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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 NTRS1990

Optimal design of a space power system

The aerospace industry, like many other industries, regularly applies optimization techniques to develop designs which reduce cost, maximize performance, and minimize weight. The desire to minimize weight is of particular importance in space-related products since the costs of launch are directly related to payload weight, and launch vehicle capabilities often limit the allowable weight of a component or system. With these concerns in mind, this paper presents the optimization of a space-based power generation system for minimum mass. The goal of this work is to demonstrate the use of optimization techniques on a realistic and practical engineering system. The power system described uses thermoelectric devices to convert heat into electricity. The heat source for the system is a nuclear reactor. Waste heat is rejected from the system to space by a radiator.

Chun, Young W.↗
NASA NTRS2000

Technology Development for a Stirling Radioisotope Power System

NASA Glenn Research Center and the Department of Energy are developing a Stirling convertor for an advanced radioisotope power system to provide spacecraft on-board electric power for NASA deep space missions. NASA Glenn is addressing key technology issues through the use of two NASA Phase II SBIRs with Stirling Technology Company (STC) of Kennewick, WA. Under the first SBIR, STC demonstrated a synchronous connection of two thermodynamically independent free-piston Stirling convertors and a 40 to 50 fold reduction in vibrations compared to an unbalanced convertor. The second SBIR is for the development of an Adaptive Vibration Reduction System (AVRS) that will essentially eliminate vibrations over the mission lifetime, even in the unlikely event of a failed convertor. This paper presents the status and results for these two SBIR projects and also discusses a new NASA Glenn in-house project to provide supporting technology for the overall Stirling radioisotope power system development. Tasks for this new effort include convertor performance verification, controls development, heater head structural life assessment, magnet characterization and thermal aging tests, FEA analysis for a lightweight alternator concept, and demonstration of convertor operation under launch and orbit transfer load conditions.

Thieme, Lanny G.↗
NASA NTRS2011

A Small Fission Power System for NASA Planetary Science Missions

In March 2010, the Decadal Survey Giant Planets Panel (GPP) requested a short-turnaround study to evaluate the feasibility of a small Fission Power System (FPS) for future unspecified National Aeronautics and Space Administration (NASA) science missions. FPS technology was considered a potential option for power levels that might not be achievable with radioisotope power systems. A study plan was generated and a joint NASA and Department of Energy (DOE) study team was formed. The team developed a set of notional requirements that included 1-kW electrical output, 15-year design life, and 2020 launch availability. After completing a short round of concept screening studies, the team selected a single concept for concentrated study and analysis. The selected concept is a solid block uranium-molybdenum reactor core with heat pipe cooling and distributed thermoelectric power converters directly coupled to aluminum radiator fins. This paper presents the preliminary configuration, mass summary, and proposed development program.

Mason, Lee↗
NASA NTRS1991

Lunar electric power systems utilizing the SP-100 reactor coupled to dynamic conversion systems

An integration study was performed by coupling an SP-100 reactor to either a Brayton or Stirling power conversion subsystem. The application was for a surface power system to supply power requirements to a lunar base. A power level of 550 kWe was selected based on the NASA Space Exploration Initiative 90-day study. Reliability studies were initially performed to determine optimum power-conversion redundancy. This study resulted in selecting three operating engines and one standby unit. Integratiaon-design studies indicated that either the Brayton or Stirling power conversion subsystem could be integrated with the SP-100 reactor. The Stirling system had an integration advantage because of smaller piping size and fewer components. The Stirling engine, however, is more complex and heavier than the Brayton rotating unit, which tends to offset the Stirling integration advantage. From a performance consideration, the Brayton had a 9-percent mass advantage and the Stirling a 50-percent radiator-area advantage.

Harty, Richard B.↗
NASA NTRS1988

Space Station power system autonomy demonstration

The Systems Autonomy Demonstration Program (SADP) represents NASA's major effort to demonstrate, through a series of complex ground experiments, the application and benefits of applying advanced automation technologies to the Space Station project. Lewis Research Center (LeRC) and Marshall Space Flight Center (MSFC) will first jointly develop an autonomous power system using existing Space Station testbed facilities at each center. The subsequent 1990 power-thermal demonstration will then involve the cooperative operation of the LeRC/MSFC power system with the Johnson Space Center (JSC's) thermal control and DMS/OMS testbed facilities. The testbeds and expert systems at each of the NASA centers will be interconnected via communication links. The appropriate knowledge-based technology will be developed for each testbed and applied to problems requiring intersystem cooperation. Primary emphasis will be focused on failure detection and classification, system reconfiguration, planning and scheduling of electrical power resources, and integration of knowledge-based and conventional control system software into the design and operation of Space Station testbeds.

Kish, James A.↗
NASA NTRS1988

A simulation model for reliability evaluation of Space Station power systems

A detailed simulation model for the hybrid Space Station power system is presented which allows photovoltaic and solar dynamic power sources to be mixed in varying proportions. The model considers the dependence of reliability and storage characteristics during the sun and eclipse periods, and makes it possible to model the charging and discharging of the energy storage modules in a relatively accurate manner on a continuous basis.

