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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 415 records · Page 23
All sourcesNASA NTRSDOE OSTI
NASA NTRS1981

The in-flight performance of the Solar Maximum Mission Electrical Power System

Circuitry, power handling, and operational characteristics and anomalies of the Electrical Power System (EPS) of the Solar Maximum Mission are discussed. The EPS is designed as a standard unit to be a candidate for use on future space missions. Blown, improperly derated fuses in the Attitude Control System and the Signal Conditioning Assembly have led to switching to magnetrons for solar angle, with a loss of accuracy, and a loss of one-half of telemetry data, respectively. In addition, reasons for an 11-14% degradation of solar array output are uncertain due to the loss of precise attitude control. Current surges to peak at 76.5 A (down from 94.5 A) at sunrise, stays for four to five minutes, then resumes nominal output for the remainder of the 61-68 daytime period. Eclipse varies between 28 and 35 minutes, with corresponding depth of discharge of 14%. The batteries charge at 20 A, and although an overcharge mode has been continuously sensed, operation has been normal and temperature sensors have not indicated overcharge; cell failure has also not been sensed. The system has a two year design life and a desired life of four years.

Broderick, R. J.↗
NASA NTRS1981

Control of new energy sources in an electric utility system

The addition of generators based on renewable resources to the electric power system brings new problems of control and communication if the generators are to be controlled as an integrated part of the power system. Since many of these generators are small, it will require a large number of them, connected to the distribution system, to represent an appreciable fraction of the total generation. This situation contrasts with present day generation control which typically involves only the control of a small number of large generators. This paper examines the system requirements for integrated control, and proposes a control arrangement in which the incremental cost of power is an important parameter.

Kirkham, H.↗
NASA NTRS1991

MOLFLUX analysis of the SSF electrical power system contamination

The external induced contamination of Space Station Freedom's electrical power system surfaces is assessed using a molecular flow evaluation code, MOLFLUX. Outgassing rates are compared to available experimental data, and deposition to the midregion of both the solar array and the photovoltaic power module thermal control system radiator is calculated using a constant sticking coefficient. An estimate of annual deposition to the solar array due to outgassing is found to be 10 percent of the Space Station Freedom program requirement for maximum allowable deposition, while annual deposition to the radiator is approximately equal to the requirement.

Cognion, Rita L.↗
NASA NTRS1994

Electric power system test and verification program

Space Station Freedom's (SSF's) electric power system (EPS) hardware and software verification is performed at all levels of integration, from components to assembly and system level tests. Careful planning is essential to ensure the EPS is tested properly on the ground prior to launch. The results of the test performed on breadboard model hardware and analyses completed to date have been evaluated and used to plan for design qualification and flight acceptance test phases. These results and plans indicate the verification program for SSF's 75-kW EPS would have been successful and completed in time to support the scheduled first element launch.

Rylicki, Daniel S.↗
NASA NTRS1989

Evolutionary growth for Space Station Freedom electrical power system

Over an operational lifetime of at least 30 yr, Space Station Freedom will encounter increased space station user requirements and advancing technologies. The space station electrical power system is designed with the flexibility to accommodate these emerging technologies and expert systems and is being designed with the necessary software hooks and hardware scars to accommodate increased growth demand. The electrical power system is planned to grow from the initial 75 kW up to 300 kW. The Phase 1 station will utilize photovoltaic arrays to produce the electrical power; however, for growth to 300 kW, solar dynamic power modules will be utilized. Pairs of 25 kW solar dynamic power modules will be added to the station to reach the power growth level. The addition of solar dynamic power in the growth phase places constraints in the initial space station systems such as guidance navigation and control, external thermal, truss structural stiffness, computational capabilities and storage which must be planned-in in order to facilitate the addition of the solar dynamic modules.

