability of system failure due to tank puncture is low compared to the other mission risk factors. Assuming that a single meteoroid penetration can cause a storage tank to lose its contents, two means are available to raise the probability of surviving micrometeoroid attack to the desired level. One can armor the tanks to a thickness sufficient to reduce probability of penetration of any tank to the desired level or add extra capacity in the form of spare tanks that results in survival of a given number out of the ensemble at the desired level. A combination of these strategies (armoring and redundancy) is investigated. The objective is to find the optimum combination which yields the lowest shielding mass per cubic meter of surviving fuel out of the original ensemble. The investigation found that, for the volumes of fuel associated with multikilowatt class cryo storage RFC's, and the armoring methodology and meteoroid models used, storage should be fragmented into small individual tanks. Larger installations (more fuel) pay less of a shielding penalty than small installations. For the same survival probability over the same time period, larger volumes will require less armoring mass per unit volume protected.

Bents, D. J.↗

NASA NTRS1992

Optimization of armored spherical tanks for storage on the lunar surface

Bents, D. J.↗

NASA NTRS1995

The Infrared Telescope in Space (IRTS) Mission

The Infrared Telescope in Space is a cryogenically-cooled NASA/ISAS space survey instrument scheduled for a February, 1995 launch. The telescope optical system is optimized for studies of extended low surface-brightness objects. Four focal-plane instruments cover wavelengths ranging form 1 to 800 microns.

Roellig, Thomas L.↗

NASA NTRS2016

Successful Completion of the JWST OGSE2 Cryogenic Test at JSC Chamber-A While Managing Numerous Challenges

The James Webb Space Telescope (JWST) Optical Telescope Element (OTE) assembly is the largest optically stable infrared-optimized telescope currently being manufactured and assembled, and scheduled for launch in 2018. The JWST OTE, including the primary mirrors, secondary mirror, and the Aft Optics Subsystems (AOS) are designed to be passively cooled and operate at near 45 degrees Kelvin. Due to the size of its large sunshield in relation to existing test facilities, JWST cannot be optically or thermally tested as a complete observatory-level system at flight temperatures. As a result, the telescope portion along with its instrument complement will be tested as a single unit very late in the program, and on the program schedule critical path. To mitigate schedule risks, a set of 'pathfinder' cryogenic tests will be performed to reduce program risks by demonstrating the optical testing capabilities of the facility, characterizing telescope thermal performance, and allowing project personnel to learn valuable testing lessons off-line. This paper describes the 'pathfinder' cryogenic test program, focusing on the recently completed second test in the series called the Optical Ground Support Equipment 2 (OGSE2) test. The JWST OGSE2 was successfully completed within the allocated project schedule while faced with numerous conflicting thermal requirements during cool-down to the final cryogenic operational temperatures, and during warm-up after the cryo-stable optical tests. The challenges include developing a pre-test cool-down and warm-up profiles without a reliable method to predict the thermal behaviors in a rarified helium environment, and managing the test article hardware safety driven by the project Limits and Constraints (L&C's). Furthermore, OGSE2 test included the time critical Aft Optics Subsystem (AOS), a part of the flight Optical Telescope Element that would need to be placed back in the overall telescope assembly integrations. The OGSE2 test requirements included the strict adherence of the project contamination controls due to the presence of the contamination sensitive flight optical elements. The test operations required close coordination of numerous personnel while they being exposed and trained for the 'final' combined OTE and instrument cryo-test in 2017. This paper will also encompass the OGSE2 thermal data look-back review.

JWST OGSE2 Cryogenic Test↗

NASA NTRS2003

Aging Optimization of Aluminum-Lithium Alloy C458 for Application to Cryotank Structures

