SEARCH · Engineering Papers

Results for “block design”

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.

SourceResearch connectionFrom yearThrough year

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 127 records · Page 7

All sources NASA NTRS DOE OSTI

NASA NTRS2012

Blocking Filters with Enhanced Throughput for X-Ray Microcalorimetry

New and improved blocking filters (see figure) have been developed for microcalorimeters on several mission payloads, made of high-transmission polyimide support mesh, that can replace the nickel mesh used in previous blocking filter flight designs. To realize the resolution and signal sensitivity of today s x-ray microcalorimeters, significant improvements in the blocking filter stack are needed. Using high-transmission polyimide support mesh, it is possible to improve overall throughput on a typical microcalorimeter such as Suzaku s X-ray Spectrometer by 11%, compared to previous flight designs. Using polyimide to replace standard metal mesh means the mesh will be transparent to energies 3 keV and higher. Incorporating polyimide s advantageous strength-to-weight ratio, thermal stability, and transmission characteristics permits thinner filter materials, significantly enhancing through - put. A prototype contamination blocking filter for ASTRO-H has passed QT-level acoustic testing. Resistive traces can also be incorporated to provide decontamination capability to actively restore filter performance in orbit.

Grove, David↗

NASA NTRS1984

Assessment of Thematic Mapper Band-to-band Registration by the Block Correlation Method

The design of the Thematic Mapper (TM) multispectral radiometer makes it susceptible to band-to-band misregistration. To estimate band-to-band misregistration a block correlation method is employed. This method is chosen over other possible techniques (band differencing and flickering) because quantitative results are produced. The method correlates rectangular blocks of pixels from one band against blocks centered on identical pixels from a second band. The block pairs are shifted in pixel increments both vertically and horizontally with respect to each other and the correlation coefficient for each shift position is computed. The displacement corresponding to the maximum correlation is taken as the best estimate of registration error for each block pair. Subpixel shifts are estimated by a bi-quadratic interpolation of the correlation values surrounding the maximum correlation. To obtain statistical summaries for each band combination post processing of the block correlation results performed. The method results in estimates of registration error that are consistent with expectations.

Card, D. H.↗

NASA NTRS1994

STS-60 Space Shuttle mission report

The STS-60 Space Shuttle Program Mission Report summarizes the Payload activities as well as the Orbiter, External Tank (ET), Solid Rocket Booster (SRB), Redesigned Solid Rocket Motor (RSRM), and the Space Shuttle main engine (SSME) systems performance during the sixtieth flight of the Space Shuttle Program and eighteenth flight of the Orbiter vehicle Discovery (OV-103). In addition to the Orbiter, the flight vehicle consisted of an ET designated at ET-61 (Block 10); three SSME's which were designated as serial numbers 2012, 2034, and 2032 in positions 1, 2, and 3, respectively; and two SRB's which were designated BI-062. The RSRM's that were installed in each SRB were designated as 360L035A (lightweight) for the left SRB, and 360Q035B (quarterweight) for the right SRB. This STS-60 Space Shuttle Program Mission Report fulfills the Space Shuttle Program requirement as documented in NSTS 07700, Volume VIII, Appendix E. That document requires that each major organizational element supporting the Program report the results of its hardware evaluation and mission performance plus identify all related in-flight anomalies. The primary objectives of the STS-60 mission were to deploy and retrieve the Wake Shield Facility-1 (WSF-1), and to activate the Spacehab-2 payload and perform on-orbit experiments. Secondary objectives of this flight were to activate and command the Capillary Pumped Loop/Orbital Debris Radar Calibration Spheres/Breman Satellite Experiment/Getaway Special (GAS) Bridge Assembly (CAPL/ODERACS/BREMSAT/GBA) payload, the Auroral Photography Experiment-B (APE-B), and the Shuttle Amateur Radio Experiment-II (SAREX-II).

