Evolutionary design of smart analog circuits
This paper discusses the use of Evolvable Hardware (EHW) in automatic synthesis of electronic circuits for computational intelligence (CI) hardware.
evolvable hardware fuzzy logic reconfigurable devi↗
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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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Evolutionary mechanisms for smart on-board adaptive sensing applied to the MECA electrometer
In this paper we describe the initial development of efficient mechanisms for smart on-board adaptive sensing, adaptively controlling the reconfigurable pre-processing analog electronics using evolvable hardware, which will lead to higher quality, lean data.
evolvable hardware reconfigurable hardware genetic↗
The Visual Orbit and Evolutionary State of 12 Bootes
Herein we report the determination of the 12 Boo visual orbit from near-infrared, long-baseline interferometric measurements taken with the Palomar Testbed Interferometer (PTI). We further add photometric and spectroscopic measurements in an attempt to understand the fundamental stellar parameters and evolution of the 12 Boo components.
interferometry binary stars stellar astrophysics↗
Evolutionary strategy for the use of nuclear electric propulsion in planetary exploration
This paper focuses on Nuclear Electric Propulsion (NEP) as a means to transport large payloads to targets in the solar system which are energetically difficult to reach.
nuclear electric propulsion mission studies ion pr↗
Evolutionary recovery of electronic circuits from radiation induced faults
Radiation Hard technologies for electronics are the conventional approach for survivability in high radiation environments. This paper presents a novel approach based on Evolvable Hardware.
radiation↗
Evolutionary Technique for Automated Synthesis of Electronic Circuits
An evolvable circuit includes a plurality of reconfigurable switches, a plurality of transistors within a region of the circuit, the plurality of transistors having terminals, the plurality of transistors being coupled between a power source terminal and a power sink terminal so as to be capable of admitting power between the power source terminal and the power sink terminal, the plurality of transistors being coupled so that every transistor to transistor terminal coupling within the region of the circuit comprises a reconfigurable switch.
Stoica, Adrian↗
Microbial Extremophiles in Evolutionary Aspect
The microflora of the cryosphere of planet Earth provides the best analogs for life forms that might be found in the permafrost or polar ice caps of Mars, near the surface of the cometary nuclei, or in the liquid water beneath the ice crusts of icy moons of Jupiter and Saturn. For astrobiology the focus on the study alkaliphilic microorganisms was enhanced by the findings of abundant carbonates and carbonate globules rimmed with possibly biogenic magnetites in association with the putative microfossils in the ALH84001 meteorite. Although the ALH84001 "nanofossils" were to small and simple to be unambiguously recognized as biogenic, they stimulated Astrobiology research and studies of microbial extremophiles and biomarkers in ancient rocks and meteorites. Recent studies of CI and CM carbonaceous meteorites have resulted in the detection of the well-preserved mineralized remains of coccoidal and" filamentous microorganisms in cyanobacterial mats. Energy Dispersive X-ray Analysis has shown anomalous biogenic element ratios clearly indicating they are not recent biological contaminants. This paper reviews microbial extremophiles in context of their significance to Astrobiology and the evolution of life. Extremophilic microorganisms on Earth are models for life that might endure high radiation environments in the ice near the surface of comets or on the icy moons of Jupiter and Saturn and in the seafloor deep beneath the icy crusts of Europa and Enceladus.
Pikuta, Elena V.↗
Evolutionary Technique for Automated Synthesis of Electronic Rircuits
A method of evolving a circuit uses a heterogenous mix of models of both high and low levels of resolution.
Stoica, Adrian↗
Evolutionary Scheduler for the Deep Space Network
A computer program assists human schedulers in satisfying, to the maximum extent possible, competing demands from multiple spacecraft missions for utilization of the transmitting/receiving Earth stations of NASA s Deep Space Network. The program embodies a concept of optimal scheduling to attain multiple objectives in the presence of multiple constraints.
Guillaume, Alexandre↗
NASA's Evolutionary Xenon Thruster (NEXT) Prototype Model 1R (PM1R) Ion Thruster and Propellant Management System Wear Test Results
The results of the NEXT wear test are presented. This test was conducted with a 36-cm ion engine (designated PM1R) and an engineering model propellant management system. The thruster operated with beam extraction for a total of 1680 hr and processed 30.5 kg of xenon during the wear test, which included performance testing and some operation with an engineering model power processing unit. A total of 1312 hr was accumulated at full power, 277 hr at low power, and the remainder was at intermediate throttle levels. Overall ion engine performance, which includes thrust, thruster input power, specific impulse, and thrust efficiency, was steady with no indications of performance degradation. The propellant management system performed without incident during the wear test. The ion engine and propellant management system were also inspected following the test with no indication of anomalous hardware degradation from operation.
VanNoord, Jonathan L.↗
Taking the Evolutionary Road to Developing an In-House Cost Estimate
This slide presentation reviews the process and some of the problems and challenges of developing an In-House Cost Estimate (IHCE). Using as an example the Space Network Ground Segment Sustainment (SGSS) project, the presentation reviews the phases for developing a Cost estimate within the project to estimate government and contractor project costs to support a budget request.
Jacintho, David↗
Supersonics/Airport Noise Plan: An Evolutionary Roadmap
This presentation discusses the Plan for the Airport Noise Tech Challenge Area of the Supersonics Project. It is given in the context of strategic planning exercises being done in other Projects to show the strategic aspects of the Airport Noise plan rather than detailed task lists. The essence of this strategic view is the decomposition of the research plan by Concept and by Tools. Tools (computational, experimental) is the description of the plan that resources (such as researchers) most readily identify with, while Concepts (here noise reduction technologies or aircraft configurations) is the aspects that project management and outside reviewers most appreciate as deliverables and milestones. By carefully cross-linking these so that Concepts are addressed sequentially (roughly one after another) by researchers developing/applying their Tools simultaneously (in parallel with one another), the researchers can deliver milestones at a reasonable pace while doing the longer-term development that most Tools in the aeroacoustics science require. An example of this simultaneous application of tools was given for the Concept of High Aspect Ratio Nozzles. The presentation concluded with a few ideas on how this strategic view could be applied to the Subsonic Fixed Wing Project's Quiet Aircraft Tech Challenge Area as it works through its current roadmapping exercise.