Compared with aluminum alloys such as 2219, which is widely used in space vehicle for cryogenic tanks and unpressurized structures, aluminum-lithium alloys possess attractive combinations of lower density and higher modulus along with comparable mechanical properties. These characteristics have resulted in the successful use of the aluminum-lithium alloy 2195 (Al-1.0 Li-4.0 Cu-0.4 Mg-0.4 Ag-0.12 Zr) for the Space Shuttle External Tank, and the consideration of newer U.S. aluminum-lithium alloys such as L277 and C458 for future space vehicles. These newer alloys generally have lithium content less than 2 wt. % and their composition and processing have been carefully tailored to increase the toughness and reduce the mechanical property anisotropy of the earlier generation alloys such 2090 and 8090. Alloy processing, particularly the aging treatment, has a significant influence on the strength-toughness combinations and their dependence on service environments for aluminum-lithium alloys. Work at NASA Marshall Space Flight Center on alloy 2195 has shown that the cryogenic toughness can be improved by employing a two-step aging process. This is accomplished by aging at a lower temperature in the first step to suppress nucleation of the strengthening precipitate at sub-grain boundaries while promoting nucleation in the interior of the grains. Second step aging at the normal aging temperature results in precipitate growth to the optimum size. A design of experiments aging study was conducted for plate. To achieve the T8 temper, Alloy C458 (Al-1.8 Li-2.7 Cu-0.3 Mg-0.08 Zr-0.3 Mn-0.6 Zn) is typically aged at 300F for 24hours. In this study, a two-step aging treatment was developed through a comprehensive 2(exp 4) full factorial design of experiments study and the typical one-step aging used as a reference. Based on the higher lithium content of C458 compared with 2195, the first step aging temperature was varied between 175F and 250F. The second step aging temperatures was varied between 275F and 325F, which is in the range of the single-step aging temperature. The results of the design of experiments used for the T8 temper as well as a smaller set of experiments for the T6 temper will be presented. The process of selecting the optimum aging treatment, based on the measured mechanical properties at room and cryogenic temperature as well as the observed deformation mechanisms, will be presented in detail. The implications for the use of alloy C458 in cryotanks will be discussed.

Sova, B. J.↗

NASA NTRS2003

Aging Optimization of Aluminum-Lithium Alloy C458 for Application to Cryotank Structures

Compared with aluminum alloys such as 2219, which is widely used in space vehicle for cryogenic tanks and unpressurized structures, aluminum-lithium alloys possess attractive combinations of lower density and higher modulus along with comparable mechanical properties. These characteristics have resulted in the successful use of the aluminum-lithium alloy 2195 (Al-1.0 Li-4.0 Cu-0.4 Mg-0.4 Ag-0.12 Zr) for the Space Shuttle External Tank, and the consideration of newer U.S. aluminum-lithium alloys such as L277 and C458 for future space vehicles. These newer alloys generally have lithium content less than 2 wt. % and their composition and processing have been carefully tailored to increase the toughness and reduce the mechanical property anisotropy of the earlier generation alloys such 2090 and 8090. Alloy processing, particularly the aging treatment, has a significant influence on the strength-toughness combinations and their dependence on service environments for aluminum-lithium alloys. Work at NASA Marshall Space Flight Center on alloy 2195 has shown that the cryogenic toughness can be improved by employing a two-step aging process. This is accomplished by aging at a lower temperature in the first step to suppress nucleation of the strengthening precipitate at sub-grain boundaries while promoting nucleation in the interior of the grains. Second step aging at the normal aging temperature results in precipitate growth to the optimum size. A design of experiments aging study was conducted for plate. To achieve the T8 temper, Alloy C458 (Al-1.8 Li-2.7 Cu-0.3 Mg- 0.08 Zr-0.3 Mn-0.6 Zn) is typically aged at 300 F for 24 hours. In this study, a two-step aging treatment was developed through a comprehensive 24 full factorial design of experiments study and the typical one-step aging used as a reference. Based on the higher lithium content of C458 compared with 2195, the first step aging temperature was varied between 175 F and 250 F. The second step aging temperatures was varied between 275 F and 325 F, which is in the range of the single-step aging temperature. The results of the design of experiments used for the T8 temper as well as a smaller set of experiments for the T6 temper will be presented. The process of selecting the optimum aging treatment, based on the measured mechanical properties at room and cryogenic temperature as well as the observed deformation mechanisms, will be presented in detail. The implications for the use of alloy C458 in cryotanks will be discussed.

Sova, B. J.↗

NASA NTRS2003

Aging Optimization of Aluminum-Lithium Alloy L277 for Application to Cryotank Structures

Sova, B. J.↗

NASA NTRS2004

Small Mercury Ion Clock for On-board Spacecraft Navigation

I.Small Ion Clock Approach and Heritage: a) No lasers, uwave cavities, cryogenics, atomic beams, etc. b) Ions are electrically shuttled between separate optical and microwave traps. II. Each trap is optimized for its task: quadrupole for optical state selection; multi-pole for microwave clock. a) Very good stability shown in USNO. Timescale running "open loop." III. "Open loop" operation means no self-measurements of frequency offsets: (Zeeman, ion temperature,... etc.) a) Fewer parts and procedures, produces stable output continuously. IV. Ion clock is not so sensitive to temperature fluctuations a) Measured u:nshielded temperature coefficient of few 10(exp -15) per C. b) No bulky temperature isolation needed.

