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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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All sourcesNASA NTRSDOE OSTI
NASA NTRS2016

Modular Power Standard for Space Explorations Missions

Future human space exploration will most likely be composed of assemblies of multiple modular spacecraft elements with interconnected electrical power systems. An electrical system composed of a standardized set modular building blocks provides significant development, integration, and operational cost advantages. The modular approach can also provide the flexibility to configure power systems to meet the mission needs. A primary goal of the Advanced Exploration Systems (AES) Modular Power System (AMPS) project is to establish a Modular Power Standard that is needed to realize these benefits. This paper is intended to give the space exploration community a "first look" at the evolving Modular Power Standard and invite their comments and technical contributions.

Exploration↗
NASA NTRSDate not supplied

Establishing Electrified Aircraft Propulsion Concepts—How AATT identified viable propulsion concepts and established foundational technologies

In the mid 2000’s NASA challenged the aeronautics industry to identify the routes for achieving ambitious improvements in fuel burn, emission, and noise reductions. These so-called “N+3” studies were exploring broad changes three commercial aircraft generations, or nominally 30 years, in the future. Many intriguing propulsion-airframe integrated solutions were proposed and pursued, which incorporated technologies such as high-aspect-ratio wings, boundary-layer ingestion, and hybrid-electric powertrains. When the Advanced Air Transport Technology (AATT) Project introduced “Technical Challenge 5.2-Establish viable concept for 5-10 MW hybrid gas-electric propulsion system for a commercial transport aircraft” in 2014, industry was very skeptical that electrified propulsion could make a significant impact in commercial air transport over the subsequent 30 years. Yet there were many practical reasons why improvements in electric power system and electric powertrains were advancing at a rapid rate and could lead to paradigm changes in aircraft propulsion. The challenge to the aeronautics community was to discover how to harness this power revolution and apply it to aircraft propulsion. This talk summarizes the approaches and achievements from the Hybrid Gas-Electric Propulsion Concept Technical Challenge that concluded in 2019. The balanced portfolio of concepts studies anchored with practical technology development demonstrated that electrified aircraft propulsion is an aircraft revolution whose time has come.

electric propulsion↗
NASA NTRS1992

Description of the SSF PMAD DC testbed control system data acquisition function

The NASA LeRC in Cleveland, Ohio has completed the development and integration of a Power Management and Distribution (PMAD) DC Testbed. This testbed is a reduced scale representation of the end to end, sources to loads, Space Station Freedom Electrical Power System (SSF EPS). This unique facility is being used to demonstrate DC power generation and distribution, power management and control, and system operation techniques considered to be prime candidates for the Space Station Freedom. A key capability of the testbed is its ability to be configured to address system level issues in support of critical SSF program design milestones. Electrical power system control and operation issues like source control, source regulation, system fault protection, end-to-end system stability, health monitoring, resource allocation, and resource management are being evaluated in the testbed. The SSF EPS control functional allocation between on-board computers and ground based systems is evolving. Initially, ground based systems will perform the bulk of power system control and operation. The EPS control system is required to continuously monitor and determine the current state of the power system. The DC Testbed Control System consists of standard controllers arranged in a hierarchical and distributed architecture. These controllers provide all the monitoring and control functions for the DC Testbed Electrical Power System. Higher level controllers include the Power Management Controller, Load Management Controller, Operator Interface System, and a network of computer systems that perform some of the SSF Ground based Control Center Operation. The lower level controllers include Main Bus Switch Controllers and Photovoltaic Controllers. Power system status information is periodically provided to the higher level controllers to perform system control and operation. The data acquisition function of the control system is distributed among the various levels of the hierarchy. Data requirements are dictated by the control system algorithms being implemented at each level. A functional description of the various levels of the testbed control system architecture, the data acquisition function, and the status of its implementationis presented.

