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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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NASA NTRS2010

Advanced Avionics and Processor Systems for a Flexible Space Exploration Architecture

The Advanced Avionics and Processor Systems (AAPS) project, formerly known as the Radiation Hardened Electronics for Space Environments (RHESE) project, endeavors to develop advanced avionic and processor technologies anticipated to be used by NASA s currently evolving space exploration architectures. The AAPS project is a part of the Exploration Technology Development Program, which funds an entire suite of technologies that are aimed at enabling NASA s ability to explore beyond low earth orbit. NASA s Marshall Space Flight Center (MSFC) manages the AAPS project. AAPS uses a broad-scoped approach to developing avionic and processor systems. Investment areas include advanced electronic designs and technologies capable of providing environmental hardness, reconfigurable computing techniques, software tools for radiation effects assessment, and radiation environment modeling tools. Near-term emphasis within the multiple AAPS tasks focuses on developing prototype components using semiconductor processes and materials (such as Silicon-Germanium (SiGe)) to enhance a device s tolerance to radiation events and low temperature environments. As the SiGe technology will culminate in a delivered prototype this fiscal year, the project emphasis shifts its focus to developing low-power, high efficiency total processor hardening techniques. In addition to processor development, the project endeavors to demonstrate techniques applicable to reconfigurable computing and partially reconfigurable Field Programmable Gate Arrays (FPGAs). This capability enables avionic architectures the ability to develop FPGA-based, radiation tolerant processor boards that can serve in multiple physical locations throughout the spacecraft and perform multiple functions during the course of the mission. The individual tasks that comprise AAPS are diverse, yet united in the common endeavor to develop electronics capable of operating within the harsh environment of space. Specifically, the AAPS tasks for the Federal fiscal year of 2010 are: Silicon-Germanium (SiGe) Integrated Electronics for Extreme Environments, Modeling of Radiation Effects on Electronics, Radiation Hardened High Performance Processors (HPP), and and Reconfigurable Computing.

Keys, Andrew S.↗
NASA NTRS2013

Contemplating Synergistic Algorithms for the NASA ACE Mission

ACE is a proposed Tier 2 NASA Decadal Survey mission that will focus on clouds, aerosols, and precipitation as well as ocean ecosystems. The primary objective of the clouds component of this mission is to advance our ability to predict changes to the Earth's hydrological cycle and energy balance in response to climate forcings by generating observational constraints on future science questions, especially those associated with the effects of aerosol on clouds and precipitation. ACE will continue and extend the measurement heritage that began with the A-Train and that will continue through Earthcare. ACE planning efforts have identified several data streams that can contribute significantly to characterizing the properties of clouds and precipitation and the physical processes that force these properties. These include dual frequency Doppler radar, high spectral resolution lidar, polarimetric visible imagers, passive microwave and submillimeter wave radiometry. While all these data streams are technologically feasible, their total cost is substantial and likely prohibitive. It is, therefore, necessary to critically evaluate their contributions to the ACE science goals. We have begun developing algorithms to explore this trade space. Specifically, we will describe our early exploratory algorithms that take as input the set of potential ACE-like data streams and evaluate critically to what extent each data stream influences the error in a specific cloud quantity retrieval.

precipitation↗
NASA NTRS2017

Marshall Space Flight Center Technology Capabilities for Use in Space Situational Awareness Activities

Marshall performs research, integrates information, matures technologies, and enhances science to bring together a diverse portfolio of products and services of interest for Space Situational Awareness (SSA) and Space Asset Management (SAM), all of which can be accessed through partnerships with Marshall. Integrated Space Situational Awareness and Asset Management (ISSAAM) is an initiative of NASA's Marshall Space Flight Center to improve space situational awareness and space asset management through technical innovation, collaboration, and cooperation with U.S. Government agencies and the global space community. Marshall Space Flight Center provides solutions for complex issues with in-depth capabilities, a broad range of experience, and expertise unique in the world, and all available in one convenient location. NASA has longstanding guidelines that are used to assess space objects. Specifically, Marshall Space Flight Center has the capabilities, facilities and expertise to address the challenges that space objects, such as near-Earth objects (NEO) or Orbital Debris pose. ISSAAM's three pronged approach brings together vital information and in-depth tools working simultaneously toward examining the complex problems encountered in space situational awareness. Marshall's role in managing, understanding and planning includes many projects grouped under each prong area: Database/Analyses/Visualization; Detection/Tracking/ Mitigation/Removal. These are not limited to those listed below.

