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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 55 records · Page 3
All sourcesNASA NTRSDOE OSTI
NASA NTRS2009

Simulation Evaluation of Equivalent Vision Technologies for Aerospace Operations

A fixed-based simulation experiment was conducted in NASA Langley Research Center s Integration Flight Deck simulator to investigate enabling technologies for equivalent visual operations (EVO) in the emerging Next Generation Air Transportation System operating environment. EVO implies the capability to achieve or even improve on the safety of current-day Visual Flight Rules (VFR) operations, maintain the operational tempos of VFR, and perhaps even retain VFR procedures - all independent of the actual weather and visibility conditions. Twenty-four air transport-rated pilots evaluated the use of Synthetic/Enhanced Vision Systems (S/EVS) and eXternal Vision Systems (XVS) technologies as enabling technologies for future all-weather operations. The experimental objectives were to determine the feasibility of XVS/SVS/EVS to provide for all weather (visibility) landing capability without the need (or ability) for a visual approach segment and to determine the interaction of XVS/EVS and peripheral vision cues for terminal area and surface operations. Another key element of the testing investigated the pilot's awareness and reaction to non-normal events (i.e., failure conditions) that were unexpectedly introduced into the experiment. These non-normal runs served as critical determinants in the underlying safety of all-weather operations. Experimental data from this test are cast into performance-based approach and landing standards which might establish a basis for future all-weather landing operations. Glideslope tracking performance appears to have improved with the elimination of the approach visual segment. This improvement can most likely be attributed to the fact that the pilots didn't have to simultaneously perform glideslope corrections and find required visual landing references in order to continue a landing. Lateral tracking performance was excellent regardless of the display concept being evaluated or whether or not there were peripheral cues in the side window. Although workload ratings were significantly less when peripheral cues were present compared to when there were none, these differences appear to be operationally inconsequential. Larger display concepts tested in this experiment showed significant situation awareness (SA) improvements and workload reductions compared to smaller display concepts. With a fixed display size, a color display was more influential in SA and workload ratings than a collimated display.

Kramer, Lynda J.↗
DOE OSTI2022

Quantitative Morphological Characterization of Carbide Inclusions in Uranium Metal

Uranium carbides (UCs) are prevalent inclusions in U metal that form during melting operations from interactions with crucible walls and the casting chamber atmosphere. Although UCs have been studied extensively since the beginning of U metal foundry operations, there are still unknowns regarding the effects of thermomechanical processing on their sizes and morphology. Here, we present the results of a series of controlled cooling experiments with molten uranium to elucidate the effect of cooling rate on inclusion morphology in a-U. Samples were melted using a vacuum induction melter and manually cooled at rates of 2.5, 1.7, 1.1, 0.8, 0.3 (± 1%) K/s from ~1600 K to <700 K in under 1 hour. Subsequent scanning electron microscopy (SEM) was performed on cross-sections of the samples, revealing a complex mixture of UC morphologies that are indicative of diffusion and growth influenced by the thermal processing of the U matrix. Image analysis using the Morphological Analysis of Materials (MAMA) software showed that UC sizes generally grew larger with slower cooling rates, and the two slowest cooling rates noticeably impacted the inclusion circularity and ellipse aspect ratio. These results indicate that UC morphology is sensitive to short cooling rates (<1 hour) and could therefore be controlled in the production of metallic nuclear fuels. Additionally, inclusion speciation and morphologies could potentially provide forensic clues about processing history of unknown metal samples. Understanding the driving forces involved in UC morphology evolution is beneficial for evaluating metal fuels for next generation nuclear reactors and for identifying signatures for nuclear forensics.

Athon, Matthew T.↗
DOE OSTI2025

Center for Alternate Synchronization and Timing (CAST) PTP Network Monitoring Report

The Oak Ridge National Laboratory Center for Alternative Synchronization and Timing (CAST) performs research, development, testing, and evaluation of alternative terrestrial-based timing and synchronization infrastructure for the US power grid and other critical infrastructures. Alternative timing options reduce reliance on GPS and enhance the overall resilience of critical infrastructures. CAST infrastructure uses Precision Time Protocol (PTP) as the primary conduit for delivery of synchronization packets. CAST deploys PTP over long terrestrial links to synchronize a multitude of remote boundary clocks and downstream power grid components with the authoritative grand master clocks. Network traffic issues can severely degrade PTP accuracy. This report focuses on examining network traffic anomalies and their effects on PTP operation as well as the potential implications to CAST’s high-precision remote synchronization operations.

24 POWER TRANSMISSION AND DISTRIBUTION↗
NASA NTRS1986

Pressure Rig for Repetitive Casting

Equipment life increased by improved insulation. New design cuts time of preparation for casting from several days to about 1 hour. Savings due to elimination of lengthy heating and drying operations associated with preparation of ceramic mold. Quality of casting improved because moisture in cavity eliminated by use of insulating material, and more uniform pressure applied to process. Commercial blanket insulator protects components from heat, increasing life of pressure rig and enabling repeated use. Improved heat protection allows casting of brass and other alloys with higher melting temperatures in pressure rig.

