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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 307 records · Page 17
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NASA NTRS2016

Campaign 9 of the K2 Mission: Observational Parameters, Scientific Drivers, and Community Involvement for a Simultaneous Space- and Ground-based Microlensing Survey

K2ʼs Campaign 9 (K2C9) will conduct a approximately 3.7 sq. deg survey toward the Galactic bulge from 2016 April 22 through July 2 that will leverage the spatial separation between K2 and the Earth to facilitate measurement of the microlens parallax Pi(sub E) for approximately greater than 170 microlensing events. These will include several that are planetary in nature as well as many short-timescale microlensing events, which are potentially indicative of free-floating planets (FFPs). These satellite parallax measurements will in turn allow for the direct measurement of the masses of and distances to the lensing systems. In this article we provide an overview of the K2C9 space- and ground-based microlensing survey. Specifically, we detail the demographic questions that can be addressed by this program, including the frequency of FFPs and the Galactic distribution of exoplanets, the observational parameters of K2C9, and the array of resources dedicated to concurrent observations. Finally, we outline the avenues through which the larger community can become involved, and generally encourage participation in K2C9, which constitutes an important pathfinding mission and community exercise in anticipation of WFIRST.

K2s Campaign 9 (K2C9)↗
NASA NTRSDate not supplied

Forging the Forge

As part of the NASA Johnson Space Center’s (JSC) effort to revitalize and recommit to our “Dare Unite Explore” vision for the future, the Center is exploring a new strategy to spread the innovation mindset and increase collaboration across the workforce. In order to maintain JSC’s leadership in human spaceflight, there is a need for working at the speed of commercial industry, breaking down silos between organizations, improving innovation and increasing workforce flexibility. Through brainstorming concepts and benchmarking other facilities, the leadership team evaluated several ideas, assessed constraints and derived that an “Innovation Team” was relatively easy to adopt. Modeled after productive teams like the Jet Propulsion Laboratory’s Innovation Foundry and Glenn Research Center's Compass team, JSC is laying the foundation of a new innovation team called the Forge. This team is as much about getting employees tempered in the ways of innovative thinking as it is about refining design studies and hammering out proposals. By the dictionary definition of the verb, forge can mean either to move ahead slowly and steadily or to move with a sudden increase of speed and power. Driving cultural change in a large government organization like NASA often involves slow perseverance with small injections of momentum to forge ahead. Leveraging lessons learned from the Innovation Foundry and Compass, this paper describes how the collaborative, concurrent engineering framework was tailored to JSC’s needs, as well as the aspects that were considered given JSC’s operation-focused, Program-driven landscape. Our process to drive cultural change, the steps taken, and challenges encountered are discussed. The first two pilots of the teaming framework are described with initial results presented in terms of employee engagement and fostering innovation. We also describe the planned future work and next steps to continue to push the initiative forward. Long has the Center been resting on its operations heritage, now we are forging a new path to Dare to expand frontiers, Unite with our partners and Explore space to benefit humanity.

Culture Change↗
NASA NTRS2023

Transpolar Pc1 Wave Ducting: Swarm, DMSP, and Ground Observations

Alfvén mode Pc1 waves undergo mode conversion to the fast mode due to induced Hall current in the ionosphere. The fast mode Pc1 waves are trapped and propagate across the magnetic field through the ionospheric waveguide. This process is called Pc1 wave ducting (PWD). Ducting is expected to be in any direction, but most of the existing literature investigated only PWDs toward the equator. In this paper, we report the rare observations of PWD propagating from sub-auroral latitudes and pervading the polar cap using Swarm satellites, ground magnetometers, and Defense Meteorological Satellite Program (DMSP) satellites. We first identify the injection region of Pc1 wave where localized broadband transverse waves, isolated aurora, and energetic proton precipitations are concurrently observed. Then, we compare ducting characteristics in the ionosphere between the two hemispheres. For the three events investigated here, PWDs in the Southern Hemisphere (SH) pervaded the polar cap while Pc1 waves in the Northern Hemisphere (NH) did not. This hemispheric asymmetry is attributed to the plasma density in the SH sufficient to form the Pc1 waveguide. However, a sharp plasma density gradient on the propagation path still interrupts the ducting even in higher plasma density (> 10 5 cm -3 ) regions. The observation of two intersecting Swarm satellites indicates the PWD is not only elongated meridionally, but also can have a significant zonal extent beyond that of the injection region.

Hyangpyo Kim↗
NASA NTRS1986

A nonlinear substructuring method for concurrent processing computers

This paper proposes a method, based on substructuring, to solve nonlinear structural analysis problems on multiprocessor computers. Background information is given on the use of substructuring in large-scale finite element programs and computational time distributions for the major components for an example nonlinear finite element analysis are discussed. Implementation of the substructuring method on a typical multiprocessor computer is described and estimates are made of expected reductions in computation times based on nonlinear substructuring results obtained on a single processor computer.