Gagliano, Larry↗
NASA NTRS2020

Assessment of Extremes in Global Precipitation Products: How Reliable Are They?

Global gridded precipitation products have proven essential for many applications ranging from hydrological modeling and climate model validation to natural hazard risk assessment. They provide a global picture of how precipitation varies across time and space, specifically in regions where ground-based observations are scarce. While the application of global precipitation products has become widespread, there is limited knowledge on how well these products represent the magnitude and frequency of extreme precipitation—the key features in triggering flood hazards. Here, five global precipitation datasets (MSWEP, CFSR, CPC, PERSIANN-CDR, and WFDEI) are compared to each other and to surface observations. The spatial variability of relatively high precipitation events (tail heaviness) and the resulting discrepancy among datasets in the predicted precipitation return levels were evaluated for the time period 1979–2017. The analysis shows that 1) these products do not provide a consistent representation of the behavior of extremes as quantified by the tail heaviness, 2) there is strong spatial variability in the tail index, 3) the spatial patterns of the tail heaviness generally match the Köppen–Geiger climate classification, and 4) the predicted return levels for 100 and 1000 years differ significantly among the gridded products. More generally, our findings reveal shortcomings of global precipitation products in representing extremes and highlight that there is no single global product that performs best for all regions and climates.

Risk assessment↗
NASA NTRSDate not supplied

Mechanical Unloading Effects Hematopoiesis and Subsequent Red Blood Cell Life Cycle Evaluated at Singe Cell Resolution

Red blood cell formation or erythropoiesis in the bone marrow and exit into circulation are known to be affected by mechanical loading. Specifically, space anemia is a condition observed during prolonged microgravity unloading in which the red blood cell (RBC) mass in circulation is reduced. However, the mechanisms causing space anemia are yet to be clearly established, but may include increased hemolysis of RBC in circulation, decreased RBC production or a combination of both factors. The presentation of space anemia is comparable to chronic anemia conditions associated with aging, disuse, and poor health. Molecular dysregulation in the RBC's life cycle is poorly defined and is a significant concern in the context of disuse anemia as mechanotransduction significantly alters of gene expression, protein synthesis and cell signaling pathways. Our study analyzes mouse single cell RNA sequencing libraries from the bone marrow, circulating blood, and spleen and integrates the RBC lineage populations from the tissues into a RBC life cycle atlas. This study also probes how age at time of spaceflight contributes to the molecular signature of space anemia. The overarching objective of the study is to develop a mechanistic understanding of space anemia and translate the findings to a better understanding of aging, disuse, and poor health-related anemia to defining the role of mechanical loading in health and devise potential therapeutic interventions. Important findings of our study are: 1) that mechanical unloading in microgravity alters the proportion of developmental RBC lineage cells, skewing toward progenitor, indicating that fewer RBCs may be present in blood; 2) that late reticulocyte number is elevated in the bone marrow of older animals, suggesting a failure to enter circulation; and 3) that the molecular signature of the circulating RBCs is not significantly altered in microgravity. However, expression markers for eryptosis and erythrophagocytosis are elevated in circulating and spleen RBCs, suggesting spaceflight may shorten the lifetime of RBCs after exit from the marrow. In conclusion our results suggest early stages of erythropoiesis proliferation and differentiation in the marrow are key factors in space anemia and mechanical loading may be a necessary step of RBC entry in circulation.

blood↗
NASA NTRS2009

Security Analysis of DTN Architecture and Bundle Protocol Specification for Space-Based Networks

A Delay-Tolerant Network (DTN) Architecture (Request for Comment, RFC-4838) and Bundle Protocol Specification, RFC-5050, have been proposed for space and terrestrial networks. Additional security specifications have been provided via the Bundle Security Specification (currently a work in progress as an Internet Research Task Force internet-draft) and, for link-layer protocols applicable to Space networks, the Licklider Transport Protocol Security Extensions. This document provides a security analysis of the current DTN RFCs and proposed security related internet drafts with a focus on space-based communication networks, which is a rather restricted subset of DTN networks. Note, the original focus and motivation of DTN work was for the Interplanetary Internet . This document does not address general store-and-forward network overlays, just the current work being done by the Internet Research Task Force (IRTF) and the Consultative Committee for Space Data Systems (CCSDS) Space Internetworking Services Area (SIS) - DTN working group under the DTN and Bundle umbrellas. However, much of the analysis is relevant to general store-and-forward overlays.