Bridges, James↗
Agriculture for Space Exploration: An Evolutionary Approach for Sustaining Space Agency Investments
No abstract available
Wheeler, Raymond M.↗
Experiments with a Parallel Multi-Objective Evolutionary Algorithm for Scheduling
No abstract available
multi-objective↗
Evolutionary Paths to Internationally-Standardized Space Internetworking
The space community is now poised at the start of an exciting new era of space exploration, where many different organization will be launching spacecraft to investigate nearby bodies, such as the Moon and Mars. International fleets of spacecraft are thus likely to begin to fly and interoperability will often become a mission-enabling technology. These fleets will require a mix of powerful data communications capabilities to be available, ranging from conventional point-to-point architectures to new configurations supporting internetworked operations. This paper reviews the various CCSDS capabilities to support fully-standardized in-space internetworking, and outlines a strategy for smoothly evolving into the new era with minimum impact on the highly successful installed base of CCSDS-compatible systems, which are now widely deployed across the international space community.
Space Internet↗
Rapid Preliminary Design of Interplanetary Trajectories Using the Evolutionary Mission Trajectory Generator
Preliminary design of interplanetary missions is a highly complex process. The mission designer must choose discrete parameters such as the number of flybys, the bodies at which those flybys are performed, and in some cases the final destination. In addition, a time-history of control variables must be chosen that defines the trajectory. There are often many thousands, if not millions, of possible trajectories to be evaluated. This can be a very expensive process in terms of the number of human analyst hours required. An automated approach is therefore very desirable. This work presents such an approach by posing the mission design problem as a hybrid optimal control problem. The method is demonstrated on notional high-thrust chemical and low-thrust electric propulsion missions. In the low-thrust case, the hybrid optimal control problem is augmented to include systems design optimization.
Design↗
Post-Test Inspection of NASA's Evolutionary Xenon Thruster Long-Duration Test Hardware: Discharge and Neutralizer Cathodes
The NEXT Long-Duration Test is part of a comprehensive thruster service life assessment intended to demonstrate overall throughput capability, validate service life models, quantify wear rates as a function of time and operating condition, and identify any unknown life-limiting mechanisms. The test was voluntarily terminated in February 2014 after demonstrating 51,184 hours of high-voltage operation, 918 kg of propellant throughput, and 35.5 MN-s of total impulse. The post-test inspection of the thruster hardware began shortly afterwards with a combination of non-destructive and destructive analysis techniques, and is presently nearing completion. This paper presents relevant results of the post-test inspection for both discharge and neutralizer cathodes. Discharge keeper erosion was found to be significantly reduced from what was observed in the NEXT 2 kh wear test and NSTAR Extended Life Test, providing adequate protection of vital cathode components throughout the test with ample lifetime remaining. The area of the discharge cathode orifice plate that was exposed by the keeper orifice exhibited net erosion, leading to cathode plate material building up in the cathode-keeper gap and causing a thermally-induced electrical short observed during the test. Significant erosion of the neutralizer cathode orifice was also found and is believed to be the root cause of an observed loss in flow margin. Deposition within the neutralizer keeper orifice as well as on the downstream surface was thicker than expected, potentially resulting in a facility-induced impact on the measured flow margin from plume mode. Neutralizer keeper wall erosion on the beam side was found to be significantly lower compared to the NEXT 2 kh wear test, likely due to the reduction in beam extraction diameter of the ion optics that resulted in decreased ion impingement. Results from the post-test inspection have led to some minor thruster design improvements.
Electric Propulsion↗
Post-Test Inspection of NASA's Evolutionary Xenon Thruster Long-Duration Test Hardware: Discharge Chamber
The NEXT Long-Duration Test is part of a comprehensive thruster service life assessment intended to demonstrate overall throughput capability, validate service life models, quantify wear rates as a function of time and operating condition, and identify any unknown life-limiting mechanisms. The test was voluntarily terminated in February 2014 after demonstrating 51,184 hours of high-voltage operation, 918 kg of propellant throughput, and 35.5 MN-s of total impulse. The post-test inspection of the thruster hardware began shortly afterwards with a combination of non-destructive and destructive analysis techniques, and is presently nearing completion. This paper presents relevant results of the post-test inspection for the discharge chamber as well as other miscellaneous components such as the high-voltage propellant isolators and electrical cabling. Comparison of magnetic field measurements taken during pretest and post-test inspections indicate that the field strength did not degrade, consistent with performance data obtained during the test. Inspection of discharge chamber mesh samples show a deposition coating primarily composed of grid material that is approximately 15 micrometers in thickness. This thickness is well within the retention capability of the mesh and is therefore not expected to present any issues. Approximately 3.1 grams of deposition flakes were found at the bottom of the discharge chamber, composed primarily of grid material and carbon. Calculated size histograms of these flakes indicate that 99% have a maximum dimension of 200 micrometers or smaller, which is significantly less than the ion optics grid gap. Larger flakes that are capable of causing a grid-to-grid short will be analyzed to determine if their formation will occur in flight or is a facility effect. The high-voltage propellant isolators as well as numerous other electrical insulators were inspected and no evidence of arcing or any other issues were found.
Electric Propulsion↗