Prestage, John D.↗

NASA NTRS2010

2010 ESMD Faculty Fellowship Project

This slide presentation reviews is composed of 6 individual sections. The first is a introductory section that explains the Exploration Systems Mission Directorate (ESMD) Faculty Fellowship Project, the purpose of which is to prepare selected university faculty to work with senior design students to complete projects that have potential to contribute to NASA objectives. The following university presentations represent the chosen projects: (1) the use of Exploration Toolset for the Optimization of Launch and Space Systems (X-TOOLSS) to optimize the Lunar Wormbot design; (2) development of Hardware Definition Language (HDL) realization of ITU G.729 for FGPA; (3) cryogenic fluid and electrical quick connect system and a lunar regolith design; (4) Lunar Landing Pad development; and (5) Prognostics for complex systems.

Carmen, Christina L.↗

NASA NTRS2012

Thermodynamic Vent System for an On-Orbit Cryogenic Reaction Control Engine

A report discusses a cryogenic reaction control system (RCS) that integrates a Joule-Thompson (JT) device (expansion valve) and thermodynamic vent system (TVS) with a cryogenic distribution system to allow fine control of the propellant quality (subcooled liquid) during operation of the device. It enables zero-venting when coupled with an RCS engine. The proper attachment locations and sizing of the orifice are required with the propellant distribution line to facilitate line conditioning. During operations, system instrumentation was strategically installed along the distribution/TVS line assembly, and temperature control bands were identified. A sub-scale run tank, full-scale distribution line, open-loop TVS, and a combination of procured and custom-fabricated cryogenic components were used in the cryogenic RCS build-up. Simulated on-orbit activation and thruster firing profiles were performed to quantify system heat gain and evaluate the TVS s capability to maintain the required propellant conditions at the inlet to the engine valves. Test data determined that a small control valve, such as a piezoelectric, is optimal to provide continuously the required thermal control. The data obtained from testing has also assisted with the development of fluid and thermal models of an RCS to refine integrated cryogenic propulsion system designs. This system allows a liquid oxygenbased main propulsion and reaction control system for a spacecraft, which improves performance, safety, and cost over conventional hypergolic systems due to higher performance, use of nontoxic propellants, potential for integration with life support and power subsystems, and compatibility with in-situ produced propellants.

Hurlbert, Eric A.↗

NASA NTRS2016

Solar Array (Radiated/Non-Radiated): Materials Characterization and Cryogenic Thermal Cycling Qualification for the Planned Europa Clipper Mission (ECM)

Two special instruments were custom built for our critical study and manufactured and employed to test the SA materials of interest to cryogenic temperature conditions. We have procured custom manufactured two independent systems such as Thermo -Mechanical Analyzer (TMA) with Three Point Bend Probe (TPBP) module and Dilatometer. TMA can be used to measure Young’ s modulus or elastic modulus (e -modulus). Dilatometer can be used to measure Co -efficient of Thermal Expansion (CTE). We have optimized the materials configuration to measure physical properties of radiated and non -radiated materials for CTE and e -modulus, which will be useful to assess materials and processes reliability for cryogenic temperature applications. We have successfully implemented for some materials that are of interest to solar panels for the planned ECM project to measure CTE and Young's modulus. Also a separate study was undertaken to thermal cycle qualify SAs for ECM project. One can do thermal cycling to temperatures of 50 K and 133 K using liquid Helium (Lq He). This is in reality exorbitantly too expensive and is also inefficient. Furthermore, this is not technically controllable test to 133 K and 50 K temperatures. This is also too expensive to accomplish. Therefore, a vacuum set -up was made along with a cryostat successfully. This is a closed loop system where we do not lose the Helium gas. We were able to get to 35 K for a given test coupon size. These temperatures are lower than what we would intend to qualify the solar array technologies. This will allow to have some margin at cold temperatures. We successfully completed the qualification of solar array technologies down to 50 K temperatures. This is the first time we are reporting this accomplishment. In this paper, we will present the solar array materials properties for cryogenic temperatures down to 20 K temperatures and the thermal cycling qualification test results from 133 K to 50 K for three times the mission life of 120 thermal cycles to meet JPL Design.

Ramesham, Rajeshuni↗

NASA NTRS2010

Enhancements to the NASA/Goddard Space Flight Center (GSFC) Space Environment Simulator (SES) Facility to Support Cryogenic Testing of the James Webb Space Telescope (JWST) Integrated Science Instrument Module (ISIM)

