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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 775 records · Page 43
All sourcesNASA NTRSDOE OSTI
NASA NTRS2006

Practical Application of Model-based Programming and State-based Architecture to Space Missions

A viewgraph presentation to develop models from systems engineers that accomplish mission objectives and manage the health of the system is shown. The topics include: 1) Overview; 2) Motivation; 3) Objective/Vision; 4) Approach; 5) Background: The Mission Data System; 6) Background: State-based Control Architecture System; 7) Background: State Analysis; 8) Overview of State Analysis; 9) Background: MDS Software Frameworks; 10) Background: Model-based Programming; 10) Background: Titan Model-based Executive; 11) Model-based Execution Architecture; 12) Compatibility Analysis of MDS and Titan Architectures; 13) Integrating Model-based Programming and Execution into the Architecture; 14) State Analysis and Modeling; 15) IMU Subsystem State Effects Diagram; 16) Titan Subsystem Model: IMU Health; 17) Integrating Model-based Programming and Execution into the Software IMU; 18) Testing Program; 19) Computationally Tractable State Estimation & Fault Diagnosis; 20) Diagnostic Algorithm Performance; 21) Integration and Test Issues; 22) Demonstrated Benefits; and 23) Next Steps

Mission Data System (MDS)↗
NASA NTRS2006

Transforming Space Missions into Service Oriented Architectures

This viewgraph presentation reviews the vision of the sensor web enablement via a Service Oriented Architecture (SOA). An generic example is given of a user finding a service through the Web, and initiating a request for the desired observation. The parts that comprise this system and how they interact are reviewed. The advantages of the use of SOA are reviewed.

Mandl, Dan↗
NASA NTRS2005

Probabilistic Risk Assessment for Concurrent, Conceptual Design of Space Missions

NASA is expanding its capability to perform PRA. This capability gives insight into the links of a suggested design and drives the refinement of the design by identifying optimal areas for investments. Clearly, it is more viable and less expensive to refine a design at the time that it is being conceived. Hence the utility of conducting PRA at the conceptual design phase. Concurrent engineering teams greatly reduce the design time and costs. However, there is currently no standardized means for building probabilistic risk models to assess risks associated with a design produced by such teams. The capability to produce a consistent and valid risk metric associated with such designs would greatly enhance the value of such design teams. This paper explains the experimental results obtained to date from building probabilistic risk models for sample studies conducted at the concurrent engineering design team at the Jet Propulsion Laboratory (TeamX).

conceptual designs↗
NASA NTRS2005

A Rapid, Flexible Approach to Conceptual Space Mission Tradespace Definition and Exploration

This paper provides an overview of the Mission Tradespace Tool (MTT), a methodology and software framework developed to improve JPL's early design process by offering a rapid, structured, and inexpensive way to identify feasible design architectures from a wide array of candidate architectures. There has been a growing consensus at JPL that to improve the quality of service offered to design customers it is desirable to explore a wide tradespace of candidate architectures prior to forming a conceptual design baseline. This paper describes the rationale behind the MTT's approach to meet this need. Notable features of the framework are introduced and explained.

early designs↗
NASA NTRS2006

The Fourier-Kelvin Stellar Interferometer a Low Complexity, Low Cost Space Mission for High-Resolution Astronomy and Direct Exoplanet Detection

The Fourier-Kelvin Stellar Interferometer (FKSI) is a mission concept for a spacecraft-borne nulling interferometer for high-resolution astronomy and the direct detection of exoplanets and assay of their environments and atmospheres. FKSI is a high angular resolution system operating in the near to midinfrared spectral region and is a scientific and technological pathfinder to the Darwin and Terrestrial Planet Finder (TPF) missions. The instrument is configured with an optical system consisting, depending on configuration, of two 0.5 - 1.0 m telescopes on a 12.5 - 20 m boom feeding a symmetric, dual Mach- Zehnder beam combiner. We report on progress on our nulling testbed including the design of an optical pathlength null-tracking control system and development of a testing regime for hollow-core fiber waveguides proposed for use in wavefront cleanup. We also report results of integrated simulation studies of the planet detection performance of FKSI and results from an in-depth control system and residual optical pathlength jitter analysis.