Storaasli, O. O.↗
NASA NTRS1990

Space Transportation Engine Program (STEP), phase B

The Space Transportation Engine Program (STEP) Phase 2 effort includes preliminary design and activities plan preparation that will allow smooth and time transition into a Prototype Phase and then into Phases 3, 4, and 5. A Concurrent Engineering approach using Total Quality Management (TQM) techniques, is being applied to define an oxygen-hydrogen engine. The baseline from Phase 1/1' studies was used as a point of departure for trade studies and analyses. Existing STME system models are being enhanced as more detailed module/component characteristics are determined. Preliminary designs for the open expander, closed expander, and gas generator cycles were prepared, and recommendations for cycle selection made at the Design Concept Review (DCR). As a result of July '90 DCR, and information subsequently supplied to the Technical Review Team, a gas generator cycle was selected. Results of the various Advanced Development Programs (ADP's) for the Advanced Launch Systems (ALS) were contributive to this effort. An active vehicle integration effort is supplying the NASA, Air Force, and vehicle contractors with engine parameters and data, and flowing down appropriate vehicle requirements. Engine design and analysis trade studies are being documented in a data base that was developed and is being used to organize information. To date, seventy four trade studies were input to the data base.

Source record↗
NASA NTRS1992

Development of a hydrogen external burning flight test experiment on the NASA Dryden SR-71A aircraft

A captive-carry flight test experiment of the transonic external burning concept using gaseous hydrogen fuel has ben proposed for the SR-71A flight research test bed aircraft at the NASA Dryden Flight Research Facility, Edwards, California. This program will be the first large-scale, near-field flight test investigation of this base drag reduction technique at Mach numbers up to 3. Low-speed base drag reduction for supersonic and hypersonic flight vehicles is important in reducing vehicle drag and improving nozzle efficiency. Flight data will be correlated with a concurrent wind tunnel ground test of a similar test apparatus to confirm geometry and component performance scalability predictions and to investigate design parametrics under actual flight conditions. This paper describes the problem of transonic base drag for supersonic and hypersonic aircraft, a planned flight research program to address this problem, the test bed aircraft, and the flight experiment apparatus.

Hicks, John W.↗
NASA NTRS1977

Power converter design optimization

Utilizing the demonstrated capability of nonlinear programming algorithms, a practical design optimization approach for power converters is established to conceive a design to meet all power-circuit performance requirements and concurrently optimize a defined quantity such as weight or losses. In addition, to facilitate a cost-effective design, the computer-aided approach provides a means to readily assess (1) the weight-efficiency tradeoff, (2) impacts of converter requirements and component characteristics on a given design, and (3) optimum power system configurations.

Yu, Y.↗
NASA NTRS1983

The NASA computer science research program plan

A taxonomy of computer science is included, one state of the art of each of the major computer science categories is summarized. A functional breakdown of NASA programs under Aeronautics R and D, space R and T, and institutional support is also included. These areas were assessed against the computer science categories. Concurrent processing, highly reliable computing, and information management are identified.

Source record↗
NASA NTRS2003

Experiments with Test Case Generation and Runtime Analysis

Software testing is typically an ad hoc process where human testers manually write many test inputs and expected test results, perhaps automating their execution in a regression suite. This process is cumbersome and costly. This paper reports preliminary results on an approach to further automate this process. The approach consists of combining automated test case generation based on systematically exploring the program's input domain, with runtime analysis, where execution traces are monitored and verified against temporal logic specifications, or analyzed using advanced algorithms for detecting concurrency errors such as data races and deadlocks. The approach suggests to generate specifications dynamically per input instance rather than statically once-and-for-all. The paper describes experiments with variants of this approach in the context of two examples, a planetary rover controller and a space craft fault protection system.

Artho, Cyrille↗
NASA NTRS2016

COMPASS Final Report: Advanced Long-Life Lander Investigating the Venus Environment (ALIVE)

The COncurrent Multi-disciplinary Preliminary Assessment of Space Systems (COMPASS) Team partnered with the Applied Research Laboratory to perform a NASA Innovative Advanced Concepts (NIAC) Program study to evaluate chemical based power systems for keeping a Venus lander alive(power and cooling) and functional for a period of days. The mission class targeted was either a Discovery ($500M) or New Frontiers ($750M to $780M) class mission. Historic Soviet Venus landers have only lasted on the order of 2 hours in the extreme Venus environment: temperatures of 460 C and pressures of 93 bar. Longer duration missions have been studied using plutonium powered systems to operate and cool landers for up to a year. However, the plutonium load is very large. This NIAC study sought to still provide power and cooling but without the plutonium.