Fricke, Robert W., Jr.↗

NASA NTRS2002

Software Development for the Hobby-Eberly Telescope's Segment Alignment Maintenance System using LABView

The software development for an upgrade to the Hobby-Eberly Telescope (HET) was done in LABView. In order to improve the performance of the HET at the McDonald Observatory, a closed-loop system had to be implemented to keep the mirror segments aligned during periods of observation. The control system, called the Segment Alignment Maintenance System (SAMs), utilized inductive sensors to measure the relative motions of the mirror segments. Software was developed in LABView to tie the sensors, operator interface, and mirror-control motors together. Developing the software in LABView allowed the system to be flexible, understandable, and able to be modified by the end users. Since LABView is built using block diagrams, the software naturally followed the designed control system's block and flow diagrams, and individual software blocks could be easily verified. LABView's many built-in display routines allowed easy visualization of diagnostic and health-monitoring data during testing. Also, since LABView is a multi-platform software package, different programmers could develop the code remotely on various types of machines. LABView s ease of use facilitated rapid prototyping and field testing. There were some unanticipated difficulties in the software development, but the use of LABView as the software "language" for the development of SAMs contributed to the overall success of the project.

Hall, Drew P.↗

NASA NTRS2014

Optical Design for a Survey X-Ray Telescope

Optical design trades are underway at the Goddard Space Flight Center to define a telescope for an x-ray survey mission. Top-level science objectives of the mission include the study of x-ray transients, surveying and long-term monitoring of compact objects in nearby galaxies, as well as both deep and wide-field x-ray surveys. In this paper we consider Wolter, Wolter-Schwarzschild, and modified Wolter-Schwarzschild telescope designs as basic building blocks for the tightly nested survey telescope. Design principles and dominating aberrations of individual telescopes and nested telescopes are discussed and we compare the off-axis optical performance at 1.0 KeV and 4.0 KeV across a 1.0-degree full field-of-view.

Design Analysis↗

NASA NTRS1985

Block 5 documentation and solar modules

Design and fabrication of Spire Corporation's Block 5 photovoltaic flat plate module is reviewed. These modules exhibited power of about 70 watts under standard test conditions. Results of performance and environmental testing are provided.

Source record↗

NASA NTRS1993

Synthesis algorithm of VLSI multipliers for ASIC

Multipliers are critical sub-blocks in ASIC design, especially for digital signal processing and communications applications. A flexible multiplier synthesis tool is developed which is capable of generating multiplier blocks for word size in the range of 4 to 256 bits. A comparison of existing multiplier algorithms is made in terms of speed, silicon area, and suitability for automated synthesis and verification of its VLSI implementation. The algorithm divides the range of supported word sizes into sub-ranges and provides each sub-range with a specific multiplier architecture for optimal speed and area. The algorithm of the synthesis tool and the multiplier architectures are presented. Circuit implementation and the automated synthesis methodology are discussed.

Chua, O. H.↗

NASA NTRS2008

Split-Block Waveguide Polarization Twist for 220 to 325 GHz

A split-block waveguide circuit that rotates polarization by 90 has been designed with WR-3 input and output waveguides, which are rectangular waveguides used for a nominal frequency range of 220 to 325 GHz. Heretofore, twisted rectangular waveguides equipped with flanges at the input and output have been the standard means of rotating the polarizations of guided microwave signals. However, the fabrication and assembly of such components become difficult at high frequency due to decreasing wavelength, such that twisted rectangular waveguides become impractical at frequencies above a few hundred gigahertz. Conventional twisted rectangular waveguides are also not amenable to integration into highly miniaturized subassemblies of advanced millimeter- and submillimeter-wave detector arrays now undergoing development. In contrast, the present polarization- rotating waveguide can readily be incorporated into complex integrated waveguide circuits such as miniaturized detector arrays fabricated by either conventional end milling of metal blocks or by deep reactive ion etching of silicon blocks. Moreover, the present split-block design can be scaled up in frequency to at least 5 THz. The main step in fabricating a splitblock polarization-rotating waveguide of the present design is to cut channels having special asymmetrically shaped steps into mating upper and lower blocks (see Figure 1). The dimensions of the steps are chosen to be consistent with the WR-3 waveguide cross section, which is 0.864 by 0.432 mm. The channels are characterized by varying widths with constant depths of 0.432, 0.324, and 0.216 mm and by relatively large corner radii to facilitate fabrication. The steps effect both a geometric transition and the corresponding impedance-matched electromagnetic-polarization transition between (1) a WR-3 rectangular waveguide oriented with the electric field vector normal to the block mating surfaces and (2) a corresponding WR-3 waveguide oriented with its electric field vector parallel to the mating surfaces of the blocks. A prototype has been built and tested. Figure 2 presents test results indicative of good performance over nearly the entire WR-3 waveguide frequency band.

