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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 181 records · Page 10
All sourcesNASA NTRSDOE OSTI
NASA NTRS1991

SHARP: Automated monitoring of spacecraft health and status

Briefly discussed here are the spacecraft and ground systems monitoring process at the Jet Propulsion Laboratory (JPL). Some of the difficulties associated with the existing technology used in mission operations are highlighted. A new automated system based on artificial intelligence technology is described which seeks to overcome many of these limitations. The system, called the Spacecraft Health Automated Reasoning Prototype (SHARP), is designed to automate health and status analysis for multi-mission spacecraft and ground data systems operations. The system has proved to be effective for detecting and analyzing potential spacecraft and ground systems problems by performing real-time analysis of spacecraft and ground data systems engineering telemetry. Telecommunications link analysis of the Voyager 2 spacecraft was the initial focus for evaluation of the system in real-time operations during the Voyager spacecraft encounter with Neptune in August 1989.

Atkinson, David J.↗
NASA NTRS1990

SHARP - Automated monitoring of spacecraft health and status

Briefly discussed here are the spacecraft and ground systems monitoring process at the Jet Propulsion Laboratory (JPL). Some of the difficulties associated with the existing technology used in mission operations are highlighted. A new automated system based on artificial intelligence technology is described which seeks to overcome many of these limitations. The system, called the Spacecraft Health Automated Reasoning Prototype (SHARP), is designed to automate health and status analysis for multi-mission spacecraft and ground data systems operations. The system has proved to be effective for detecting and analyzing potential spacecraft and ground systems problems by performing real-time analysis of spacecraft and ground data systems engineering telemetry. Telecommunications link analysis of the Voyager 2 spacecraft was the initial focus for evaluation of the system in real-time operations during the Voyager spacecraft encounter with Neptune in August 1989.

Atkinson, David J.↗
NASA NTRS2005

Robust Load-Sharing Control of Spacecraft Formations

This paper focuses on the design of autonomous and collaborative control strategies to govern the relative distances among multiple spacecraft in formation with no ground intervention. A coordinate load-sharing control structure for formation flying and a methodology to control their dynamic models with slow time-varying and uncertain parameters are the main objectives of this work. The method is applied to a deep space formation example, where the uncertainty in spacecraft fuel masses is also considered.

multi spacecraft↗
NASA NTRS1976

Biomedical Experiments Scientific Satellite /BESS/

The Biomedical Experiments Scientific Satellite (BESS) program is proposed to provide a long-duration, earth-orbiting facility to expose selected specimens in a series of biomedical experiments through the 1980's. Launched and retrieved by the Space Transportation System, the fully reusable, free-flying BESS will contain all systems necessary to conduct a six-month to one-year spaceflight mission. The spacecraft system will consist of a large pressurized experiment module and a standard NASA service module currently conceived as the Goddard Multi-Mission Spacecraft (MMS). The experiment module will contain the life-support systems, waste management system, specimen-holding facilities, and monitoring, evaluating, and data-handling equipment. Although a variety of specimens will be flown in basic biological and medical studies, the primate was taken as the principal design driver since it has a maximal life-support demand.

Berry, W. E.↗
NASA NTRS1984

Instrument pointing technology for spaceborne science missions of the 1990's

The technologies which will permit sub-0.1 arcsec pointing accuracies on spacecraft in the 1990s are examined, along with the accuracies required and the current state of the art. Of particular interest are multi-mission spacecraft. Pointing accuracy can only be obtained by integrating the instrument (telescope) as part of the spacecraft, minimizing disturbances and using reaction wheels for pointing. The pointer could be isolated from complex spacecraft disturbances by soft mechanical mounts, e.g., inflatible tethers, guy-wire suspension and fluidic pointing systems. All design options are being explored for the Space Station, Earth Observing System, Co-orbiting platform and GEO platform spacecraft, and for near-term planetary spacecraft which will employ nuclear electric propulsion.