Ivancic, William D.↗
NASA NTRS2002

Mission Analysis for High Specific Impulse Deep Space Exploration

This paper describes trajectory calculations for high specific impulse engines. Specific impulses on the order of 10,000 to 100,000 sec are predicted in a variety of fusion powered propulsion systems. This paper and its companion paper seek to build on analyses in the literature to yield an analytical routine for determining time of flight and payload fraction to a predetermined destination. The companion paper will compare the results of this analysis to the trajectories determined by several trajectory codes. The major parameters that affect time of flight and payload fraction will be identified and their sensitivities quantified. A review of existing fusion propulsion concepts and their capabilities will also be tabulated.

Adams, Robert B.↗
NASA NTRS2009

Production of Solar Cells in Space from Non Specific Ores by Utilization of Electronically Enhanced Sputtering

An ideal method of construction in space would utilize some form of the Universal Differentiator and Universal Constructor as described by Von Neumann (1). The Universal Differentiator is an idealized non ore specific extractive device which is capable of breaking any ore into its constituent elements, and the Universal Constructor can utilize these elements to build any device with controllability to the nanometer scale. During the Human Exploration Initiative program in the early 1990s a conceptual study was done (2) to understand whether such devices were feasible with near term technology for the utilization of space resources and energy. A candidate system was proposed which would utilize electronically enhanced sputtering as the differentiator. Highly ionized ions would be accelerated to a kinetic energy at which the interaction between them and the lattice elections in the ore would be at a maximum. Experiments have shown that the maximum disintegration of raw material occurs at an ion kinetic energy of about 5 MeV, regardless of the composition and structure of the raw material. Devices that could produce charged ion beams in this energy range in space were being tested in the early 1990s. At this energy, for example an ion in a beam of fluorine ions yields about 8 uranium ions from uranium fluoride, 1,400 hydrogen and oxygen atoms from ice, or 7,000 atoms from sulfur dioxide ice. The ions from the disintegrated ore would then be driven by an electrical field into a discriminator in the form of a mass spectrometer, where the magnetic field would divert the ions into collectors for future use or used directly in molecular beam construction techniques. The process would require 10-7 Torr vacuum which would be available in space or on the moon. If the process were used to make thin film silicon solar cells (ignoring any energy inefficiency for beam production), then energy break even for solar cells in space would occur after 14 days.

Curreri, Peter A.↗
NASA NTRS2010

Environmental Impact Specification for Direct Space Weathering of Kuiper Belt and Oort Cloud Objects

The Direct Space Weathering Project of NASA's Outer Planets Research Program addresses specification of the plasma and energetic particle environments for irradiation and surface chemical processing of icy bodies in the outer solar system and the local interstellar medium. Knowledge of the radiation environments is being expanded by ongoing penetration of the twin Voyager spacecraft into the heliosheath boundary region of the outer heliosphere and expected emergence within the next decade into the very local interstellar medium. The Voyager measurements are being supplemented by remote sensing from Earth orbit of energetic neutral atom emission from this boundary region by NASA's Interstellar Boundary Explorer (IBEX). Although the Voyagers long ago passed the region of the Classical Kuiper Belt, the New Horizons spacecraft will encounter Pluto in 2015 and thereafter explore one or more KBOs, meanwhile providing updated measurements of the heliospheric radiation environment in this region. Modeling of ion transport within the heliosphere allows specification of time-integrated irradiation effects while the combination of Voyager and IBEX data supports projection of the in-situ measurements into interstellar space beyond the heliosheath. Transformation of model ion flux distributions into surface sputtering and volume ionization profiles provides a multi-layer perspective for space weathering impact on the affected icy bodies and may account for some aspects of color and compositional diversity. Other important related factors may include surface erosion and gardening by meteoritic impacts and surface renewal by cryovolcanism. Chemical products of space weathering may contribute to energy resources for the latter.

Cooper, John F.↗
NASA NTRS2002

Trajectories for High Specific Impulse High Specific Power Deep Space Exploration

Preliminary results are presented for two methods to approximate the mission performance of high specific impulse high specific power vehicles. The first method is based on an analytical approximation derived by Williams and Shepherd and can be used to approximate mission performance to outer planets and interstellar space. The second method is based on a parametric analysis of trajectories created using the well known trajectory optimization code, VARITOP. This parametric analysis allows the reader to approximate payload ratios and optimal power requirements for both one-way and round-trip missions. While this second method only addresses missions to and from Jupiter, future work will encompass all of the outer planet destinations and some interstellar precursor missions.