Singh, C.↗
NASA NTRS2005

Exploring Europa with a Surface Lander Powered by a Small Radioisotope Power System (RPS)

This paper describes a conceptual landed mission to the Jovian satellite Europa using a small RPS powered lander that would ride piggyback on the proposed Jupiter Icy Moons Orbiter (JIMO). This mission study was performed to assess the feasibility of landing a realistic science driven payload using a conceptual small radioisotope power system (US) to provide electrical and thermal power during the extended duration cruise phase (up to 13 years) and the nominal 30 day surface science mission. This paper includes individual sections that describe the key science goals, the mission architecture, and the conceptual design of the Europa Lander Mission (ELM) spacecraft.

lander↗
NASA NTRS1986

Long range inhabited surface transportation system power source for the exploration of Mars (manned Mars mission)

A hydrogen-oxygen fuel cell system is identified as a viable power source for a long range inhabited surface transportation system for the exploration of Mars. Power system weights and power requirements are determined as a function of vehicle weight. For vehicles weighing from 2700 to 7300 kg in LEO, the total power system weight ranges from 1140 to 1860 kg, with the reactants and energy conversion hardware (fuel cells, reactant storage, and radiator) weighing 430 to 555 kg and 610 to 1110 kg, respectively. Vehicle power requirements range from 45 kW for a 2700 kg vehicle to 110 kW for a 7300 kg vehicle. Power system specific weights and power profiles for housekeeping and the operation of scientific equipment such as coring drills and power tools are also specified.

Lisa Kohout↗
NASA NTRS2012

Development of a PEMFC Power System with Integrated Balance of Plant

Autonomous Underwater Vehicles (AUV s) have received increasing attention in recent years as military and commercial users look for means to maintain a mobile and persistent presence in the undersea world. Compact, neutrally buoyant power systems are needed for both small and large vehicles. Batteries are usually employed in these applications, but the energy density and therefore the mission duration are limited with current battery technology. At a certain energy or mission duration requirement, other means to get long duration power become feasible. For example, above 10 kW-hrs liquid oxygen and hydrogen have better specific energy than batteries and are preferable for energy storage as long as a compact system of about 100 W/liter is achievable to convert the chemical energy in these reactants into power. Other reactant forms are possible, such as high pressure gas, chemical hydrides or oxygen carriers, but it is essential that the power system be small and light weight. Recent fuel cell work, primarily focused on NASA applications, has developed power systems that can meet this target power density. Passive flow-through systems, using ejector driven reactant (EDR) flow, integrated into a compact balance of plant have been developed. These systems are thermally and functionally integrated in much the same way as are automotive, air breathing fuel cell systems. These systems fit into the small volumes required for AUV and future NASA applications. Designs have been developed for both a 21" diameter and a larger diameter (LD) AUV. These fuel cell systems occupy a very small portion of the overall energy system, allowing most of the system volume to be used for the reactants. The fuel cell systems have been optimized to use reactants efficiently with high stack efficiency and low parasitic losses. The resulting compact, highly efficient fuel cell system provides exceptional reactant utilization and energy density. Key design variables and supporting test data are presented. Future development activities are described.

Wynne, B.↗
NASA NTRS2018

Dynamic Radioisotope Power Systems: Convertor Development at NASA GRC

NASA's dynamic power convertor development in support of high-efficiency RPS is progressing as planned, and shows promise. This presentation gives dynamic conversion power system background, development path, and key convertor performance goals. It also gives information on the Flexure Isotope Stirling Convertor, Turbo-Brayton Convertor, Thermo-Acoustic Power Convertor, Sunpower Robust Stirling Convertor, Stirling Convertor Extended Operation, TDC #14 Disassembly and Inspection, and Launch Vibration Exposure on SES #2.

Oriti, Sal↗
NASA NTRS1985

Reactor power system deployment and startup

This paper addresses issues that should receive further examination in the near-term as concept selection for development of a U.S. space reactor power system is approached. The issues include: the economics, practicality and system reliability associated with transfer of nuclear spacecraft from low earth shuttle orbits to operational orbits, via chemical propulsion versus nuclear electric propulsion; possible astronaut supervised reactor and nuclear electric propulsion startup in low altitude Shuttle orbit; potential deployment methods for nuclear powered spacecraft from Shuttle; the general public safety of low altitude startup and nuclear safe and disposal orbits; the question of preferred reactor power level; and the question of frozen versus molten alkali metal coolant during launch and deployment. These issues must be considered now because they impact the SP-100 concept selection, power level selection, weight and size limits, use of deployable radiators, reliability requirements, and economics, as well as the degree of need for and the urgency of developing space reactor power systems.

Wetch, J. R.↗
NASA NTRS1987

Heat pipe radiators for solar dynamic space power system heat rejection

The paper presents the results of a concept development study of heat rejection systems for Space Station solar dynamic power systems. The thermal performance and weights of each of the heat rejection subsystems have been addressed in detail, and critical technologies which require development tests and evaluation for successful demonstration were assessed and identified. Baseline and several alternate heat rejection system configurations and optimum designs were developed for both Brayton and Rankine cycles. The thermal performance, mass properties, assembly requirements, reliability, maintenance requirements, and life cycle costs were determined for each of the system configurations. Trade studies were performed on each configuration with respect to the heat pipe wall thickness and the amount of redundancy to determine the effects on system reliability, maintenance requirements, and life cycle costs. An optimum design was then selected for each configuration.

Gustafson, Eric↗