Laskin, R. A.↗
NASA NTRS1989

In-space technology development: Atomic oxygen and orbital debris effects

Earlier Shuttle flight experiments have shown atomic oxygen within the orbital environment can interact with many materials to produce surface recession and mass loss and combine catalytically with other constituents to generate visible and infrared glows. In addition to these effects, examinations of returned satellite hardware have shown many spacecraft materials are also susceptible to damage from high velocity impacts with orbital space debris. These effects are of particular concern for large, multi-mission spacecraft, such as Space Station and SDI operational satellites, that will operate in low-Earth orbit (LEO) during the late 1990's. Not only must these spacecraft include materials and exterior coatings that are resistant to atomic oxygen surface interactions, but these materials must also provide adequate protection against erosion and pitting that could result from numerous impacts with small particles (less than 100 microns) of orbital space debris. An overview of these concerns is presented, and activities now underway to develop materials and coatings are outlined that will provide adequate atomic protection for future spacecraft. The report also discusses atomic oxygen and orbital debris flight experiments now under development to expand our limited data base, correlate ground-based measurments with flight results, and develop an orbital debris collision warning system for use by future spacecraft.

Visentine, James T.↗
DOE OSTI2025

Simulating many-engine spacecraft: Exceeding 1 quadrillion degrees of freedom via information geometric regularization

We present an optimized implementation of the recently proposed information geometric regularization (IGR) for unprecedented scale simulation of compressible fluid flows applied to multi-engine spacecraft boosters. We improve upon state-of-the-art computational fluid dynamics (CFD) techniques in terms of computational cost, memory footprint, and energy-to-solution metrics. Unified memory on coupled CPU–GPU or APU platforms increases problem size with negligible overhead. Mixed half/single-precision storage and computation are used on well-conditioned numerics. We simulate flow at 200 trillion grid points and 1 quadrillion degrees of freedom, exceeding the current record by a factor of 20. A factor of 4 wall-time speedup is achieved over optimized baselines. Ideal weak scaling is observed on OLCF Frontier, LLNL El Capitan, and CSCS Alps using the full systems. Strong scaling is near ideal at extreme conditions, including 80% efficiency on CSCS Alps with an 8 node baseline and stretching to the full system.

Wilfong, Benjamin [Georgia Institute of Technology↗
NASA NTRS1979

Research study: Space vehicle control systems

From the control point of view, spacecraft are classified into two main groups: those for which the spacecraft is fully defined before the control system is designed; and those for which the control system must be specified before certain interchangeable parts of a multi-purpose spacecraft are selected for future missions. Consideration is given to both classes of problems.

Likins, P. W.↗
NASA NTRS2017

Space Weathering Experiments on Spacecraft Materials

A project to investigate space environment effects on specific materials with interest to remote sensing was initiated in 2016. The goal of the project is to better characterize changes in the optical properties of polymers found in multi-layered spacecraft insulation (MLI) induced by electron bombardment. Previous analysis shows that chemical bonds break and potentially reform when exposed to high energy electrons like those seen in orbit. These chemical changes have been shown to alter a material's optical reflectance, among other material properties. This paper presents the initial experimental results of MLI materials exposed to various fluences of high energy electrons, designed to simulate a portion of the geosynchronous Earth orbit (GEO) space environment. It is shown that the spectral reflectance of some of the tested materials changes as a function of electron dose. These results provide an experimental benchmark for analysis of aging effects on satellite systems which can be used to improve remote sensing and space situational awareness. They also provide preliminary analysis on those materials that are most likely to comprise the high area-to-mass ratio (HAMR) population of space debris in the geosynchronous orbit environment. Finally, the results presented in this paper serve as a proof of concept for simulated environmental aging of spacecraft polymers that should lead to more experiments using a larger subset of spacecraft materials.

