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

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At least 109 records · Page 6
All sourcesNASA NTRSDOE OSTI
NASA NTRS2002

STS-112/Atlantis/ISS 9A Pre-Launch - Launch On-Orbit - Landing - Crew Egress

The video starts with an introduction of the crew of Space Shuttle Atlantis on STS-112 at their customary pre-flight meal. The crew consists of Commander Jeffrey Ashby, Pilot Pam Melroy, and Mission Specialists David Wolf, Sandra Magnus, Piers Sellers, and Fyodor Yurchikhin. The crew is then shown during suit-up, while exiting the Operations and Checkout Building to board the Astrovan, and during ingress and seating. Launch views include: Beach Tracker, VAB, PAD-B, Tower-1, DLTR-3, Grandstand, Cocoa Beach DOAMS, Playalinda DOAMS, UCS-23, OTV-170, OTV-171, and External Tank Camera. On-orbit footage includes the Atlantis orbiter docking with the ISS (International Space Station). The video shows clips of extravehicluar activities (EVAs), and some of the tasks performed during the mission. Footage included shows the installation of the S1 Truss onto the ISS with the Space Station Remote Manipulator System (Canadarm 2), Canadarm 2 carrying the Ammonia Tank Assembly prior to connection, the checkout of the Thermal Radiator Rotary Joint, the soft docking of an S-Band antenna, and the deployment of the S1 Radiator. An onboard repair of the ISS humidity separator is also shown. Landing views include: VAB, Tower 1, Mid-Field, Runway South End, Runway North End, Tower-2, Cocoa Beach DOAMS, and PPOV. Kennedy Space Center managers greet the crew upon arrival, and Commander Ashby gives a brief speech while standing with his crew members.

Source record↗
NASA NTRS2003

Institute for Advanced Education in Geospatial Sciences Educating the Next Generation of Scientists

The project, as stated earlier is sponsored by NASA and is located at the University of Mississippi in Oxford, MS. It has two principal investigators with one of them, Pam Lawhead, serving as the Director of the Institute. The goal of the project is to create fifty online courses in Remote Sensing over the five year life of the project. Each year ten courses are put out for bid and the best ten submissions are accepted. This request for proposals insures that the course creators are content experts. Equivalence of product drives the online hosting of the courses. That is, we want the online presentation and delivery of each course to be as multi-media intensive as is effective. The goal is not to replace existing courses but, to provide courses created by content experts to as many colleges and universities as possible. This effort to create and host online courses has as its final goal the creation of a very large college educated workforce prepared to use the vast stores of information gathers by NASA and other remote sensing industries to enhance life on this planet.

Lawhead, Pamela↗
NASA NTRS2004

Comparison of SPHC Hydrocode Results with Penetration Equations and Results of Other Codes

The SPHC hydrodynamic code was used to simulate impacts of spherical aluminum projectiles on a single-wall aluminum plate and on a generic Whipple shield. Simulations were carried out in two and three dimensions. Projectile speeds ranged from 2 kilometers per second to 10 kilometers per second for the single-wall runs, and from 3 kilometers per second to 40 kilometers per second for the Whipple shield runs. Spallation limit results of the single-wall simulations are compared with predictions from five standard penetration equations, and are shown to fall comfortably within the envelope of these analytical relations. Ballistic limit results of the Whipple shield simulations are compared with results from the AUTODYN-2D and PAM-SHOCK-3D codes presented in a paper at the Hypervelocity Impact Symposium 2000 and the Christiansen formulation of 2003.

Evans, Steven W.↗
NASA NTRS2004

Correlation of Lightning Flash Rates with a Microburst Event

In 1986 the MIST (Microburst and Severe - Thunderstorm) field study took place over northern Alabama. It was noted that the time of day when a peak in microburst activity was observed usually took place around 2000 UTC. It was further confirmed through the examination of the various PAM (Portable Automated Mesonet) stations that this was also the time of day where temperatures would reach their peak. On the afternoon of 18 August 2002, as the temperature approached a daily high temperature of 32 C, the first radar indication of the HSV microburst-producing storm initiated at 2020 UTC.