Marshall, Matthew F.↗
NASA NTRS1989

Evolutionary growth for Space Station Freedom electrical power system

Over an operational lifetime of at least 30 yr, Space Station Freedom will encounter increased Space Station user requirements and advancing technologies. The Space Station electrical power system is designed with the flexibility to accommodate these emerging technologies and expert systems and is being designed with the necessary software hooks and hardware scars to accommodate increased growth demand. The electrical power system is planned to grow from the initial 75 kW up to 300 kW. The Phase 1 station will utilize photovoltaic arrays to produce the electrical power; however, for growth to 300 kW, solar dynamic power modules will be utilized. Pairs of 25 kW solar dynamic power modules will be added to the station to reach the power growth level. The addition of solar dynamic power in the growth phase places constraints in the initial Space Station systems such as guidance, navigation, and control, external thermal, truss structural stiffness, computational capabilities and storage, which must be planned-in, in order to facilitate the addition of the solar dynamic modules.

Marshall, Matthew Fisk↗
DOE OSTI2021

Surface Charge Distribution Mapping Using an Electrostatic Probe

Undesired accumulation of charge on dielectric materials causing electrostatic discharges can be an issue in pulsed power systems and electrical systems in general. As such, an understanding of surface charge distribution, charge accumulation, and decay is required. An in-house no-contact electrostatic probe designed with a 2 mm resolution was fabricated to measure and map surface charge distribution. Designed as a contactless instrument, the probe consisting of a metal rod and low leakage amplifier circuit probes the electric potential near the surface. A scan of the surface then provides the raw data, a potential distribution. The actual probe response - i.e., the surface charge to voltage transfer function, is accounted for in post-processing. This is accomplished via an Inverse Wien Filter - a technique often applied in image processing - to deconvolve the probe response from the measured data. A commercially available electrostatic probe, the Trek 341B meter with a 3455ET probe, capable of measuring +/- 20 kV was compared to the in- house probe that is designed to cover a wider range from +/- 35 kV. A resolution better than the simple probe resolution is achieved through the distribution’s scanning voltage method and deconvolution. Applying repeated scans, surface charge decay was tracked on various polymer materials to determine the material and environment dependence; materials included were PA6, PTFE, and others. As an example of material dependence, samples charged to 20 kV at 65% humidity experience full charge decay in approximately 45 seconds for PA5 (152 mm dia.), while it took about 100 times longer for PTFE (51 mm dia.) to observe the same decay/redistribution of charge.

36 MATERIALS SCIENCE↗
NASA NTRS2016

Proposal and Development of a High Voltage Variable Frequency Alternating Current Power System for Hybrid Electric Aircraft

The development of ultra-efficient commercial vehicles and the transition to low-carbon emission propulsion are seen as thrust paths within NASA Aeronautics. A critical enabler to these paths comes in the form of hybrid-electric propulsion systems. For megawatt-class systems, the best power system topology for these hybrid-electric propulsion systems is debatable. Current proposals within NASA and the Aero community suggest using a combination of AC and DC for power transmission. This paper proposes an alternative to the current thought model through the use of a primarily high voltage AC power generation, transmission, and distribution systems, supported by the Convergent Aeronautics Solutions (CAS) Project. This system relies heavily on the use of dual-fed induction machines, which provide high power densities, minimal power conversion, and variable speed operation. The paper presents background on the project along with the system architecture, development status and preliminary results.

Propulsion↗
NASA NTRS2005

Electric Propulsion System Modeling for the Proposed Prometheus 1 Mission

The proposed Prometheus 1 spacecraft would utilize nuclear electric propulsion to propel the spacecraft to its ultimate destination where it would perform its primary mission. As part of the Prometheus 1 Phase A studies, system models were developed for each of the spacecraft subsystems that were integrated into one overarching system model. The Electric Propulsion System (EPS) model was developed using data from the Prometheus 1 electric propulsion technology development efforts. This EPS model was then used to provide both performance and mass information to the Prometheus 1 system model for total system trades. Development of the EPS model is described, detailing both the performance calculations as well as its evolution over the course of Phase A through three technical baselines. Model outputs are also presented, detailing the performance of the model and its direct relationship to the Prometheus 1 technology development efforts. These EP system model outputs are also analyzed chronologically showing the response of the model development to the four technical baselines during Prometheus 1 Phase A.