Vasquez, P.↗
NASA NTRS1983

Properties of Nickel-Based Hydrogen-Turbine Blades

120 page report presents data on mechanical properties of cast nickelbased alloys for turbine blades operating in hydrogen and steam at high temperatures. Tests on alloys for hydrogen-burning engines of future are described.

Deluca, D. P.↗
NASA NTRS1982

Honeycomb mirrors of borosilicate glass

The fabrication of different types of honeycomb mirrors with various kinds of borosilicate glass is discussed. Borosilicate glass is much less expensive to make than zero expansion glass, and can be used for ground-based applications. A mirror 60 cm in diameter made with a slotted strut or egg-crate honeycomb of 6 mm polished Pyrex plate is shown. The faceplates are 12 mm thick, laminated from the same 6 mm sheet. The result of an interferometric test is shown, with residual errors of about wavelength/8 RMS. An alternative fabrication technique for very large mirrors which require high quality bonds between separate sheets of thick Pyrex is described. The result of a recent test casting of a 60 cm honeycomb structure made in a mold with towers 14 cm square and 6 mm gaps between is shown, and methods to cast an entire mirror in one operation are discussed.

Angel, J. R. P.↗
NASA NTRS1992

Space Transportation Main Engine

The topics are presented in viewgraph form and include the following: Space Transportation Main Engine (STME) definition, design philosophy, robust design, maximum design condition, casting vs. machined and welded forgings, operability considerations, high reliability design philosophy, engine reliability enhancement, low cost design philosophy, engine systems requirements, STME schematic, fuel turbopump, liquid oxygen turbopump, main injector, and gas generator. The major engine components of the STME and the Space Shuttle Main Engine are compared.

Jan C. Monk↗
NASA NTRS1991

Study of mass and heat transport of the tropical Atlantic Ocean using models and altimeter data

The specific objectives of this proposal are: (1) to assess the quality of the TOPEX/POSEIDON surface altimeter data in regard to its use for a large, low-frequency monitoring of the surface topography of the tropical Atlantic Ocean; (2) to develop a method, on a demonstration basis, to derive from the tropical Atlantic the depth of the thermocline and the heat content changes from the surface altimeter data field; (3) to develop a method of assimilation of altimeter data into Oceanic General Circulation Models (OGCM's) for the purpose of preparing an operational, permanent, three-dimensional now casting of the tropical Atlantic Ocean (a TOGA objective); and (4) to derive from these models global circulation fields and a time series of mass and meridional heat transports across the tropical Atlantic region (a WOCE objective).

Merle, Jacques↗
NASA NTRS2020

Identification of Scenarios for System Interface Design Evaluation: CAST SE-210 Output 2 Report 5 of 6

This report is one in a series of reports describing research to develop enhanced approaches to design and evaluation of flight deck interaction. The research was conducted to support the Commercial Aviation Safety Team (CAST) response to incidents and accidents caused by failure of the flight crew to maintain aircraft attitude or energy state awareness. This report partially responds to Safety Enhancement (SE) 210.2 (CAST, 2014) by describing development of operational scenarios for evaluation of flight crew interaction. Evaluations of human performance with an interface rely on asking humans to perform operational tasks in an appropriate operational context. The report includes the major sources of material for developing operational scenarios—which include system state, operational tasks, operational context, and safety events—and a method for developing an appropriate set of operational scenarios for interface evaluation.

commercial aviation↗
NASA NTRS2017

Progress of Crew Autonomous Scheduling Test (CAST) On the ISS

The United States space policy is evolving toward missions beyond low Earth orbit. In an effort to meet that policy, NASA has recognized Autonomous Mission Operations (AMO) as a valuable capability. Identified within AMO capabilities is the potential for autonomous planning and replanning during human spaceflight operations. That is allowing crew members to collectively or individually participate in the development of their own schedules. Currently, dedicated mission operations planners collaborate with international partners to create daily plans for astronauts aboard the International Space Station (ISS), taking into account mission requirements, ground rules, and various vehicle and payload constraints. In future deep space operations the crew will require more independence from ground support due to communication transmission delays. Furthermore, crew members who are provided with the capability to schedule their own activities are able to leverage direct experience operating in the space environment, and possibly maximize their efficiency. CAST (Crew Autonomous Scheduling Test) is an ISS investigation designed to analyze three important hypotheses about crew autonomous scheduling. First, given appropriate inputs, the crew is able to create and execute a plan in a reasonable period of time without impacts to mission success. Second, the proximity of the planner, in this case the crew, to the planned operations increases their operational efficiency. Third, crew members are more satisfied when given a role in plan development. This presentation shows the progress done in this study with a single astronaut test subject participating in five CAST sessions. CAST is a technology demonstration payload sponsored by the ISS Research Science and Technology Office, and performed by experts in Mission Operations Planning from the Flight Operations Directorate at NASA Johnson Space Center, and researchers across multiple NASA centers.