Ward, John↗

NASA NTRS2023

3D Printed Substrate

In preparation for long-term, manned, deep space missions, NASA requires a sustainable system for crop and food production. This system has a variety of benefits, including a fresh food supply, improvements in air quality, a lower need to resupply and psychological benefits for the gardeners. Specifically, NASA is attempting to improve and iterate their Vegetable Production System (VEGGIE), a plant growth unit currently aboard the International Space Station (ISS). The VEGGIE unit is highly dependent on a variety of factors, including passive water delivery, growth lights, rooting pillows and cabin conditions. While previous teams have improved and redesigned water reservoirs, the primary objective of the project was to create a new substrate unit to replace the current rooting pillow design. The current design consists of an electrostatic bag filled with arcillite and a slow-release fertilizer pellet. The prototype design retains the fertilizer pellet for nutrient consistency, however the outer bag and arcillite fillings have been replaced with a 3D printed lattice block. This lattice block has several key points that allow it to function in similar ways to the current design: 1. The lattice planes are porous, with each pore offset such that the overall porosity is the same as the arcillite filling. 2. The block demonstrates a wicking nature and is able to pull water upwards towards the roots. This minimizes time needed to integrate with the existing water reservoir. 3. The filament used is highly flexible and is able to pull apart to accommodate root growth. 4. The lattice planes are connected by microfibers left behind from the printing process. These fibers provide support for the growing roots and keep the lattice planes properly aligned. The substrate block design seeks to reduce the payload costs by being entirely 3D printed. While filament would still need to be provided to the ISS, it is far less expensive than shipping arcillite due to the significantly lower weight. The final design has iterated the lattice plane concept and utilizes vertically placed planes with pores running parallel to the water reservoir. This design has reliably shown water uptake and retention and has been successful in growing multiple romaine lettuce plants. Future work should include further growth testing using multiple plant species, compost and reusability testing, food safety testing and microgravity growth testing.

Affan Bhutta↗

NASA NTRS1993

Embeddable Reconfigurable Neuroprocessors

Reconfigurable and cascadable building block neural network chips, fabricated using analog VLSI design tools, are interfaced to a PC. The building block chip designs, the cascadability and the hardware-in-the-loop supervised learning aspects of these chips are described.

Neuroprocessors↗

NASA NTRS2009

Fabrics Protect Sensitive Skin from UV Rays

Late Johnson Space Center engineer Dr. Robert Dotts headed a team to develop cool suits for children suffering from life-threatening sun sensitivities. Dotts hoped to develop ultraviolet-blocking technology in a fabric that -- unlike in a bulky space suit -- could remain comfortable, light, and breathable in the sun and heat. The team worked with SPF 4 US LLC (SPF) of Madison, Wisconsin to design ultraviolet-blocking cool suits, which protect sun-sensitive patients and enable them to experience life outdoors safely. Using knowledge gained during the NASA collaboration, SPF created an entire line of ultraviolet-blocking apparel.

Source record↗

NASA NTRS2017

Optical Design of the STAR-X Telescope

Top-level science goals of the Survey and Time-domain Astrophysical Research eXplorer (STAR-X) include: investigations of most violent explosions in the universe, study of growth of black holes across cosmic time and mass scale, and measure how structure formation heats majority of baryons in the universe. To meet these goals, the field-of-view of the telescope should be about 1 square-degree, the angular resolution should be 5 arc-seconds or below across large part of the field-of-view. The on-axis effective area at 1 KeV should be about 2,000 sq cm. Payload cost and launch considerations limit the outer diameter, focal length, and mass to 1.3 meters, 5 meters, and 250 kilograms, respectively. Telescope design is based on a segmented meta-shell approach we have developed at Goddard Space Flight Center for the STAR-X telescope. The telescope shells are divided into 30-degree segments. Individual telescopes and meta-shells are nested inside each other to meet the effective area requirements in 0.5 - 6.0 KeV range. We consider Wolter-Schwarzschild, and Modified-Wolter-Schwarzschild telescope designs as basic building blocks of the nested STAR-X telescope. These designs offer an excellent resolution over a large field of views. Nested telescopes are vulnerable to stray light problems. We have designed a multi-component baffle system to eliminate direct and single-reflection light paths inside the telescopes. Large number of internal and external baffle vane structures are required to prevent stray rays from reaching the focal plane. We have developed a simple ray-trace based tool to determine the dimensions and locations of the baffles. In this paper, we present the results of our trade studies, baffle design studies, and optical performance analyses of the STAR-X telescope.