Fiehler, Douglas↗
DOE OSTI2025

Valuing the Future Electric Grid: A Bid-Based Approach

Energy storage resources (ESRs) and other zero marginal cost (ZMC) resources have unique characteristics that are not fully captured in today’s electricity planning and operations modeling tools. Because the modeling assumptions used in these tools are simplified approximations of how operations and investment decisions occur in the real-world, accurately representing cost and operational characteristics are key for determining how these resources impact price formation. Questions such as—Where should we build new transmission? Will a small modular reactor earn enough revenue to participate in the future electric grid? Is retrofitting a coal plant with carbon capture technology economically feasible?—all require accurate electricity prices, which aren’t available from today’s electricity planning and operations modeling tools. As an example, production cost models (PCMs) are heavily utilized tools that determine the cost and reliability of the electric system. However, as PCMs were developed to help thermal generators manage their fuel inventories, production cost modeling is largely based on fuel prices. Because ESRs do not incur fuel costs, they are often modeled as ZMC resources. In reality, ESRs incur opportunity costs as well as technology-specific (degradation) costs that are non-trivial to calculate but are important for price formation. In this research, we identify options to incorporate more realistic opportunity and degradation costs in ESR bidding algorithms. Expanding available bidding assumptions allows energy system modelers to develop more accurate economic valuations for ESRs, leading to more accurate price formation from leading energy system modeling tools.

24 POWER TRANSMISSION AND DISTRIBUTION↗
NASA NTRS1974

MSFC Skylab airlock module, volume 1

The history and development of the Skylab Airlock Module and Payload Shroud is presented from initial concept through final design. A summary is given of the Airlock features and systems. System design and performance are presented for the Spent Stage Experiment Support Module, structure and mechanical systems, mass properties, thermal and environmental control systems, EVA/IVA suite system, electrical power system, sequential system, sequential system, and instrumentation system.

Source record↗
NASA NTRS1977

NASA's standard spacecraft for free flying shuttle payloads

The paper gives a detailed description of the Multimission Modular Spacecraft. Attention is given to the structural system, the electrical system, the thermal control system, the power system, attitude control, the propulsion module, and mission considerations.

Bartlett, R. O.↗
NASA NTRS1982

Communications satellite no. 2 (CS-2)

The purpose of the Japanese CS-2 satellite is to provide national communications and industrial communications, such as special emergency and remote communications, and to contribute to the development of technology pertaining to communications satellites. Description and operating parameters of the following satellite components are presented: structure, communications system, telemetry/command system, electric power system, attitude and antenna control system, secondary propulsion system, apogee motor, framework, and heat control system.

Source record↗
NASA NTRS1982

Shuttle operational expectations

The results of orbital flight tests (OFT) of the Space Shuttle are reviewed, and modifications planned for upcoming operational flights are discussed. The performance of the solid rocket boosters, external tank, main engines, structural system, propulsion system, reaction control system, electric power system, heat rejection system, hydraulic system, avionics, and other systems is described and evaluated as generally highly satisfactory. Payload servicing and deployment were also successfully demonstrated by OFT. Additional facilities planned for the operational flights are briefly described, and improvements that will make the Challenger spacecraft lighter than Columbia, provide it with more thrust, and give it a larger payload are summarized. Some software modifications being introduced are also mentioned.

Abrahamson, J. A.↗
NASA NTRS1984

Arc discharge convection studies: A Space Shuttle experiment

Three mercury vapor arc lamps were tested in the microgravity environment of one of NASA's small, self-contained payloads during STS-41B. A description of the payload structural design, photographic and optical systems, and electrical system is provided. Thermal control within the payload is discussed. Examination of digital film data indicates that the 175 watt arc lamp has a significant increase in light output when convection is removed in the gravity-free environment of space.

Bellows, A. H.↗