COMPASS↗
NASA NTRS1976

Experimental clean combustor program, phase 2

Combustor pollution reduction technology for commercial CTOL engines was generated and this technology was demonstrated in a full-scale JT9D engine in 1976. Component rig refinement of the two best combustor concepts were tested. These concepts are the vorbix combustor, and a hybrid combustor which combines the pilot zone of the staged premix combustor and the main zone of the swirl-can combustor. Both concepts significantly reduced all pollutant emissions relative to the JT9D-7 engine combustor. However, neither concept met all program goals. The hybrid combustor met pollution goals for unburned hydrocarbons and carbon monoxide but did not achieve the oxides of nitrogen goal. This combustor had significant performance deficiencies. The Vorbix combustor met goals for unburned hydrocarbons and oxides of nitrogen but did not achieve the carbon monoxide goal. Performance of the vorbix combustor approached the engine requirements. On the basis of these results, the vorbix combustor was selected for the engine demonstration program. A control study was conducted to establish fuel control requirements imposed by the low-emission combustor concepts and to identify conceptual control system designs. Concurrent efforts were also completed on two addendums: an alternate fuels addendum and a combustion noise addendum.

Roberts, R.↗
NASA NTRS2017

International Space Station Lithium-Ion Battery Start-Up and Cycling

The International Space Station (ISS) primary Electric Power System (EPS) was originally designed to use Nickel-Hydrogen (Ni-H2) batteries to store electrical energy. The electricity for the ISS is generated by its solar arrays, which charge batteries during insolation for subsequent discharge during eclipse. The Ni-H2 batteries were designed to operate at a 35 depth of discharge (DOD) maximum during normal operation in a Low Earth Orbit. In 2010, the ISS Program began the development of Lithium-Ion (Li-Ion) batteries to replace Ni-H2 batteries approaching the end of their useful life and concurrently funded a Li-Ion ORU (Orbital Replacement Unit) and cell life testing project. The first set of 6 Li-ion battery replacements was launched in December 2016 and deployed in January 2017. This paper will discuss the Li-ion battery on-orbit cycling and the status of the Li-Ion cell and ORU life cycle testing.

International Space Station↗
NASA NTRS1995

Developmental problems and their solution for the Space Shuttle main engine alternate liquid oxygen high-pressure turbopump: Anomaly or failure investigation the key

The Space Shuttle main engine (SSME) alternate high-pressure liquid oxygen pump experienced synchronous vibration and ball bearing life problems that were program threatening. The success of the program hinged on the ability to solve these development problems. The design and solutions to these problems are engirded in the lessons learned and experiences from prior programs, technology programs, and the ability to properly conduct failure or anomaly investigations. The failure investigation determines the problem cause and is the basis for recommending design solutions. For a complex problem, a comprehensive solution requires that formal investigation procedures be used, including fault trees, resolution logic, and action items worked through a concurrent engineering-multidiscipline team. The normal tendency to use an intuitive, cut-and-try approach will usually prove to be costly, both in money and time and will reach a less than optimum, poorly understood answer. The SSME alternate high-pressure oxidizer turbopump development has had two complex problems critical to program success: (1) high synchronous vibrations and (2) excessive ball bearing wear. This paper will use these two problems as examples of this formal failure investigation approach. The results of the team's investigation provides insight into the complexity of the turbomachinery technical discipline interacting/sensitivities and the fine balance of competing investigations required to solve problems and guarantee program success. It is very important to the solution process that maximum use be made of the resources that both the contractor and Government can bring to the problem in a supporting and noncompeting way. There is no place for the not-invented-here attitude. The resources include, but are not limited to: (1) specially skilled professionals; (2) supporting technologies; (3) computational codes and capabilities; and (4) test and manufacturing facilities.

Ryan, R.↗
NASA NTRS1993

Experimental object-level strategic control with cooperating manipulators

This article presents the high-level control module and user interface of the Dynamic and Strategic Control of Cooperating Manipulators (DASCCOM) project at Stanford University's Aerospace Robotics Laboratory. In addition to cooperative dynamic control, DASCCOM incorporates real-time vision-ased feedback, a novel strategic programming technique, and an iconic 'object-only' graphical user interface. By focusing on the vertical integration problem, we are examining not only these subsystems, but also their interfaces and interactions. The control system implements a multilevel hierarchical structure interconnected via a real-time network. At the highest level, a mouse-driven graphical user interface allows an operator to direct the activities of the system conceptually. Strategic command is provided by an event-driven finite state machine. This methodology provides a powerful yet flexible technique for managing concurrent system interactions. The dynamic controller implements object impedance control - an extension of Neville Hogan's impedance control concept to cooperative multiple-arm manipulation of a single object. This article concentrates on user interfacing techniques and strategic programming capabilities. These modules allow the user to directly specify conceptual object relationships. Experimental results are presented, showing the system locating and identifying a moving object, 'catching' it, and performing a simple cooperative assembly. Each of these operations is executed autonomously, with only object-level task-specification direction from a remote operator.