Altino, Karen M.↗
NASA NTRS2011

Simplified Architecture for Precise Aiming of a Deep-Space Communication Laser Transceiver

The simplified architecture is a minimal system for a deep-space optical communications transceiver. For a deepspace optical communications link the simplest form of the transceiver requires (1) an efficient modulated optical source, (2) a point-ahead mechanism (PAM) to compensate for two-way light travel, (3) an aperture to reduce the divergence of the transmit laser communication signal and also to collect the uplink communication signal, and (4) a receive detector to sense the uplink communication signal. Additional components are introduced to mitigate for spacecraft microvibrations and to improve the pointing accuracy. The Canonical Transceiver implements this simplified architecture (see figure). A single photon-counting smart focal plane sensor combines acquisition, tracking, and forward link data detection functionality. This improves optical efficiency by eliminating channel splits. A transmit laser blind sensor (e.g. silicon with 1,550-nm beam) provides transmit beam-pointing feedback via the two-photon absorption (TPA) process. This vastly improves the transmit/receive isolation because only the focused transmit beam is detected. A piezoelectric tiptilt actuator implements the required point-ahead angle. This point-ahead mechanism has been demonstrated to have near zero quiescent power and is flight qualified. This architecture also uses an innovative 100-mHz resonant frequency passive isolation platform to filter spacecraft vibrations with voice coil actuators for active tip-tilt correction below the resonant frequency. The canonical deep-space optical communications transceiver makes synergistic use of innovative technologies to reduce size, weight, power, and cost. This optical transceiver can be used to retire risks associated with deep-space optical communications on a planetary pathfinder mission and is complementary to ongoing lunar and access link developments.

Ortiz, Gerard G.↗
NASA NTRS2004

Iterative Demodulation and Decoding of Non-Square QAM

It has been shown that a non-square (NS) 2(sup 2n+1)-ary (where n is a positive integer) quadrature amplitude modulation [(NS)2(sup 2n+1)-QAM] has inherent memory that can be exploited to obtain coding gains. Moreover, it should not be necessary to build new hardware to realize these gains. The present scheme is a product of theoretical calculations directed toward reducing the computational complexity of decoding coded 2(sup 2n+1)-QAM. In the general case of 2(sup 2n+1)-QAM, the signal constellation is not square and it is impossible to have independent in-phase (I) and quadrature-phase (Q) mapping and demapping. However, independent I and Q mapping and demapping are desirable for reducing the complexity of computing the log likelihood ratio (LLR) between a bit and a received symbol (such computations are essential operations in iterative decoding). This is because in modulation schemes that include independent I and Q mapping and demapping, each bit of a signal point is involved in only one-dimensional mapping and demapping. As a result, the computation of the LLR is equivalent to that of a one-dimensional pulse amplitude modulation (PAM) system. Therefore, it is desirable to find a signal constellation that enables independent I and Q mapping and demapping for 2(sup 2n+1)-QAM.

Li, Lifang↗
NASA NTRS2013

Environmental Monitoring of Microbe Metabolic Transformation

Mobile system and method for monitoring environmental parameters involved in growth or metabolic transformation of algae in a liquid. Each of one or more mobile apparati, suspended or partly or wholly submerged in the liquid, includes at least first and second environmental sensors that sense and transmit distinct first and second environmental, growth or transformation parameter values, such as liquid temperature, temperature of gas adjacent to and above the exposed surface, liquid pH, liquid salinity, liquid turbidity, O.sub.2 dissolved in the liquid, CO.sub.2 contained in the liquid, oxidization and reduction potential of the liquid, nutrient concentrations in the liquid, nitrate concentration in the liquid, ammonium concentration in the liquid, bicarbonate concentration in the liquid, phosphate concentration in the liquid, light intensity at the liquid surface, electrical conductivity of the liquid, and a parameter.alpha.(alga) associated with growth stage of the alga, using PAM fluorometry or other suitable parameter measurements.

Bebout, Brad↗
NASA NTRS2018

Ground-Based Measurements and Validation Protocols for Flex

The upcoming ESA Fluorescence Explorer (FLEX) mission will incorporate ground-based validations for fluorescence parameters and reflectance indices, drawing on an international network of sensors located at eddy covariance tower sites. A program has been initiated by the OPTIMISE program to develop methods and protocols for this network. A sensor system suite under evaluation by OPTIMISE includes the FLoX hyperspectral spectroradiometers. The NASA team at GSFC is participating in this experiment and we report first results from the 2017 summer measurements made above the canopy at the USDA/ARS Beltsville cornfield using the DFLoX and two other leaf-level measurement systems, the MONI-PAM and the FluoWat.