Saha, Timo T.↗

NASA NTRS2017

Design of the STAR-X Telescope

Saha, Timo T.↗

NASA NTRS2017

NASA Collaborative Design Processes

This is Block 1, the first evolution of the world's most powerful and versatile rocket, the Space Launch System, built to return humans to the area around the moon. Eventually, larger and even more powerful and capable configurations will take astronauts and cargo to Mars. On the sides of the rocket are the twin solid rocket boosters that provide more than 75 percent during liftoff and burn for about two minutes, after which they are jettisoned, lightening the load for the rest of the space flight. Four RS-25 main engines provide thrust for the first stage of the rocket. These are the world's most reliable rocket engines. The core stage is the main body of the rocket and houses the fuel for the RS-25 engines, liquid hydrogen and liquid oxygen, and the avionics, or "brain" of the rocket. The core stage is all new and being manufactured at NASA's "rocket factory," Michoud Assembly Facility near New Orleans. The Launch Vehicle Stage Adapter, or LVSA, connects the core stage to the Interim Cryogenic Propulsion Stage. The Interim Cryogenic Propulsion Stage, or ICPS, uses one RL-10 rocket engine and will propel the Orion spacecraft on its deep-space journey after first-stage separation. Finally, the Orion human-rated spacecraft sits atop the massive Saturn V-sized launch vehicle. Managed out of Johnson Space Center in Houston, Orion is the first spacecraft in history capable of taking humans to multiple destinations within deep space. 2) Each element of the SLS utilizes collaborative design processes to achieve the incredible goal of sending human into deep space. Early phases are focused on feasibility and requirements development. Later phases are focused on detailed design, testing, and operations. There are 4 basic phases typically found in each phase of development.

Jones, Davey↗

NASA NTRS1967

Designs of experiments as telescoping sequences of blocks

Telescoping of block sequences in factorial models for searching techniques

Holms, A. G.↗

NASA NTRS1971

Minimal logic block encoder Patent

Encoders designed to generate comma free biorthogonal Reed-Muller type code comprising conversion of 64 6-bit words into 64 32-bit data for communication purposes

Duffy, J. O.↗

NASA NTRS1986

Block 2 Solid Rocket Motor (SRM) conceptual design study, volume 1

Segmented and monolithic Solid Rocket Motor (SRM) design concepts were evaluated with emphasis on joints and seals. Particular attention was directed to eliminating deficiencies in the SRM High Performance Motor (HPM). The selected conceptual design is described and discussed.

Source record↗

NASA NTRSDate not supplied

Validation of Shadowgraph Spectral Analysis using an SLS Block 2 Wind-Tunnel Model

A flow quantification method has previously been developed that uses high-speed shadowgraph images to extract frequency content of a transonic flow field around a wind-tunnel model. In this method, a classical spectral analysis is performed on shadowgraph video pixels to identify their intensity fluctuation frequencies. The spatial change of the image intensity is related to the second derivative of the density gradient. Examining the change of the density gradient as a function of time can be used to understand the flow-field pressure fluctuations. Time-varying pressure measurements collected during a Space Launch System (SLS) unsteady aerodynamic test of an advanced Block 2 booster design are used to calibrate the shadowgraph-based measurements. The test was performed at the NASA Ames Research Center Unitary Plan Wind Tunnel 11- by 11-foot test section and investigated the aerodynamic environment downstream of candidate booster forward attachment hardware geometries of the SLS Block 2 Cargo configuration. Time-correlated shadowgraph video and model surface pressure measurements were acquired during the test and served as an ideal opportunity to calibrate and validate the shadowgraph image intensity method.

Shadowgraph↗