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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 397 records · Page 22

Lot-to-lot Variability of BN Grades for Space Electric Propulsion Applications

Historically, several grades of hot pressed hexagonal boron nitride have been used for space electric propulsion applications. This study investigates the material properties of a selection of commercially available boron nitride grades including HP, M26, M, BNXX, and Shapal Hi-M. This work complements data which was presented at JANNAF 2018. The grades selected for this study are of interest because their available billet size is sufficient for space electric propulsion. This research investigates a range of material properties, tailored and focused on enhancing performance, reliability, and economics of electric propulsion thrusters. This work builds upon previous efforts by studying lot-to-lot variability of some of the properties of interest. Coefficient of friction, moisture absorption, moisture sensitivity, hot press directionality, flexural strength, compression strength, elastic modulus, thermal conductivity, thermal emissivity, thermal expansion, density, X-ray diffraction phase, microstructure, and chemical composition were all investigated across two lots of materials to help guide the selection of advanced ceramics. Variability between lots is the critical concern of the study.

Mackey, Jonathan A.↗

Lunar He-3, fusion propulsion, and space development

The recent identification of a substantial lunar resource of the fusion energy fuel He-3 may provide the first terrestrial market for a lunar commodity and, therefore, a major impetus to lunar development. The impact of this resource-when burned in D-He-3 fusion reactors for space power and propulsion-may be even more significant as an enabling technology for safe, efficient exploration and development of space. One possible reactor configuration among several options, the tandem mirror, illustrates the potential advantages of fusion propulsion. The most important advantage is the ability to provide either fast, piloted vessels or high-payload-fraction cargo vessels due to a range of specific impulses from 50 sec to 1,000,000 sec at thrust-to-weight ratios from 0.1 to 5x10(exp -5). Fusion power research has made steady, impressive progress. It is plausible, and even probable, that fusion rockets similar to the designs presented here will be available in the early part of the twenty-first century, enabling a major expansion of human presence into the solar system.

Santarius, John F.↗

Space station propulsion technology

The objectives of this program are to provide a demonstration of hydrogen/oxygen propulsion technology readiness for the initial operational capability (IOC) space station application, specifically gaseous hydrogen/oxygen and warm hydrogen thruster concepts, and to establish a means for evolving from the IOC space station propulsion system (SSPS) to that required to support and interface with advanced station functions. These objectives were met by analytical studies and by furnishing a propulsion test bed to the Marshall Space Flight Center for testing.

Norman, A. M.↗

A Flight Demonstration of Plasma Rocket Propulsion

The Advanced Space Propulsion Laboratory at the Johnson Space Center has been engaged in the development of a magneto-plasma rocket for several years. This type of rocket could be used in the future to propel interplanetary spacecraft. One advantageous feature of this rocket concept is the ability to vary its specific impulse so that it can be operated in a mode which maximizes propellant efficiency or a mode which maximizes thrust. This presentation will describe a proposed flight experiment in which a simple version of the rocket will be tested in space. In addition to the plasma rocket, the flight experiment will also demonstrate the use of a superconducting electromagnet, extensive use of heat pipes, and possibly the transfer of cryogenic propellant in space.

Petro, Andrew↗

A Flight Demonstration of Plasma Rocket Propulsion

The Advanced Space Propulsion Laboratory at the NASA Johnson Space Center has been engaged in the development of a variable specific impulse magnetoplasma rocket (V ASIMR) for several years. This type of rocket could be used in the future to propel interplanetary spacecraft and has the potential to open the entire solar system to human exploration. One feature of this propulsion technology is the ability to vary its specific impulse so that it can be operated in a mode that maximizes propellant efficiency or a mode that maximizes thrust. Variation of specific impulse and thrust enhances the ability to optimize interplanetary trajectories and results in shorter trip times and lower propellant requirements than with a fixed specific impulse. In its ultimate application for interplanetary travel, the VASIMR would be a multi-megawatt device. A much lower power system is being designed for demonstration in the 2004 timeframe. This first space demonstration would employ a lO-kilowatt thruster aboard a solar powered spacecraft in Earth orbit. The 1O-kilowatt V ASIMR demonstration unit would operate for a period of several months with hydrogen or deuterium propellant with a specific impulse of 10,000 seconds.

Petro, Andrew↗

Use of Human Computer Models to Influence the Design of International Space Station Propulsion Module

The overall design for the International Space Station (ISS) Propulsion (Prop) Module consists of two bell shapes connected by a long tube having a shirt sleeve environment. The tube is to be used by the flight crew to transfer equipment and supplies from the Shuttle to ISS. Due to a desire to use existing space qualified hardware, the tube internal diameter was initially set at 38 inches, while the human engineering specification, NASA-STD-3000, required 50". Human computer modeling using the MannequinPro application was used to help make the case to enlarge the passageway to meet the specification. 3D CAD models of Prop Module were created with 38 inches, 45 inches and 50 inches passageways and human figures in the neutral body posture as well as a fetal posture were inserted into the model and systematically exercised. Results showed that only the 50 inches tube would accommodate a mid tube turn around by a large crew member, 95th percentile American males, by stature.

Hamilton, George S.↗

Space station propulsion options

The selection of the propulsion system for the Space Station represents a complex issue. The present paper provides a summary of the Station design factors which dictate the propulsion requirements, taking into account approaches for meeting these requirements. Factors which affect propulsion system selection are related to thrusting strategy, volume and mass limitations, safety and contamination, electrical power, time phasing, synergistic opportunities, propellant scavenging, water electrolysis, and free-flyers. In a discussion of propulsion systems, attention is given to monopropellant options, bipropellant options, and resistojets.