Barry, R. K.↗
NASA NTRS2005

Automated Planning and Scheduling for Space Mission Operations

Research Trends: a) Finite-capacity scheduling under more complex constraints and increased problem dimensionality (subcontracting, overtime, lot splitting, inventory, etc.) b) Integrated planning and scheduling. c) Mixed-initiative frameworks. d) Management of uncertainty (proactive and reactive). e) Autonomous agent architectures and distributed production management. e) Integration of machine learning capabilities. f) Wider scope of applications: 1) analysis of supplier/buyer protocols & tradeoffs; 2) integration of strategic & tactical decision-making; and 3) enterprise integration.

scheduling↗
NASA NTRS2003

Use of Earth-Based Analogs for Long-Duration Space Missions

The presentation reviews the Integrated Human Exploration Mission Simulation Facility (INTEGRITY). Topics include capability development; general attributes of human exploration missions beyond low Earth orbit; objectives of INTEGRITY; and other aspects such as education and outreach; public affairs; and international, commercial, and academic partnering.

Henninger, Donald L.↗
NASA NTRS2010

Heritage and Advanced Technology Systems Engineering Lessons Learned from NASA Space Missions

Use of heritage and new technology is necessary/enabling to implementing small, low cost missions, yet overruns decrease the ability to sustain future mission flight rates The majority of the cost growth drivers seen in the D&NF study were embedded early during formulation phase and later realized during the development and I&T phases Cost drivers can be avoided or significantly decreased by project management and SE emphasis on early identification of risks and realistic analyses SE processes that emphasize an assessment of technology within the mission system to identify technical issues in the design or operational use of the technology. Realistic assessment of new and heritage spacecraft technology assumptions , identification of risks and mitigation strategies. Realistic estimates of effort required to inherit existing or qualify new technology, identification of risks to estimates and develop mitigation strategies. Allocation of project reserves for risk-based mitigation strategies of each individual area of heritage or new technology. Careful tailoring of inheritance processes to ensure due diligence.

Barley, Bryan↗
NASA NTRS2011

Identification of Cardiometabolic Vulnerabilities Caused by Effects of Synergistic Stressors that are Commonly Encountered During Space Missions

Microgravity is a physiologically challenging state even when at rest. Astronauts experience additional physical and mental stresses, such as prolonged exertion, sleep loss and circadian misalignment, that could impact cardiovascular function. The main goals of this four year NASA project are to characterize the independent and synergistic effects on cardiovascular and immune function of: (1) circadian misalignment; (2) sleep loss; and (3) varied physical and mental stressors, mimicking some of the synergistic stressors experienced by astronauts. Sixteen healthy volunteers, aged 35-55 years, will be studied with standardized behavioral stressors occurring across all circadian phases, both with and without accruing sleep loss, achieved via two 11-day "forced desynchrony" protocols performed in each subject (randomized, within-subject design), where wake periods are advanced 4-h each "day" (i.e. recurring 20-h "days"). One protocol permits 8.33 h sleep opportunity per 20-h "day" (=10 h sleep per 24-h), and the other permits 5 h sleep per 20-h "day" (=6 h sleep per 24-h; matching the reported sleep duration of astronauts). In both protocols, subjects will perform a standardized stress battery including a cognitively challenging task; bicycle exercise, and passive 60deg head up tilt. Outcome variables include blood pressure, heart rate, arrhythmia frequency, cardiac vagal tone (from heart rate variability), sympathetic activity (catecholamines), and endothelial function. Additional measures of cardiac function (echocardiography), responses to a passive 80deg head up tilt, maximal oxygen uptake, and immune function will be assessed at the beginning and at the end of each protocol (i.e., without and with sleep loss, and before and after circadian misalignment). We hope to identify the relative impact on cardiovascular risk markers of varied behavioural stressors while subjects experience circadian misalignment and sleep loss, mimicking some of the synergistic stressors experienced by astronauts. Supported by NASANNX1 OAR 1 OG.