DFLOX↗
NASA NTRS2019

Persistent Assets in Zero-G and on Planetary Surfaces: Enabled by Modular Technology and Robotic Operations

Space operations are on the cusp of a revolutionary new operational paradigm that leverages modular systems and recurring robotic visits to “Persistent Assets” enabling asset maintenance, repair, and enhancement. A “Persistent Asset” is defined here as any zero-g or planetary surface system that benefits from in-space assembly (ISA) or multiple visits for servicing, repairs, and upgrades. This term is an extension of the term “Persistent Platform” used by Ms. Pam Melroy at the Defense Advanced Research Projects Agency to describe the vision of the Agency for a geosynchronous Earth orbiting platform. In this paper, the term “Persistent Asset” is introduced to encompass not only zero-g systems; such as telecommunication platforms, Earth observing science platform, Department of Defense platforms, and scientific telescope systems, but also planetary surface systems that support missions such as human outposts, science stations, and in-situ resource utilization systems. In contrast to the current state of the art, where space systems are typically launched as a single unit and operated without any further physical intervention after launch; future systems will be maintained, enhanced and reconfigured in-situ as new technology becomes available or mission needs change. Visits to the persistent asset can be regularly scheduled or dictated by funding constraints enabling a pay-as-you-go approach, which is largely independent of time-constraints and able to exploit launches of opportunity. In this paper, historical in-space assembly activities which relied heavily on astronaut extra-vehicular activity will be reviewed as well as early robotic assembly activities. These approaches will be contrasted with emerging modular approaches supporting realization of a new Persistent Asset operational paradigm. The paper will define attributes of the Persistent Asset paradigm and illustrate advantages by applying the paradigm to two relevant applications: 1) a large space telescope backing structure and 2) the backbone structure for a solar electric transport vehicle. Finally, recently developed unique Persistent Asset elements (modules, and interface approaches) will be described.

Doggett, William R.↗
NASA NTRS2018

Persistent Assets in Zero-G and on Planetary Surfaces: Enabled by Modular Technology and Robotic Operations

Space operations are on the cusp of a revolutionary new operational paradigm that leverages modular systems and recurring robotic visits to “Persistent Assets” enabling asset maintenance, repair, and enhancement. A “Persistent Asset” is defined here as any zero-g or planetary surface system that benefits from in-space assembly (ISA) or multiple visits for servicing, repairs, and upgrades. This term is an extension of the term “Persistent Platform” used by Ms. Pam Melroy at the Defense Advanced Research Projects Agency to describe the vision of the Agency for a geosynchronous Earth orbiting platform. In this paper, the term “Persistent Asset” is introduced to encompass not only zero-g systems; such as telecommunication platforms, Earth observing science platform, Department of Defense platforms, and scientific telescope systems, but also planetary surface systems that support missions such as human outposts, science stations, and in-situ resource utilization systems. In contrast to the current state of the art, where space systems are typically launched as a single unit and operated without any further physical intervention after launch; future systems will be maintained, enhanced and reconfigured in-situ as new technology becomes available or mission needs change. Visits to the persistent asset can be regularly scheduled or dictated by funding constraints enabling a pay-as-you-go approach, which is largely independent of time-constraints and able to exploit launches of opportunity. In this paper, historical in-space assembly activities which relied heavily on astronaut extra-vehicular activity will be reviewed as well as early robotic assembly activities. These approaches will be contrasted with emerging modular approaches supporting realization of a new Persistent Asset operational paradigm. The paper will define attributes of the Persistent Asset paradigm and illustrate advantages by applying the paradigm to two relevant applications: 1) a large space telescope backing structure and 2) the backbone structure for a solar electric transport vehicle. Finally, recently developed unique Persistent Asset elements (modules, and interface approaches) will be described.

William R Doggett↗
NASA NTRS2021

Scaling photosynthetic function and CO2 dynamics from leaf to canopy level for maize – dataset combining diurnal and seasonal measurements of vegetation fluorescence, reflectance and vegetation indices with canopy gross ecosystem productivity

Recent advances in leaf fluorescence measurements and canopy proximal remote sensing currently enable the non-destructive collection of rich diurnal and seasonal time series, which are required for monitoring vegetation function at the temporal and spatial scales relevant to the natural dynamics of photosynthesis. Remote sensing assessments of vegetation function have traditionally used actively excited foliar chlorophyll fluorescence measurements, canopy optical reflectance data and vegetation indices (VIs), and only recently passive solar induced chlorophyll fluorescence (SIF) measurements. In general, reflectance data are more sensitive to the seasonal variations in canopy chlorophyll content and foliar biomass, while fluorescence observations more closely relate to the dynamic changes in plant photosynthetic function. With this dataset we link leaf level actively excited chlorophyll fluorescence, canopy proximal reflectance and SIF, with eddy covariance measurements of gross ecosystem productivity (GEP). The dataset was collected during the 2017 growing season on maize, using three automated systems (i.e., Monitoring Pulse-Amplitude-Modulation fluorimeter, Moni-PAM; Fluorescence Box, FloX; and from eddy covariance tower). The data were quality checked, filtered and collated to a common 30 minutes timestep. We derived vegetation indices related to canopy functioning (e.g., Photochemical Reflectance Index, PRI; Normalized Difference Vegetation Index, NDVI; Chlorophyll Red-edge, Clre) to investigate how SIF and VIs can be coupled for monitoring vegetation photosynthesis. The raw datasets and the filtered and collated data are provided to enable new processing and analyses.

