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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 73 records · Page 4

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NASA NTRS2001

Robust Low Cost Liquid Rocket Combustion Chamber by Advanced Vacuum Plasma Process

Next-generation, regeneratively cooled rocket engines will require materials that can withstand high temperatures while retaining high thermal conductivity. Fabrication techniques must be cost efficient so that engine components can be manufactured within the constraints of shrinking budgets. Three technologies have been combined to produce an advanced liquid rocket engine combustion chamber at NASA-Marshall Space Flight Center (MSFC) using relatively low-cost, vacuum-plasma-spray (VPS) techniques. Copper alloy NARloy-Z was replaced with a new high performance Cu-8Cr-4Nb alloy developed by NASA-Glenn Research Center (GRC), which possesses excellent high-temperature strength, creep resistance, and low cycle fatigue behavior combined with exceptional thermal stability. Functional gradient technology, developed building composite cartridges for space furnaces was incorporated to add oxidation resistant and thermal barrier coatings as an integral part of the hot wall of the liner during the VPS process. NiCrAlY, utilized to produce durable protective coating for the space shuttle high pressure fuel turbopump (BPFTP) turbine blades, was used as the functional gradient material coating (FGM). The FGM not only serves as a protection from oxidation or blanching, the main cause of engine failure, but also serves as a thermal barrier because of its lower thermal conductivity, reducing the temperature of the combustion liner 200 F, from 1000 F to 800 F producing longer life. The objective of this program was to develop and demonstrate the technology to fabricate high-performance, robust, inexpensive combustion chambers for advanced propulsion systems (such as Lockheed-Martin's VentureStar and NASA's Reusable Launch Vehicle, RLV) using the low-cost VPS process. VPS formed combustion chamber test articles have been formed with the FGM hot wall built in and hot fire tested, demonstrating for the first time a coating that will remain intact through the hot firing test, and with no apparent wear. Material physical properties and the hot firing tests are reviewed.

Holmes, Richard↗

NASA NTRS2013

Overview and Recent Accomplishments of the Advanced Mirror Technology Development (AMTD) for Large Aperture UVOIR Space Telescopes Project

Per Astro2010, a new, larger UVO telescope is needed to answer fundamental scientific questions, such as: is there life on Earth-like exoplanets; how galaxies assemble stellar populations; how baryonic matter interacts with intergalactic medium; and how solar systems form and evolve. And, present technology is not mature enough to affordably build and launch any potential UVO concept. Advanced Mirror Technology Development (AMTD) is a funded SAT project. Our objective is to mature to TRL-6 the critical technologies needed to produce 4-m or larger flight-qualified UVOIR mirrors by 2018 so that a viable mission can be considered by the 2020 Decadal Review. AMTD uses a science-driven systems engineering approach. We mature technologies required to enable the highest priority science AND result in a high-performance low-cost low-risk system. To provide the science community with options, we are pursuing multiple technology paths. We have assembled an outstanding team from academia, industry, and government with extensive expertise in astrophysics and exoplanet characterization, and in the design/manufacture of monolithic and segmented space telescopes. One of our key accomplishments is that we have derived engineering specifications for advanced normal-incidence monolithic and segmented mirror systems needed to enable both general astrophysics and ultra-high contrast observations of exoplanets missions as a function of potential launch vehicle and its inherent mass and volume constraints. We defined and initiated a program to mature 6 key technologies required to fabricate monolithic and segmented space mirrors.

Stahl, H. Philip↗

NASA NTRS1978

Design and fabrication of a radiative actively cooled honeycomb sandwich panel

The mass of a radiative actively cooled panel was compared to the mass of a bare actively cooled panel designed to the same conditions and constraints. The approach was to design and optimize a 0.61 x 6.1 m full scale panel which combines radiative and active cooling to control structural temperatures to levels compatible with use of lightweight materials and to fabricate a 0.61 x 1.22 m panel for performance testing. Results of the design and optimization of the full scale radiative actively cooled structural panel, including radiative concept selection, final configuration details, test panel description, and conclusions are summarized.