Polsgrove, T.↗
NASA NTRS1984

Development of standardized specifications for screening space level integrated circuits and semiconductors

Standardized methods are established for screening of JAN B microcircuits and JANTXV semiconductor components for space mission or other critical applications when JAN S devices are not available. General specifications are provided which outline the DPA (destructive physical analysis), environmental, electrical, and data requirements for screening of various component technologies. This standard was developed for Air Force Space Division, and is available for use by other DOD agencies, NASA, and space systems contractors for establishing common screening methods for electronic components.

Source record↗
NASA NTRS1985

Space Station crew interface specifications and standards

NASA's Space Station Human Productivity and Man/System Integration Standards programs are described. The data collection methodologies and analyses utilized in the productivity study are examined. The study reveals that attention to habitability is required in order to maximize human productivity for on-orbit operations. The nine program tasks used to develop standards for man/system integration are discussed.

Geer, C. W.↗
NASA NTRS2002

Trajectories for High Specific Impulse High Specific Power Deep Space Exploration

Flight times and deliverable masses for electric and fusion propulsion systems are difficult to approximate. Numerical integration is required for these continuous thrust systems. Many scientists are not equipped with the tools and expertise to conduct interplanetary and interstellar trajectory analysis for their concepts. Several charts plotting the results of well-known trajectory simulation codes were developed and are contained in this paper. These charts illustrate the dependence of time of flight and payload ratio on jet power, initial mass, specific impulse and specific power. These charts are intended to be a tool by which people in the propulsion community can explore the possibilities of their propulsion system concepts. Trajectories were simulated using the tools VARITOP and IPOST. VARITOP is a well known trajectory optimization code that involves numerical integration based on calculus of variations. IPOST has several methods of trajectory simulation; the one used in this paper is Cowell's method for full integration of the equations of motion. An analytical method derived in the companion paper was also evaluated. The accuracy of this method is discussed in the paper.

Polsgrove, Tara↗
NASA NTRS2002

Simulation of Trajectories for High Specific Impulse Deep Space Exploration

Difficulties in approximating flight times and deliverable masses for continuous thrust propulsion systems have complicated comparison and evaluation of proposed propulsion concepts. These continuous thrust propulsion systems are of interest to many groups, not the least of which are the electric propulsion and fusion communities. Several charts plotting the results of well-known trajectory simulation codes were developed and are contained in this paper. These charts illustrate the dependence of time of flight and payload ratio on jet power, initial mass, specific impulse and specific power. These charts are intended to be a tool by which people in the propulsion community can explore the possibilities of their propulsion system concepts. Trajectories were simulated using the tools VARITOP and IPOST. VARITOP is a well known trajectory optimization code that involves numerical integration based on calculus of variations. IPOST has several methods of trajectory simulation; the one used in this paper is Cowell's method for full integration of the equations of motion. The analytical method derived in the companion paper was also used to simulate the trajectory. The accuracy of this method is discussed in the paper.

Polsgrove, Tara↗
NASA NTRS1992

Linear polarization sensitivity specifications for space-borne instruments

The radiometric accuracy of space-borne instruments such as radiometers and spectroradiometers which make measurements of the earth and other celestial objects can be compromised by the linear polarization sensitivity (LPS) induced by the optical system. Most of these optical systems contain optical elements whose reflectance or transmission is polarization dependent, such as diffraction gratings, folding and scanning mirrors, dichroic filters, and optical fibers. Optical system incorporating such elements generally display linear polarization sensitivity; different linear polarization states incident with equal radiometric power will be measured as different power levels. If the incident polarization state is unknown, the linear polarization sensitivity cannot be compensated during the data reduction. The light reflected from the earth and other planets and moons is usually partially linearly polarized, but in a random distribution. Thus, to make accurate radiometric measurements of these bodies, a radiometer or spectrometer should have a low level of linear polarization sensitivity. This paper contains a mathematical description of LPS, contains references to systems which have imposed a LPS specification, describes some of the sources of LPS, describes how to model LPS by polarization ray tracing, and discusses methods to reduce the LPS of an optical system.

Maymon, Peter W.↗