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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 685 records · Page 38
All sourcesNASA NTRSDOE OSTI
NASA NTRSDate not supplied

Bridging Opportunity Gaps Through Professional Development

Here we describe our progress on building informed professional development resources for students in the planetary sciences. The resources have been instituted within the Lunar and Planetary Institute’s Summer Internship Program.

E G Rivera-valentin↗
NASA NTRS2022

Mind-the-Gap - Part 3: Doppler Velocity Measurements From Space

Convective motions and hydrometeors microphysical properties are highly sought-after parameters for evaluating atmospheric numerical models. With most of the Earth’s surface covered by water, space-borne Doppler radars are ideal for acquiring such measurements at a global scale. While these systems have proven to be useful tools for retrieving cloud microphysical and dynamical properties from the ground, their adequacy, and specific requirements for spaceborne operation still need to be evaluated. Comprehensive forward simulations enable us to assess the advantages and drawbacks of six different Doppler radar architectures currently planned or under consideration by space agencies for the study of cloud dynamics. Radar performance is examined against state-of-the-art numerical model simulations of well-characterized shallow and deep, continental, and oceanic convective cases. Mean Doppler velocity (MDV) measurements collected at multiple frequencies (13, 35 and 94 GHz) provide complementary information in deep convective cloud systems. The high penetration capability of the 13-GHz radar enables to obtain a complete, albeit horizontally under-sampled, view of deep convective storms. The smaller instantaneous field of view (IFOV) of the 35-GHz radar captures more precise information about the location and size of convective updrafts above 5-8 km height of most systems which was determined is the portion of storms where the mass flux peak is typically located. Finally, the lower mean Doppler velocity uncertainty of displaced phase center antenna (DPCA) radars makes them an ideal system for studying microphysics in shallow convection and frontal systems, as well as ice and mixed-phase clouds. It is demonstrated that a 94-GHz DCPA system can achieve retrieval errors as low as 0.05-0.15 mm for raindrop volume-weighted mean diameter and 25% for rime fraction (for a -10 dBZ echo).

Pavlos Kollias↗
NASA NTRSDate not supplied

Reanalysis of Rat Data from Spacelab Life Sciences 2 (SLS-2) to Reveal Research Gaps in Spaceflight Data

Using and analyzing the legacy data obtained in space life sciences missions has the potential to provide researchers a complete picture of the molecular changes associated with space without further experimentation. This project’s objective is to extract, filter, organize, and analyze all Rattus norvegicus data and metadata obtained from Columbia’s Spacelab Life Sciences 2 (SLS-2, STS-58) mission to explore the ways that we can compile information from model organisms, in our case rats, to create a reliable model to understand biological mechanisms in response to these space flight changes. By reusing rare space legacy data coupled with data analysis techniques, we can combine individual preexisting datasets with current ones to gain new, comprehensive insights about the effects of spaceflight on our bodies. Our methods can also lead to the creation of a standardized pipeline that could be applied to other space life science datasets for analysis. In this review, every biological experiment conducted on rats in the SLS-2 Mission was studied with our pipeline to create a new biological library and model that could be used by scientists from around the world to make novel discoveries and develop new hypotheses from this priceless information without the limitation of the costs of spaceflight experimentation.

rats↗
NASA NTRS2022

Understanding the Properties, Wave Drivers, and Impacts of Electron Microburst Precipitation: Current Understanding and Critical Knowledge Gaps

Microbursts are impulsive (~100ms) injections of very energetic to relativistic electrons (energies from a few keV to MeV) into Earth’s atmosphere. Microbursts are important because they may represent a major loss process for the outer radiation belt (Ripoll et al., 2020). Understanding and quantifying the underlying causes and consequences plus relative importance of microburst precipitation represent outstanding questions in radiation belt physics and may have significant implications ranging from space weather to atmospheric chemistry. Chorus waves are the likely dominant cause of microburst precipitation, but important questions remain regarding the exact nature of the resonance generating the microbursts and the overall importance of the precipitation. These important questions are limited by lack of systematic coordination of simultaneous observations of causative waves in the magnetosphere and resulting precipitating particles at low altitudes. Increased funding for multi-spacecraft missions dedicated to answering these questions is critical.

Sadie Elliott↗
NASA NTRSDate not supplied

CFD Simulations of the IHF 13-Inch Nozzle Flow: 55° Sphere-Cone Model, Manufactured Fences and Gaps

Introduction to Arc-Jets and Testing - Arc-jets are primary facilities to test the performance of thermal protection systems (TPS) in an aerothermodynamic heating environment - Free jet test configuration with stagnation coupon or wedge models—conical nozzles - Semi-free jet test configuration with panel test articles—semi-elliptical nozzles A large-scale sphere-cone model, though similar to stagnation models, enables testing TPS materials in combinations of heat flux, pressure and shear different from those accessible in various stagnation and wedge tests

Arc-jets↗