Koch, L. C.↗

NASA NTRS1973

Gas-lubricated foil bearings for high speed turboalternator - Construction and performance

Foil bearings were designed and fabricated to replace pivoted-shoe journal bearings in a Brayton cycle turboalternator, within space limitations and constraints imposed by the existing machine. The foil bearings were integrated into a unified assembly with the rotor, housing, seals, and gimbal-mounted thrust bearing, without changes and modifications of machine components other than the journal bearings. The gas-lubricated foil bearings, which require no external pressure-source, furnished a stable support for a 21.9 pound rotor in the vertical attitude at speeds to 43,200 rpm. Excellent wipe-wear characteristics permitted well over 1000 start-stop cycles, without deterioration of performance in the entire speed range. The paper reviews salient aspects of design, fabrication, and performance. An account is given of rotor dynamics during starting, stopping, and traversing the region of resonances. The state of journal and foil surfaces is examined following intensive start-stop cycling and high-speed runs over extended periods of time.

Licht, L.↗

NASA NTRS1980

A J-band space-fed phased array

A J-band, space-fed transmissive array suitable to the constraints of space platform applications has been designed and an engineering model array has been fabricated and tested. Attention is given to the design of the aperture, radiating element, phase shifter module, and flatplate feed. Test results and performance are discussed with reference to gain, sidelobe level, and beamwidth as functions of frequency and scan angle.

Orr, C. L.↗

NASA NTRS1994

A structural fabric defined by topographic lineaments: Correlation with Tertiary deformation of Ellesmere and Axel Heiberg Islands, Canadian Arctic

Digital topographic contours from four 1:250000 scale maps have been gridded to produce a digital elevation model for part of Ellesmere and Axel Heiberg islands in the Canadian Arctic Islands. Gradient calculations were used to define both east and west dipping slopes defining a pattern of lineaments that have been compared with mapped geological structures. In ice-covered areas, where geological mapping was not possible, well-defined topographic lineaments have been identified and are correlated to extensions of major structural features. The northeast-southwest patterns of both topographic lineaments and mapped structures are strongly unimodal and support a single compressive event oriented at 67 deg west of north. This orientation is coincidental with the convergence direction calculated from the kinematic poles of rotation for Greenland relative to North America between 56 and 35 Ma. A minor secondary peak at 70 east of north is observed for thrust and normal fault solutions and is not directly related to the predicted convergence direction. Whether this represents a unique phase of deformation or is a subcomponent of a single event is not known. The agreement of structural components, lineament orientations, and convergence direction suggests an overwhelming over print of Eurekan deformation on any preexisting structural fabric. This study confirms, for the first time, an excellent compatibility between geological and geophysical constraints for the timing and geometry of the Eurekan orogeny.

Oakey, Gordon↗

NASA NTRS2011

Simulation and Optimization of Vacuum Swing Adsorption Units for Spacesuit Carbon Dioxide and Humidity Control

Controlling carbon dioxide (CO2) and humidity levels in a spacesuit is critical to ensuring both the safety and comfort of an astronaut during extra-vehicular activity (EVA). Traditionally, this has been accomplished utilizing either non-regenerative lithium hydroxide (LiOH) or regenerative but heavy metal oxide (MetOx) canisters which pose a significant weight burden. Although such technology enables air revitalization, the volume requirements to store the waste canisters as well as the mass to transport multiple units become prohibitive as mission durations increase. Consequently, motivation exists toward developing a fully regenerative technology for spacesuit environmental control. The application of solid amine materials with vacuum swing adsorption technology has shown the capacity to control CO2 while concomitantly managing humidity levels through a fully regenerative cycle eliminating constraints imposed with the traditional technologies. Prototype air revitalization units employing this technology have been fabricated in both a rectangular and cylindrical geometry. Experimental results for these test articles have been collected and are described herein. In order to accelerate the developmental efforts, an axially-dispersed plug flow model with an accompanying energy balance has been established and correlated with the experimental data. The experimental and simulation results display good agreement for a variety of flow rates (110-170 ALM), replicated metabolic challenges (100-590 Watts), and atmosphere pressures under consideration for the spacesuit (248 and 760 mm Hg). The testing and model results lend insight into the operational capabilities of these devices as well as the influence the geometry of the device has on performance. In addition, variable metabolic profiles were imposed on the test articles in order to assess the ability of the technology to transition to new metabolic conditions. The advent of the model provides the capacity to apply computer-aided engineering practices to support the ongoing efforts to optimize and mature this technology for future application to space exploration.