NASA is the mission lead for the James Webb Space Telescope (JWST), the next of the "Great Observatories", scheduled for launch in 2014. It is directly responsible for the integration and test of the Integrated Science Instrument Module (ISIM), which includes a composite truss structure provided by NASA, and four science instruments sponsored and provided by NASA, the European Space Agency (ESA), the Canadian Space Agency (CSA), and the European Consortium (EC). Three of the four instruments are passively cooled and designed to operate at temperatures in the 36K to 40K range, and the fourth instrument is actively cooled to approximately 6K. The ISIM will undergo several performance tests at various levels of integration in the NASA Goddard Space Flight Center's (GSFC) Space Environment Simulator (SES), GSFC's largest thermal vacuum chamber. These activities range from Cryo-cycling the bare flight composite structure to thermal balance and performance testing of the full ISIM module. This paper describes the enhancements made to the SES chamber in order to support all cryogenic thermal vacuum testing of the ISIM. Upgrades discussed include: design and fabrication of a very large, removable and reconfigurable helium shroud; a new valve box permitting independent flow control of gaseous helium (GHe) to up to ten zones; and development of in-situ 3-dimensional photogrammetry capability in a cryogenic environment. Also presented will be select results from several facility tests already conducted to verify the chamber capabilities and optimize operational procedures, including the Helium Shroud -03 Configuration Acceptance Test, and the Helium Shroud -01 Configuration Chamber Certification Test.

Cleveland, Paul↗

NASA NTRS2010

Optimal Flow Control Design

In support of the Blended-Wing-Body aircraft concept, a new flow control hybrid vane/jet design has been developed for use in a boundary-layer-ingesting (BLI) offset inlet in transonic flows. This inlet flow control is designed to minimize the engine fan-face distortion levels and the first five Fourier harmonic half amplitudes while maximizing the inlet pressure recovery. This concept represents a potentially enabling technology for quieter and more environmentally friendly transport aircraft. An optimum vane design was found by minimizing the engine fan-face distortion, DC60, and the first five Fourier harmonic half amplitudes, while maximizing the total pressure recovery. The optimal vane design was then used in a BLI inlet wind tunnel experiment at NASA Langley's 0.3-meter transonic cryogenic tunnel. The experimental results demonstrated an 80-percent decrease in DPCPavg, the reduction in the circumferential distortion levels, at an inlet mass flow rate corresponding to the middle of the operational range at the cruise condition. Even though the vanes were designed at a single inlet mass flow rate, they performed very well over the entire inlet mass flow range tested in the wind tunnel experiment with the addition of a small amount of jet flow control. While the circumferential distortion was decreased, the radial distortion on the outer rings at the aerodynamic interface plane (AIP) increased. This was a result of the large boundary layer being distributed from the bottom of the AIP in the baseline case to the outer edges of the AIP when using the vortex generator (VG) vane flow control. Experimental results, as already mentioned, showed an 80-percent reduction of DPCPavg, the circumferential distortion level at the engine fan-face. The hybrid approach leverages strengths of vane and jet flow control devices, increasing inlet performance over a broader operational range with significant reduction in mass flow requirements. Minimal distortion level requirements are met using vanes alone, avoiding engine stall and increasing robustness of this hybrid inlet flow control approach. This design applies to aerospace applications needing flush-mounted boundary-layer-ingesting inlets.

Allan, Brian↗

NASA NTRSDate not supplied

Extreme Environment Hot Fire Durability of Post-Processed Additively Manufactured GRCop-Alloy Combustion Chambers in LOX/Hydrogen and LOX/Methane

Extreme environment survivability of metal additive manufactured (AM) GRCop-alloy thrust chambers has been demonstrated in different bi-propellants at near stoichiometric and even oxygen rich combustion. GRCop-alloy chambers tested at NASA Marshall Space Flight Center (MSFC) have accumulated over 26,000 seconds of hot fire duration and over 500 starts. These chambers are produced using an AM process called laser powder bed fusion (L-PBF). A major feature of this process is high wall surface roughness which can be customized in post processing to leverage various performance advantages. Post-processing can include heat treatment, final machining, polishing, and welding and is key to hardware survivability in extreme environments. Surface finish enhancement techniques were applied to the hot wall and coolant channels to reduce the overall total heat load to the chamber walls. Performance optimization of various thrust class TCA’s is a strategic technology goal of NASA MSFC. Three different chamber geometries using cryogenic methane and de-ionized water as coolants were hot fire tested to obtain their life cycle, pressure drop, and heat load performances. Several 1.2K lbf LOX/H2 chambers, 1K lbf LOX/CH4 chambers, and 7K lbf LOX/CH4 chambers were tested. All post-processed configurations performed remarkably well when subjected to extreme hot fire test conditions. Streaking and blanching due to localized oxygen rich conditions were observed on some test articles in their as-built surface finish state. However, this is actually a function of the injector mixing and only serves to further establish the durability of L-PBF GRCop-alloy thrust chambers. Several different polishing techniques were applied to the hot wall and integrated coolant channels prior to hot fire testing and their performances assessed. Overall, AM produced GRCop chambers are extremely reliable, durable, and customizable to the desired performance metrics.

grcop↗