Healy, Matthew↗
NASA NTRS2019

Lessons Learned from International Space Station Crew Autonomous Scheduling Test

In 2017, our team investigated and evaluated the novel concept of operations of astronaut self-scheduling (rescheduling their own timeline without creating violations) onboard International Space Station (ISS). Five test sessions were completed for this technology demonstration called Crew Autonomous Scheduling Test (CAST). For the first time in a spaceflight operational environment, an ISS crewmember planned, rescheduled, and executed their activities in real-time on a mobile device while abiding by flight and scheduling constraints. This paper discusses the lessons learned from deployment to execution.

planning and scheduling↗
NASA NTRS1959

Performance of Two Boron-Modified S-816 Alloys in a Turbojet Engine Operated at 1650 F

S-816+B and modified S-816+B cast cobalt-base alloys were evaluated as turbine-bucket materials at 16500 F. Stress-rupture and tensile data obtained from these alloys had indicated satisfactory strength for engine operation at 1650 F. Although both alloys exhibited a limited ductility in room-temperature laboratory impact tests, there was a significant increase in impact resistance in the 1650 F tests. Bucket failures began after 10 hours of engine testing and continued at various intervals during the 107.5-hour test. Bucket lives were short relative to the predicted lives based on stress-rupture considerations (280 hr for S-816+B and 1750 hr for modified S-816+B). No significant difference was apparent in the performance of the two alloy groups. The primary cause of bucket failures in both alloys was mechanical fatigue. Impact damage occurred as a direct result of bucket tip fatigue failures and was a secondary cause of bucket failures. The impact of small pieces of fractured bucket tips on surrounding buckets caused a relatively large amount of impact damage to buckets of both alloys. The amount of impact damage from induced fractures at the bucket midspan, which provided relatively large failed fragments, was no greater than that which occurred as a result of tip failures.

Waters, William J.↗
NASA NTRS1992

Coating Of Molded Battery Substrates

Materials applied to molds as powders, dispersions, or solutions not only enable release of molded parts from molds, but also enhance properties of surfaces of parts. Applied to casting of lead grids or other molding operations in which powdered materials adhering to molded parts improve properties of surfaces.

Larkin, Terrance M.↗
NASA NTRS2007

Digital Learning Network Education Events of NASA's Extreme Environments Mission Operations

NASA's Digital Learning Network (DLN) reaches out to thousands of students each year through video conferencing and web casting. The DLN has created a series of live education videoconferences connecting NASA s Extreme Environment Missions Operations (NEEMO) team to students across the United States. The programs are also extended to students around the world live web casting. The primary focus of the events is the vision for space exploration. During the programs, NEEMO Crewmembers including NASA astronauts, engineers and scientists inform and inspire students about the importance of exploration and share the impact of the project as it correlates with plans to return to the moon and explore the planet Mars. These events highlight interactivity. Students talk live with the aquanauts in Aquarius, the National Oceanic and Atmospheric Administration s underwater laboratory. With this program, NASA continues the Agency s tradition of investing in the nation's education programs. It is directly tied to the Agency's major education goal of attracting and retaining students in science, technology, and engineering disciplines. Before connecting with the aquanauts, the students conduct experiments of their own designed to coincide with mission objectives. This paper describes the events that took place in September 2006.

Paul, Heather↗
NASA NTRS2016

Resource Prospector Landing Site and Traverse Plan Development

Resource Prospector (RP) will be the first lunar surface robotic expedition to explore the character and feasibility of in situ resource utilization at the lunar poles. It is aimed at determining where, and how much, hydrogen-bearing and other volatiles are sequestered in polar cold traps. To meet its goals, the mission should land where the likelihood of finding polar volatiles is high. The operational environment is challenging: very low sun elevations, long shadows cast by even moderate relief, cryogenic subsurface temperatures, unknown regolith properties, and very dynamic sun and Earth communications geometries force a unique approach to landing, traverse design and mission operations.

lunar poles↗
NASA NTRS2017

Landing Site and Traverse Plan Development for Resource Prospector

Resource Prospector (RP) will be the first lunar surface robotic expedition to explore the character and feasibility of in situ resource utilization at the lunar poles. It is aimed at determining where, and how much, hydrogen-bearing and other volatiles are sequestered in polar cold traps. To meet its goals, the mission should land where the likelihood of finding polar volatiles is high [1,2,3]. The operational environment is challenging: very low sun elevations, long shadows cast by even moderate relief, cryogenic subsurface temperatures, unknown regolith properties, and very dynamic sun and Earth communications geometries force a unique approach to landing, traverse design and mission operations.

lunar poles↗
NASA NTRS2017

Landing Site and Traverse Plan Development for Resource Prospector

Resource Prospector (RP) will be the first lunar surface robotic expedition to explore the character and feasibility of in situ resource utilization at the lunar poles. It is aimed at determining where, and how much, hydrogen-bearing and other volatiles are sequestered in polar cold traps. To meet its goals, the mission should land where the likelihood of finding polar volatiles is high. The operational environment is challenging: very low sun elevations, long shadows cast by even moderate relief, cryogenic subsurface temperatures, unknown regolith properties, and very dynamic sun and Earth communications geometries force a unique approach to landing, traverse design and mission operations.

Resource Prospector (RP)↗