Swickrath, Michael J.↗

NASA NTRS2014

Toward Large-Area Sub-Arcsecond X-Ray Telescopes

The future of x-ray astronomy depends upon development of x-ray telescopes with larger aperture areas (>1 sq m) and finer angular resolution(<1).Combined with the special requirements of nested grazing incidence optics, the mass and envelope constraints of spaceborne telescopes render such advances technologically challenging. Achieving this goal will require precision fabrication, alignment, mounting, and assembly of large areas (>100 sq m) of lightweight (1 kg/sq m areal density) high quality mirrors-possibly entailing active (in-space adjustable) alignment and figure correction. This paper discusses relevant programmatic and technological issues and summarizes progress toward large area sub-arcsecond x-ray telescopes. Key words: X-ray telescopes, x-ray optics, active optics, electroactive devices, silicon mirrors, differential deposition, ion implantation.

O'Dell, Stephen L.↗

NASA NTRS1975

Computer aided flexible envelope designs

Computer aided design methods are presented for the design and construction of strong, lightweight structures which require complex and precise geometric definition. The first, flexible structures, is a unique system of modeling folded plate structures and space frames. It is possible to continuously vary the geometry of a space frame to produce large, clear spans with curvature. The second method deals with developable surfaces, where both folding and bending are explored with the observed constraint of available building materials, and what minimal distortion result in maximum design capability. Alternative inexpensive fabrication techniques are being developed to achieve computer defined enclosures which are extremely lightweight and mathematically highly precise.

Resch, R. D.↗

NASA NTRSDate not supplied

Fine Optimization of TES Design for the X-IFU Instrument on ATHENA

The X-ray Integral Field Unit (X-IFU) instrument on the Advanced Telescope for High ENergy Astrophysics (ATHENA) is baselined to have 3168 transition-edge sensor (TES) microcalorimeter pixels. These pixels will be DC biased and readout using time division multiplexing. We recently reported a demonstration of the required pixel and readout performance in 252 pixels from a 1 kilo-pixel array (e.g. 2.16 eV resolution for 6.9 keV X-rays). Having achieved the required performance, the 50um square TES design in this demonstration array is considered the baseline pixel design for X-IFU. However, by making small adjustments to the TES design, we may be able to make small but consequential improvements to the instrument performance, while staying within the many constraints of the X-IFU requirements. In this presentation, we will show results from newly fabricated devices with subtle changes from the baseline TES design to further optimize the performance for X-IFU. We will discuss optimizing the TES sheet resistance, normal metal features, X-ray absorber attachment points, TES aspect ratio, and heat capacity. These minor design changes can have significant effects on thermo-electric time constants, thermal fluctuation noise, resistive transition shape and uniformity, and non-linearity of X-ray event pulses. In addition, full characterization of these new TES designs allows greater understanding of the relevant physics within the TES and gives routes for further optimization.

Nick Wakeham↗

NASA NTRS2008

All-Organic Actuator Fabricated with Single Wall Carbon Nanotube Electrodes

Compliant electrodes to replace conventional metal electrodes have been required for many actuators to relieve the constraint on the electroactive layer. Many conducting polymers have been proposed for the alternative electrodes, but they still have a problem of poor thermal stability. This article reports a novel all-organic actuator with single wall carbon nanotube (SWCNT) films as the alternative electrode. The SWCNT film was obtained by filtering a SWCNT solution through an anodized alumina membrane. The conductivity of the SWCNT film was about 280 S/cm. The performance of the SWCNT film electrode was characterized by measuring the dielectric properties of NASA Langley Research Center - Electroactive Polymer (LaRC-EAP) sandwiched by the SWCNT electrodes over a broad range of temperature (from 25 C to 280 C) and frequency (from 1 KHz to 1 MHz). The all-organic actuator with the SWCNT electrodes showed a larger electric field-induced strain than that with metal electrodes, under identical measurement conditions.

Lowther, Sharon E.↗

NASA NTRS1972

Design criteria monograph on turbopump inducers

State of the art and design criteria for liquid rocket engine turbopump inducers are summarized for optimal fabrication. Design criteria optimize hydrodynamic parameters to obtain highest suction specific speed without violating structural and mechanical constraints.

Source record↗

NASA NTRS1979

Behavior of composite bolted joints at elevated temperature

Experimental results from an investigation which examines the combined effects of temperature, joint geometry and out-of-plane constraint upon the response of mechanically fastened composite joints are presented. Data are presented for simulated mechanically fastened joint conditions in two laminate configurations fabricated from Hercules AS/3501-6 graphite-epoxy. Strength and failure mode results are presented for the test temperatures of 21 C, 121 C and 177 C and for a range of the geometric parameters W/D and e/D from 3.71 to 7.43 and 1.85 to 3.69, respectively. A hole diameter, D of 5.16 mm was utilized for all tests. Pin bearing tests with out-of-plane constraint were conducted at room temperature only. All elevated temperature data were generated for pin bearing conditions. Ultrasonic C scan inspection of the failed specimens was employed to assess the damage region and to determine failure mode. Comparative data are presented for pin bearing and out-of-plane constraint conditions for the above mentioned joint configurations. The joint under pin loading was modeled by two dimensional finite element methods. Predicted net section strain concentrations were compared with experimental results.