Ruger, M.↗
NASA NTRS2011

Systems Engineering Using Heritage Spacecraft Technology: Lessons Learned from Discovery and New Frontiers Deep Space Missions

In the design and development of complex spacecraft missions, project teams frequently assume the use of advanced technology or heritage systems to enable a mission or reduce the overall mission risk and cost. As projects proceed through the development life cycle, increasingly detailed knowledge of the advanced or heritage systems and the system environment identifies unanticipated issues that result in cost overruns or schedule impacts. The Discovery & New Frontiers (D&NF) Program Office recently studied cost overruns and schedule delays resulting from advanced technology or heritage assumptions for 6 D&NF missions. The goal was to identify the underlying causes for the overruns and delays, and to develop practical mitigations to assist the D&NF projects in identifying potential risks and controlling the associated impacts to proposed mission costs and schedules. The study found that the cost and schedule growth did not result from technical hurdles requiring significant technology development. Instead, systems engineering processes did not identify critical issues early enough in the design cycle to ensure project schedules and estimated costs address the inherent risks. In general, the overruns were traceable to: inadequate understanding of the heritage system s behavior within the proposed spacecraft design and mission environment; an insufficient level of experience with the heritage system; or an inadequate scoping of the system-wide impacts necessary to implement the heritage or advanced technology. This presentation summarizes the study s findings and offers suggestions for improving the project s ability to identify and manage the risks inherent in the technology and heritage design solution.

Barley, Bryan↗
NASA NTRS2011

High Power Electric Propulsion for Deep Space Missions

Slide presentation reviews: (1) An Electric Propulsion Primer (2) The Flexible Path and the Electric Path (2a) A New Plan for Human Exploration (2b)The Role of Electric Propulsion (3) High Power Electric Thrusters (3a)Hall Thrusters (3b) Magnetoplasmadynamic Thrusters (4)Challenges for the Next Generation of Advanced Propulsion Technologist

human exploration↗
NASA NTRS2010

Interpreting Space-Mission LET Requirements for SEGR in Power MOSFETs

A Technology Computer Aided Design (TCAD) simulation-based method is developed to evaluate whether derating of high-energy heavy-ion accelerator test data bounds the risk for single-event gate rupture (SEGR) from much higher energy on-orbit ions for a mission linear energy transfer (LET) requirement. It is shown that a typical derating factor of 0.75 applied to a single-event effect (SEE) response curve defined by high-energy accelerator SEGR test data provides reasonable on-orbit hardness assurance, although in a high-voltage power MOSFET, it did not bound the risk of failure.

Lauenstein, J. M.↗
NASA NTRS2011

TAMU: A New Space Mission Operations Paradigm

The Transferable, Adaptable, Modular and Upgradeable (TAMU) Flight Production Process (FPP) is a model-centric System of System (SoS) framework which cuts across multiple organizations and their associated facilities, that are, in the most general case, in geographically diverse locations, to develop the architecture and associated workflow processes for a broad range of mission operations. Further, TAMU FPP envisions the simulation, automatic execution and re-planning of orchestrated workflow processes as they become operational. This paper provides the vision for the TAMU FPP paradigm. This includes a complete, coherent technique, process and tool set that result in an infrastructure that can be used for full lifecycle design and decision making during any flight production process. A flight production process is the process of developing all products that are necessary for flight.

Meshkat, Leila↗
NASA NTRS2011

NEXUS Scalable and Distributed Next-Generation Avionics Bus for Space Missions

A paper discusses NEXUS, a common, next-generation avionics interconnect that is transparently compatible with wired, fiber-optic, and RF physical layers; provides a flexible, scalable, packet switched topology; is fault-tolerant with sub-microsecond detection/recovery latency; has scalable bandwidth from 1 Kbps to 10 Gbps; has guaranteed real-time determinism with sub-microsecond latency/jitter; has built-in testability; features low power consumption (< 100 mW per Gbps); is lightweight with about a 5,000-logic-gate footprint; and is implemented in a small Bus Interface Unit (BIU) with reconfigurable back-end providing interface to legacy subsystems. NEXUS enhances a commercial interconnect standard, Serial RapidIO, to meet avionics interconnect requirements without breaking the standard. This unified interconnect technology can be used to meet performance, power, size, and reliability requirements of all ranges of equipment, sensors, and actuators at chip-to-chip, board-to-board, or box-to-box boundary. Early results from in-house modeling activity of Serial RapidIO using VisualSim indicate that the use of a switched, high-performance avionics network will provide a quantum leap in spacecraft onboard science and autonomy capability for science and exploration missions.

He, Yutao↗
NASA NTRS2012

Validation of Battery Safety for Space Missions

Presentation covers: (1) Safety Certification Process at NASA (2) Safety Testing for Lithium-ion Batteries (3) Limitations Observed with Li-ion Batteries in High Voltage and High Capacity Configurations.

Jeevarajan, Judith↗