Baez, Anastacio N.↗
NASA NTRS2006

Overview of Small and Large-Scale Space Solar Power Concepts

An overview of space solar power studies performed at the Boeing Company under contract with NASA will be presented. The major concepts to be presented are: 1. Power Plug in Orbit: this is a spacecraft that collects solar energy and distributes it to users in space using directed radio frequency or optical energy. Our concept uses solar arrays having the same dimensions as ISS arrays, but are assumed to be more efficient. If radiofrequency wavelengths are used, it will necessitate that the receiving satellite be equipped with a rectifying antenna (rectenna). For optical wavelengths, the solar arrays on the receiving satellite will collect the power. 2. Mars Clipper I Power Explorer: this is a solar electric Mars transfer vehicle to support human missions. A near-term precursor could be a high-power radar mapping spacecraft with self-transport capability. Advanced solar electric power systems and electric propulsion technology constitute viable elements for conducting human Mars missions that are roughly comparable in performance to similar missions utilizing alternative high thrust systems, with the one exception being their inability to achieve short Earth-Mars trip times. 3. Alternative Architectures: this task involves investigating alternatives to the traditional solar power satellite (SPS) to supply commercial power from space for use on Earth. Four concepts were studied: two using photovoltaic power generation, and two using solar dynamic power generation, with microwave and laser power transmission alternatives considered for each. All four architectures use geostationary orbit. 4. Cryogenic Propellant Depot in Earth Orbit: this concept uses large solar arrays (producing perhaps 600 kW) to electrolyze water launched from Earth, liquefy the resulting hydrogen and oxygen gases, and store them until needed by spacecraft. 5. Beam-Powered Lunar Polar Rover: a lunar rover powered by a microwave or laser beam can explore permanently shadowed craters near the lunar poles to search for water ice and other frozen volatiles. Near such craters are mountain peaks and highlands that are in near permanent sunlight. Power can be beamed from a collector on a sunlit mountain or crater rim to a rover inside a crater. Near-term applications of space solar power technology can therefore pave the way toward large-scale commercial power from space.

Potter, Seth↗
NASA NTRS1986

The Pegasus drive - A multi-megawatt nuclear electric propulsion system

Pegasus, a power generating system for use in space, is multimegawatt power system that would enable missions of almost any conceivable duration and scope. The Pegassus Drive is the coupling of this nuclear electric power system with a 6 MWe MPD thruster. The power system has a maximum power output of 8.5 MWe. The MPD thruster requires 6 MWe to provide spacecraft propulsion and 1.5 MWe are available for mission-specific tasks and experiments. The balance of power generated is used to operate the power system. The size and mass limitations of the STS are of prime consideration in the design of this system to allow the collapsed system to be placed in lower earth orbit by two Shuttle missions. The main system (19,120 kg) employing a shadow shield would require one launch and the balance of the four-pi shield (27,830 kg) would occupy the second launch. Development of this power system could be completed by the mid 1990's and the system available near the turn of the century.

Coomes, E. P.↗
NASA NTRS1980

Application of small-signal modeling and measurement techniques to the stability analysis of an integrated switching-mode power system

Small-signal modeling techniques are used in a system stability analysis of a breadboard version of a complete functional electrical power system. The system consists of a regulated switching dc-to-dc converter, a solar-cell-array simulator, a solar-array EMI filter, battery chargers and linear shunt regulators. Loss mechanisms in the converter power stage, including switching-time effects in the semiconductor elements, are incorporated into the modeling procedure to provide an accurate representation of the system without requiring frequency-domain measurements to determine the damping factor. The small-signal system model is validated by the use of special measurement techniques which are adapted to the poor signal-to-noise ratio encountered in switching-mode systems. The complete electrical power system with the solar-array EMI filter is shown to be stable over the intended range of operation.

Wong, R. C.↗
NASA NTRS2019

A Multiple Model Based Approach for Deep Space Power System Fault Diagnosis

Improving protection and health management capabilities onboard the electrical power system (EPS) for spacecraft is essential for ensuring safe and reliable conditions for deep space human exploration. Electrical protection and control technologies on the National Aeronautics and Space Administration's (NASA's) current human space platform relies heavily on ground support to monitor and diagnose power systems and failures. As communication bandwidth diminishes for deep space applications, a transformation in system monitoring and control becomes necessary to maintain high reliability of electric power service. This paper presents a novel approach for on-line power system security monitoring for autonomous deep space spacecraft.