Schneider, Stanley A.↗
NASA NTRS1988

Evolution and use of combined mechanical and thermal codes for cryogenic turbopump bearings

Shaft bearing system analysis codes were developed, improved, and used to investigate Space Shuttle Main Engine (SSME) Liquid Oxygen (LOX) turbopump bearing problems, and to support the Marshall Space Flight Center Bearing and Seal Materials Test (BSMT) program. Thermal network modeling uses the SINDA thermal code, and the modeling of bearing quasi-dynamic characteristics uses the SHABERTH bearing/shaft code. These codes are solved concurrently for a bearing/shaft system using software developed for this purpose. Simulation of the SSME LOX turbopump turbine and pump end bearings and the MSFC BSMT operating in liquid nitrogen (LN sub 2) and LOX was done. The thermal network models include the bearing components, bearing carriers, shaft, housing, frictional heat, and viscous fluid energy. A cage model was included to account for heat generation between the cage and rolling elements. Since most bearing surfaces operate at temperatures well above the coolant saturation temperature, and move at high speed relative to the coolant, forced convection boiling is the dominant mechanism for heat removal. Improved modeling of forced convection film boiling was incorporated to take into account the local vapor generation at the high temperature surfaces. Rearing preloads in the pump and tester are provided by preload springs. As bearing operating clearances and contact angles change due to thermal effects and loading, the bearing preload changes with these varying conditions. These characteristics were modeled and are included in the overall system models. Results from these models indicate an operational limit which, if exceeded, predicts a thermal excursion.

Cody, Joe C.↗
NASA NTRS2010

Integrated Budget Office Toolbox

The Integrated Budget Office Toolbox (IBOT) combines budgeting, resource allocation, organizational funding, and reporting features in an automated, integrated tool that provides data from a single source for Johnson Space Center (JSC) personnel. Using a common interface, concurrent users can utilize the data without compromising its integrity. IBOT tracks planning changes and updates throughout the year using both phasing and POP-related (program-operating-plan-related) budget information for the current year, and up to six years out. Separating lump-sum funds received from HQ (Headquarters) into separate labor, travel, procurement, Center G&A (general & administrative), and servicepool categories, IBOT creates a script that significantly reduces manual input time. IBOT also manages the movement of travel and procurement funds down to the organizational level and, using its integrated funds management feature, helps better track funding at lower levels. Third-party software is used to create integrated reports in IBOT that can be generated for plans, actuals, funds received, and other combinations of data that are currently maintained in the centralized format. Based on Microsoft SQL, IBOT incorporates generic budget processes, is transportable, and is economical to deploy and support.

Rushing, Douglas A.↗
NASA NTRS1996

An Element-Based Concurrent Partitioner for Unstructured Finite Element Meshes

A concurrent partitioner for partitioning unstructured finite element meshes on distributed memory architectures is developed. The partitioner uses an element-based partitioning strategy. Its main advantage over the more conventional node-based partitioning strategy is its modular programming approach to the development of parallel applications. The partitioner first partitions element centroids using a recursive inertial bisection algorithm. Elements and nodes then migrate according to the partitioned centroids, using a data request communication template for unpredictable incoming messages. Our scalable implementation is contrasted to a non-scalable implementation which is a straightforward parallelization of a sequential partitioner.

concurrent partitioner finite element meshes distr↗
NASA NTRS1976

The NASA Space Processing Program

The program is intended to initiate utilization of spaceflight for economically beneficial activities in all branches of materials science and technology. In view of the prospect they offer for reducing the costs of space operations, the Spacelab and Space Shuttle are expected to become widely used for work on materials early in the 1980's. At first they will be employed for space experiments and for services, such as sample preparation, that support research and development activities on the ground. Orbital manufacturing operations are expected to develop as well when research has prepared an adequate basis for them. During the past year, NASA has initiated a series of rocket flights on which prospective participants in the Shuttle/Spacelab program can perform preliminary experiments. Participation in these flights is open to investigators from all countries, and experiments are being solicited from private sponsors also. NASA is performing concurrent definition studies of Shuttle/Spacelab payloads, and design work on equipment for the first two years of operations is planned to begin early in 1977. The Office of Applications currently plans to fly two space processing payloads on Orbital Flight Test missions in 1980 and two on operational Spacelab missions in 1981.

Bredt, J. H.↗