Engelhart, D. P.↗
NASA NTRS2017

Space Weathering Experiments on Spacecraft Materials

A project to investigate space environment effects on specific materials with interest to remote sensing was initiated in 2016. The goal of the project is to better characterize changes in the optical properties of polymers and Mylar, specifically those found in multi-layered spacecraft insulation, due to electron bombardment. Previous analysis shows that chemical bonds break and potentially reform when exposed to high energy electrons. Among other properties these chemical changes altered the optical reflectance as documented in laboratory analysis. This paper presents results of the initial experiment results focused on the exposure of materials to various fluences of high energy electrons, used to simulate a portion of the geosynchronous space environment. The paper illustrates how the spectral reflectance changes as a function of time on orbit with respect to GEO environmental factors and investigates the survivability of the material after multiple electron doses. These results provide a baseline for analysis of aging effects on satellite systems used for remote sensing. They also provide preliminary analysis on what materials are most likely to encompass the high area-to-mass population of space debris in the geosynchronous environment. Lastly, the paper provides the results of the initial experimentation as a proof of concept for space aging on polymers and Mylar for conducting more experiments with a larger subset of spacecraft materials.

Cooper, R.↗
NASA NTRS2002

System engineering challenges of real-time simulation for Mars SmartLander entry, descent, and landing

The Jet Propulsion Laboratory (JPL) is developing a high-fidelity, real-time spacecraft simulator for Entry, Descent and Landing (EDL) on planetary and small bodies. This simulator, DSENDS (Dynamics Simulator for Entry, Descent and Surface landing), is an EDL-specific extension of the JPL Darts/Dshell multi-mission spacecraft dynamics and devices simulation toolkit which is in use by missions such as Cassini, Galileo, SIM, and Starlight.

Dshell EDL simulator↗
NASA NTRS2007

Multi-Functional Sandwich Composites for Spacecraft Applications: An Initial Assessment

Current spacecraft implement relatively uncoupled material and structural systems to address a variety of design requirements, including structural integrity, damage tolerance, radiation protection, debris shielding and thermal insulation. This investigation provided an initial assessment of multi-functional sandwich composites to integrate these diverse requirements. The need for radiation shielding was addressed through the selection of polymeric constituents with high hydrogen content. To provide increased damage tolerance and debris shielding, manufacturing techniques were developed to incorporate transverse stitching reinforcement, internal layers, and a self-healing ionomer membrane. To assess the effects of a space environment, thermal expansion behavior of the candidate foam materials was investigated under a vacuum and increasing temperature. Finally, a thermal expansion model was developed for foam under vacuum conditions and its predictive capability assessed.

Adams, Daniel O.↗
NASA NTRS2004

Space mission scenario development and performance analysis tool

This paper discusses a new and innovative approach for a rapid spacecraft multi-disciplinary performance analysis using a tool called the Mission Scenario Development Workbench (MSDW). To meet the needs of new classes of space missions, analysis tools with proven models were developed and integrated into a framework to enable rapid trades and analyses between spacecraft designs and operational scenarios during the formulation phase of a mission. Generally speaking, spacecraft resources are highly constrained on deep space missions and this approach makes it possible to maximize the use of existing resources to attain the best possible science return. This approach also has the potential benefit of reducing the risk of costly design changes made later in the design cycle necessary to meet the mission requirements by understanding system design sensitivities early and adding appropriate margins. This paper will describe the approach used by the Mars Science Laboratory Project to accomplish this result.

performance analysis↗
NASA NTRS1975

Tape tracking and handling for magnetic tape recorders

One of the critical performance and life limiting elements of a spacecraft tape recorder instrumentation system which has received little attention in technical literature is magnetic tape tracking and handling technology. This technology is required to understand how to gently transfer tape from one reel to another with proper alignment and a desirable uniform velocity at the read and write transducer heads. The increased demand for high data rate (i.e., multi-track spacecraft recording instrumentation systems), coupled with performance under extreme environmental conditions, requires a thorough knowledge of the various parameters which establish an optimum designed tape tracking and handling system. Stress analysis techniques are required to evaluate these parameters substantiated with test tape tracking data, to show the effect of each parameter on a tape recorder instrumentation tracking system. The technology is applicable to ground type tape recorders where the detrimental effects of edge guidance can be eliminated.