Autonomous Power Controller↗
NASA NTRS1973

A Reusable Lunar Shuttlecraft (RLS): A systems study

A study effort to conceive and design a reusable lunar space vehicle system was conducted at a university. The purpose of the program was to expose students to the problems faced by other disciplines in the design of a complete vehicle system. The subjects investigated are: (1) objectives, feasibility, and cost of reusable lunar shuttlecraft, (2) trajectory analysis, (3) guidance and navigation, (4) communication system, (5) propulsion system, (6) electrical power system, and (7) landing gear design.

Source record↗
NASA NTRS1992

Design of multi-mission spacecraft bus

This paper presents preliminary design of a multimission spacecraft bus for meteorological and communications payloads. The meteorological payload uses sun-synchronous circular orbit and the communications payload uses Molniya type orbit to provide communications for areas not covered by geosynchronous communications satellites. The launch vehicles are Pegasus for the meteorological payload and Taurus for the communications payload. The spacecraft bus uses three-axis stabilization consisting of a three reaction wheel system. The electric power system consists of single-axis tracking silicon solar array and Ni2 H2 batteries. The propulsion subsystem consists of six hydrazine thrusters and one propellant tank.

Agrawal, Brij N.↗
NASA NTRS2017

A Simulation Based Investigation of High Latency Space Systems Operations

This study was the first in a series of planned tests to use physics-based subsystem simulations to investigate the interactions between a spacecraft's crew and a ground-based mission control center for vehicle subsystem operations across long communication delays. The simulation models the life support system of a deep space habitat. It contains models of an environmental control and life support system, an electrical power system, an active thermal control systems, and crew metabolic functions. The simulation has three interfaces: 1) a real-time crew interface that can be use to monitor and control the subsystems; 2) a mission control center interface with data transport delays up to 15 minute each way; and 3) a real-time simulation test conductor interface used to insert subsystem malfunctions and observe the interactions between the crew, ground, and simulated vehicle. The study was conducted at the 21st NASA Extreme Environment Mission Operations (NEEMO) mission. The NEEMO crew and ground support team performed a number of relevant deep space mission scenarios that included both nominal activities and activities with system malfunctions. While this initial test sequence was focused on test infrastructure and procedures development, the data collected in the study already indicate that long communication delays have notable impacts on the operation of deep space systems. For future human missions beyond cis-lunar, NASA will need to design systems and support tools to meet these challenges. These will be used to train the crew to handle critical malfunctions on their own, to predict malfunctions and assist with vehicle operations. Subsequent more detailed and involved studies will be conducted to continue advancing NASA's understanding of space systems operations across long communications delays.

Li, Zu Qun↗
NASA NTRS2017

A Simulation Based Investigation of High Latency Space Systems Operations

This study was the first in a series of planned tests to use physics-based subsystem simulations to investigate the interactions between a spacecraft's crew and a ground-based mission control center for vehicle subsystem operations across long communication delays. The simulation models the life support system of a deep space habitat. It contains models of an environmental control and life support system, an electrical power system, an active thermal control system, and crew metabolic functions. The simulation has three interfaces: 1) a real-time crew interface that can be use to monitor and control the subsystems; 2) a mission control center interface with data transport delays up to 15 minute each way; and 3) a real-time simulation test conductor interface used to insert subsystem malfunctions and observe the interactions between the crew, ground, and simulated vehicle. The study was conducted at the 21st NASA Extreme Environment Mission Operations (NEEMO) mission. The NEEMO crew and ground support team performed a number of relevant deep space mission scenarios that included both nominal activities and activities with system malfunctions. While this initial test sequence was focused on test infrastructure and procedures development, the data collected in the study already indicate that long communication delays have notable impacts on the operation of deep space systems. For future human missions beyond cis-lunar, NASA will need to design systems and support tools to meet these challenges. These will be used to train the crew to handle critical malfunctions on their own, to predict malfunctions, and to assist with vehicle operations. Subsequent more detailed and involved studies will be conducted to continue advancing NASA's understanding of space systems operations across long communications delays.