Wilson, D. W.↗

NASA NTRS1980

Shuttle considerations for the design of large space structures

Shuttle related considerations (constraints and guidelines) are compiled for use by designers of a potential class of large space structures which are transported to orbit and, deployed, fabricated or assembled in space using the Space Shuttle Orbiter. Considerations of all phases of shuttle operations from launch to ground turnaround operations are presented. Design of large space structures includes design of special construction fixtures and support equipment, special stowage cradles or pallets, special checkout maintenance, and monitoring equipment, and planning for packaging into the orbiter of all additional provisions and supplies chargeable to payload. Checklists of design issues, Shuttle capabilities constraints and guidelines, as well as general explanatory material and references to source documents are included.

Roebuck, J. A., Jr.↗

NASA NTRS2014

Toward Large-Area Sub-Arcsecond X-Ray Telescopes

The future of x-ray astronomy depends upon development of x-ray telescopes with larger aperture areas (approx. = 3 square meters) and fine angular resolution (approx. = 1 inch). Combined with the special requirements of nested grazing-incidence optics, the mass and envelope constraints of space-borne telescopes render such advances technologically and programmatically challenging. Achieving this goal will require precision fabrication, alignment, mounting, and assembly of large areas (approx. = 600 square meters) of lightweight (approx. = 1 kilogram/square meter areal density) high-quality mirrors at an acceptable cost (approx. = 1 million dollars/square meter of mirror surface area). This paper reviews relevant technological and programmatic issues, as well as possible approaches for addressing these issues-including active (in-space adjustable) alignment and figure correction.

ODell, Stephen L.↗

NASA NTRS2023

2022 Research & Technology Report

The 2022 Research and Technology Annual Report represents what is hopefully the “new normal” for portfolio execution. The portfolio took advantage of the best features of the virtual work environment with collaborations across the nation without any geographical constraints. This allowed key partnerships between NASA Marshall Space Flight Center (MSFC) and other NASA centers, other government agencies, industry, and academia. Also, because there were no longer any constraints on laboratory and test capabilities, we were able to make significant progress with hands-on technology development, fabrication and testing that is critical to validating the efficacy of advanced technology.

J. W. Dankanich↗

NASA NTRS1990

A unique approach to space thermal simulation

The Space Systems Lab of McDonnell Douglas developed several innovative techniques to perform the DELTA Star System thermal vacuum test. Test design constraints included an accelerated test schedule and an ambitious test plan focusing on cyclic absorbed orbital flux simulation. Test design and fabrication was completed in only 4 months, producing a 21 zone computer modeled refectorless lamp array system. Array zone control was based on discreet absorbed flux measurements, provided by adiabatic coupons conceived to eliminate the need for conventional radiometers. Test requirements, methodology, and test thermal model flight data correlation are presented.

Durant, D. Q.↗

NASA NTRS2017

Development and Testing of a Novel Green Propellant Piston Tank

Analytical Mechanics Associates (AMA), in cooperation with NASA Marshall Space Flight Center's (MSFC's) Spacecraft Propulsion Systems Branch, developed and tested a novel propellant tank design that employs an internal piston pressurized with an inert gas to expel propellant to thrusters. During the course of this activity, AMA designed, oversaw fabrication, and delivered to MSFC for testing, a piston propellant tank sized for 3U or larger CubeSats. MSFC conducted liquid expulsion testing using ethylene glycol as a referee fluid to map the tank's performance at different pressures and piston positions. Following the expulsion test campaign, the tank is planned to be integrated into a propulsion system test bed for hot fire tests with a 100mN monopropellant thruster to evaluate the tank's influence on thruster performance when operated in a flight like manner. Described in this paper is a comprehensive summary of how the tanks were designed, built, and tested. The fundamental knowledge gained through the fabrication and testing of these tanks gives evidence that the piston tank design may be scalable to meet the requirements and constraints of other small satellites.

Diaz, C. E.↗