Paroby, W.↗
NASA NTRS2006

Adjustably Autonomous Multi-agent Plan Execution with an Internal Spacecraft Free-Flying Robot Prototype

We present an multi-agent model-based autonomy architecture with monitoring, planning, diagnosis, and execution elements. We discuss an internal spacecraft free-flying robot prototype controlled by an implementation of this architecture and a ground test facility used for development. In addition, we discuss a simplified environment control life support system for the spacecraft domain also controlled by an implementation of this architecture. We discuss adjustable autonomy and how it applies to this architecture. We describe an interface that provides the user situation awareness of both autonomous systems and enables the user to dynamically edit the plans prior to and during execution as well as control these agents at various levels of autonomy. This interface also permits the agents to query the user or request the user to perform tasks to help achieve the commanded goals. We conclude by describing a scenario where these two agents and a human interact to cooperatively detect, diagnose and recover from a simulated spacecraft fault.

Dorais, Gregory A.↗
NASA NTRS2012

The Height of a White-Light Flare and its Hard X-Ray Sources

We describe observations of a white-light (WL) flare (SOL2011-02-24T07:35:00, M3.5) close to the limb of the Sun, from which we obtain estimates of the heights of the optical continuum sources and those of the associated hard X-ray (HXR) sources. For this purpose, we use HXR images from the Reuven Ramaty High Energy Spectroscopic Imager and optical images at 6173 Ang. from the Solar Dynamics Observatory.We find that the centroids of the impulsive-phase emissions in WL and HXRs (30 -80 keV) match closely in central distance (angular displacement from Sun center), within uncertainties of order 0".2. This directly implies a common source height for these radiations, strengthening the connection between visible flare continuum formation and the accelerated electrons. We also estimate the absolute heights of these emissions as vertical distances from Sun center. Such a direct estimation has not been done previously, to our knowledge. Using a simultaneous 195 Ang. image from the Solar-Terrestrial RElations Observatory spacecraft to identify the heliographic coordinates of the flare footpoints, we determine mean heights above the photosphere (as normally defined; tau = 1 at 5000 Ang.) of 305 +/- 170 km and 195 +/- 70 km, respectively, for the centroids of the HXR and WL footpoint sources of the flare. These heights are unexpectedly low in the atmosphere, and are consistent with the expected locations of tau = 1 for the 6173 Ang and the approx 40 keV photons observed, respectively.

Sun: photosphere↗
NASA NTRSDate not supplied

HelioSwarm: The Swarm is the Observatory

The HelioSwarm Mission will transform our understanding of space plasma turbulence by being the first-of-its-kind simultaneous, multiscale observatory comprising multiple spacecraft. HelioSwarm was competitively selected under the Heliophysics Explorers Program 2019 Medium-Class Explorer (MIDEX) Announcement of Opportunity. The central powered-ESPA Hub spacecraft is co-orbited by eight SmallSat Node spacecraft, together moving through a High Earth Orbit to obtain data in various solar wind regimes. The mission architecture is that of hub-and-spoke, with the larger hub serving as a communications relay between the Nodes and DSN. Mission operations, management, and technical oversight are provided by NASA Ames Research Center; the spacecraft are provided by Northrop Grumman and BCT. The instrument suite includes foreign-contributed instruments and U.S. ones, all under the oversight of University of New Hampshire (which is also the Principal Investigator’s home institution and Science Operations Center). The mission timeline from launch through conclusion of the one-year science mission is provided along with a summarized concept of operations, with particular emphasis on placing the Nodes in their proper relative orbit loops to form the geometry needed for science collection at apogee. A brief discussion of how a combination of legacy tools and custom-created swarm analysis tools are used to design the swarm and sort and visualize the collected science data and telemetry in context is provided. Finally, an exploration of the pathfinding nature of HelioSwarm and some implications for future large scientific swarms is offered.

Heliophysics↗