Wilkinson, C. L.↗

Space Shuttle Propulsion

This video gives an overview of the Space Shuttle's propulsion system, giving details on the individual components, their specifications, and functions. Successful launches are shown.

Source record↗

Space Station propulsion system test bed

The test bed to study H2/O2 propulsion technology for the Space Station is discussed. The test bed consists of propellant accumulators, valving, instrumentation, and controls configured in a 9-ft cube. A water electrolysis module was added to simulate the baseline propulsion system configuration. The activation of the test bed is described, and results are presented from tests of the system, including verification of the control system, thruster tests, electrolysis system testing, and acceptance test, oxidizer system, and fuel system blowdowns.

Norman, A. M.↗

Computational fluid dynamics at the Lewis Research Center: An overview

Lewis is a multidisciplinary Center with strong research and development programs in aeronautical and space propulsion, power, space communications, space experiments and materials. Computational fluid dynamics (CFD) is playing an important and growing role in most of these areas. Described here is how CFD is integrated into these programs and highlights elements of the CFD activities. Examples are presented of codes developed to predict flow fields in advanced propulsion systems and several of the code validation experiments are described. The CFD effort at Lewis ranges from basic research on new and improved algorithms through code development to the application of these codes to specific engineering problems. Because of the substantial improvement in CFD's predictive capability, its use at Lewis is on a steep growth path, spreading rapidly into new areas which had not traditionally taken advantage of the techniques of numerical simulation. Multidisciplinary codes and the future direction of CFD at Lewis are discussed.

Stubbs, Robert M.↗

A cermet fuel reactor for nuclear thermal propulsion

Work on the cermet fuel reactor done in the 1960's by General Electric (GE) and the Argonne National Laboratory (ANL) that had as its goal the development of systems that could be used for nuclear rocket propulsion as well as closed cycle propulsion system designs for ship propulsion, space nuclear propulsion, and other propulsion systems is reviewed. It is concluded that the work done in the 1960's has demonstrated that we can have excellent thermal and mechanical performance with cermet fuel. Thousands of hours of testing were performed on the cermet fuel at both GE and AGL, including very rapid transients and some radiation performance history. We conclude that there are no feasibility issues with cermet fuel. What is needed is reactivation of existing technology and qualification testing of a specific fuel form. We believe this can be done with a minimum development risk.

Kruger, Gordon↗

NASA/DOD Flight Experiments Technical Interchange Meeting Proceedings

This document contains the proceedings of the Flight Experiments Technical Interchange Meeting held in Monterey California, October 5-9, 1992. Technical sessions 4 through 8 addressing space structures, propulsion, space power systems, space environments and effects, and space operations are covered. Many of the papers are presented in outline and viewgraph form.

Source record↗

A Plasma Rocket Demonstration on the International Space Station

The Advanced Space Propulsion Laboratory at the NASA Johnson Space Center has been engaged in the development of a magneto-plasma rocket for several years. This type of rocket could be used in the future to propel interplanetary spacecraft. One feature of this concept is the ability to vary its specific impulse so that it can be operated in a mode that maximizes propellant efficiency or a mode that maximizes thrust. For this reason the system is called the Variable Specific Impulse Magneto-plasma Rocket or VASIMR. This ability to vary specific impulse and thrust will allow for optimum low thrust interplanetary trajectories and results in shorter trip times than is possible with fixed specific impulse systems while preserving adequate payload margins. In the development of the VASIMR technology, a series of ground-based experiments and space demonstrations are envisioned. A ground-based experiment of a low-power VASIMR prototype rocket is currently underway at the Advanced Space Propulsion Laboratory. The next step is a proposal to build and fly a 25-kilowatt VASIMR rocket as an external payload on the International Space Station. This experiment will provide an opportunity to demonstrate the performance of the rocket in space and measure the induced environment. The experiment will also utilize the space station for its intended purpose as a laboratory with vacuum conditions that cannot be matched by any laboratory on Earth. The VASIMR experiment will also blaze the trail for the wider application of advanced electric propulsion on the space station. An electric propulsion system like VASIMR, if provided with sufficient electrical power, could provide continuous drag force compensation for the space station. Drag compensation would eliminate the need for reboosting the station, an operation that will consume about 60 metric tons of propellant in a ten-year period. In contrast, an electric propulsion system would require very little propellant. In fact, a system like VASIMR can use waste hydrogen from the station's life support system as its propellant. This waste hydrogen is otherwise dumped overboard. Continuous drag compensation would also improve the microgravity conditions on the station. So electric propulsion can reduce propellant delivery requirements and thereby increase available payload capacity and at the same time improve the conditions for scientific research.

Petro, Andrew J.↗

Space shuttle propulsion estimation development verification

The application of extended Kalman filtering to estimating the Space Shuttle Propulsion performance, i.e., specific impulse, from flight data in a post-flight processing computer program is detailed. The flight data used include inertial platform acceleration, SRB head pressure, SSME chamber pressure and flow rates, and ground based radar tracking data. The key feature in this application is the model used for the SRB's, which is a nominal or reference quasi-static internal ballistics model normalized to the propellant burn depth. Dynamic states of mass overboard and propellant burn depth are included in the filter model to account for real-time deviations from the reference model used. Aerodynamic, plume, wind and main engine uncertainties are also included for an integrated system model. Assuming uncertainty within the propulsion system model and attempts to estimate its deviations represent a new application of parameter estimation for rocket powered vehicles. Illustrations from the results of applying this estimation approach to several missions show good quality propulsion estimates.

Rogers, Robert M.↗