Li, Zu Qun↗
NASA NTRSDate not supplied

Extending ISS Life Beyond 2030

This paper presents an overview of the International Space Station life extension project, focusing on the analytical approach used to assess its primary structure. Also addressed are life extension approaches for other affected sub-systems, including secondary structure, materials, Environmental Control and Life Support Systems (ECLSS), Electrical Power Systems (EPS), and Logistics and Maintenance (L&M). The United States On-orbit Segment (USOS) of the International Space Station (ISS) was initially designed for a 15-year on-orbit life, but with the realization of its continued importance, efforts were made to extend its operations through 2030. The paper discusses the various analyses conducted, including future operations planning, load simulation, material degradation studies, thermal analyses, and fracture analyses. The results demonstrate the feasibility and achievability of extending the ISS's life, ensuring its on-going role as a hub for scientific research, international cooperation, and educational endeavors. With the life extension process in place, continuous operations beyond 2030 are possible to maintain an uninterrupted human presence in Low Earth Orbit, facilitating the testing of new technologies, and allow for a seamless transition to new commercially owned and operated destinations.

design life↗
NASA NTRS2006

Sensor Data Qualification for Autonomous Operation of Space Systems

NASA's new Exploration initiative for both robotic and manned missions will require higher levels of reliability, autonomy and reconfiguration capability to make the missions safe, successful and affordable. Future systems will require diagnostic reasoning to assess the health of the system in order to maintain the system s functionality. The diagnostic reasoning and assessment will involve data qualification, fault detection, fault isolation and remediation control. A team of researchers at the NASA Glenn Research Center is currently working on a Sensor Data Qualification (SDQ) system that will support these critical evaluation processes, for both automated and human-in-the-loop applications. Data qualification is required as a first step so that critical safety and operational decisions are based on good data. The SDQ system would monitor a network of related sensors to determine the health of individual sensors within that network. Various diagnostic systems such as the Caution and Warning System would then use the sensor health information with confidence. The proposed SDQ technology will be demonstrated on a variety of subsystems that are relevant to NASA s Exploration systems, which currently include an electrical power system and a cryogenic fluid management system. The focus of this paper is the development and demonstration of a SDQ application for a prototype power distribution unit that is representative of a Crew Exploration Vehicle electrical power system; this provides a unique and relevant environment in which to demonstrate the feasibility of the SDQ technology.

Maul, William A.↗
NASA NTRS1972

Nuclear applications in manned space station

The zirconium hydride reactor, coupled to a thermo-electric or Brayton conversion system, and the Pu 238 isotope/Brayton system, are considered to be the viable nuclear candidates for the modular space station electrical power system. The basic integration aspects of these nuclear electrical power systems are reviewed, including unique requirements imposed by the buildup and incremental utilization considerations of the modular station. Also treated are the various programmatic aspects of nuclear power system design and selection.

Brooksbank, W. A., Jr.↗
NASA NTRS2014

The Use of Software Agents for Autonomous Control of a DC Space Power System

In order to enable manned deep-space missions, the spacecraft must be controlled autonomously using on-board algorithms. A control architecture is proposed to enable this autonomous operation for an spacecraft electric power system and then implemented using a highly distributed network of software agents. These agents collaborate and compete with each other in order to implement each of the control functions. A subset of this control architecture is tested against a steadystate power system simulation and found to be able to solve a constrained optimization problem with competing objectives using only local information.

autonomous control↗
NASA NTRS2014

An Architecture to Enable Autonomous Control of Spacecraft

Autonomy is required for manned spacecraft missions distant enough that light-time communication delays make ground-based mission control infeasible. Presently, ground controllers develop a complete schedule of power modes for all spacecraft components based on a large number of factors. The proposed architecture is an early attempt to formalize and automate this process using on-vehicle computation resources. In order to demonstrate this architecture, an autonomous electrical power system controller and vehicle Mission Manager are constructed. These two components are designed to work together in order to plan upcoming load use as well as respond to unanticipated deviations from the plan. The communication protocol was developed using "paper" simulations prior to formally encoding the messages and developing software to implement the required functionality. These software routines exchange data via TCP/IP sockets with the Mission Manager operating at NASA Ames Research Center and the autonomous power controller running at NASA Glenn Research Center. The interconnected systems are tested and shown to be effective at planning the operation of a simulated quasi-steady state spacecraft power system and responding to unexpected disturbances.

space power systems↗