Petya Campbell↗
NASA NTRS1987

Design and test of an NLF wing glove for the variable-sweep transition flight experiment

Gloves for M = 0.7 and 0.8 design points were computationally designed and analyzed at conditions over the proposed flight test envelope. The resulting computational pressure distributions were analyzed in a boundary layer stability code. These results indicate that the available pressure distributions offer a wide range of combinations of cross flow and Tollmien-Schlichting N-factors. The glove designs along with the baseline configuration were tested in an entry into the National Transonic Facility. Analysis of the force and moment data showed no significant differences in the performance and stability and control characteristics between the baseline and gloved configurations. The rolling moment constraint was met over the entire flight test envelope for the gloved configuration. Pressure distributions for the NTF test confirmed the design pressure distributions were achieved. However, it was decided that with minor modifications to the inboard region of the glove, useful available data could be significantly increased by adding another row of pressure orifices at span station 167.

Waggoner, Ed G.↗
NASA NTRS1991

Aberration corrected aspheric grating for far ultraviolet spectrographs - Conventional approach

Two approaches to reducing optical aberrations of concave grating spectrographs have been used, holographically controlling the groove curvature and spacing and reshaping the optical substrate while ruling the grooves conventionally. The latter approach, slightly deforming an ellipsoidal grating blank, can lead to diffraction-limited performance at a single FUV wavelength. When such a grating is used in a slitted Rowland circle spectrograph, the result is an extremely efficient spectrograph with spectral resolving power of about 30,000 and low astigmatism. Optical fabrication technology has advanced to the point where these exotic surface gratings are becoming practical.

Content, David↗
NASA NTRS1992

Panel Library And Editor

Panel Library and Editor computer program is grapical-user-interface builder program for use on workstations of Silicon Graphics IRIS family. Program creates "widgets" manipulated by user. Appearance similar to X-Windows System. Used by programmers to write user-friendly mouse-driven application programs for IRIS workstations. Panel Library (v9.8) and Editor (v1.1) written in C Language and Scheme.

Raible, Eric↗
NASA NTRS1992

Protein crystal growth aboard the U.S. Space Shuttle flights STS-31 and STS-32

Results obtained from the Shuttle flight STS-32 flown in January 1990, and preliminary results from the most recent Shuttle flight, STS-31, flown in April 1990, are presented. Crystals grown in microgravity environment include Canavalin, isocitrate lyase, human serum albumin, and Anti-HPr Fab. It is concluded that about 20 percent of proteins flown exhibit better morphologies or better quality data than their earth-grown counterparts. About 40 percent do not yield crystals at all and the remaining 40 percent yield crystals that are either too small for X-ray analysis or produce data of poorer quality than the best earth-grown crystals.

Delucas, Lawrence J.↗
NASA NTRS1992

Aberration-corrected aspheric grating designs for the Lyman/Far-Ultraviolet Spectroscopic Explorer high-resolution spectrograph - A comparison

Two approaches to reducing the optical aberrations of concave diffraction gratings have been studied to obtain candidate grating designs for the Lyman/Far-Ultraviolet Spectroscopic Explorer mission. The first approach involves shaping the grating substrate while using straight and equally spaced grooves. The second approach involves using a gating substrate with a relatively simple figure and holographically controlling the groove curvature and spacing. Specific designs derived from both approaches are analyzed and compared.

Trout, Catherine↗
NASA NTRS1993

Flow Analysis Software Toolkit

Flow Analysis Software Toolkit (FAST) computer program provides software environment facilitating visualization of data. Collection of separate programs (modules) running simultaneously and helps user to examine results of numerical and experimental simulations. Intended for graphical depiction of computed flows, also assists in analysis of other types of data. Combines capabilities of such programs as PLOT3D, RIP, SURF, and GAS into one software environment with modules sharing data. All modules have consistent, highly interactive graphical user interface. Modular construction makes it flexible and extensible. Environment custom-configured, and new modules developed and added as needed. Written in ANSI compliant FORTRAN 77 and C language.

Watson, Velvin↗