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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 1,153 records · Page 64
All sourcesNASA NTRSDOE OSTI
NASA NTRS1976

EDIN design study alternate space shuttle booster replacement concepts. Volume 1: Engineering analysis

The use of a recoverable liquid rocket booster (LRB) system to replace the existing solid rocket booster (SRB) system for the shuttle was studied. Historical weight estimating relationships were developed for the LRB using Saturn technology and modified as required. Mission performance was computed using February 1975 shuttle configuration groundrules to allow reasonable comparison of the existing shuttle with the study designs. The launch trajectory was constrained to pass through both the RTLS/AOA and main engine cut off points of the shuttle reference mission 1. Performance analysis is based on a point design trajectory model which optimizes initial tilt rate and exoatmospheric pitch profile. A gravity turn was employed during the boost phase in place of the shuttle angle of attack profile. Engine throttling add/or shutdown was used to constrain dynamic pressure and/or longitudinal acceleration where necessary. Four basic configurations were investigated: a parallel burn vehicle with an F-1 engine powered LRB; a parallel burn vehicle with a high pressure engine powered LRB; a series burn vehicle with a high pressure engine powered LRB. The relative sizes of the LRB and the ET are optimized to minimize GLOW in most cases.

Demakes, P. T.↗
NASA NTRS2002

Extending Ion Engine Technology to NEXT and Beyond

Extending ion engine technology beyond the current state-of-the art primary interplanetary electric propulsion system, the 2.3-kW NASA Solar Electric Propulsion Technology and Applications Readiness (NSTAR) system, will require thrusters with improved propellant throughput and total impulse capability. Many of the design choices that culminated in the NSTAR thrusters must be revisited, and their application to next generation ion engine technology must be evaluated. The concept of derating, which was successfully employed in NSTAR, has been applied to the 40 cm NASA Evolutionary Xenon Thruster (NEXT) currently under development at NASA Glenn Research Center (GRC). At 5-kW, NEXT operates with the same average beam current density as NSTAR, and at 10-kW, the peak beam current density is only ten percent greater than NSTAR. The result is that similar Ion optics technology is expected to yield comparable lifetime. Thick-accelerator- grid ion optics are also being tested to realize additional lifetime benefits. A 40-A discharge cathode is being developed for NEXT based on scaling the NSTAR design. Nevertheless, the experiences of the NSTAR ground tests and the thruster on the Deep Space One spacecraft indicate that the discharge cathode wear must be studied experimentally and theoretically to ensure that it meets the lifetime requirements. Although NEXT is in its infancy, investigations have already begun to examine possible modifications to engine design for even higher-power and higher-specific impulse engines. Ion optics using alternate materials such as titanium, graphite, or carbon-carbon composite are currently being investigated due to their low sputter yields at high voltage. To avoid the difficulties encountered using electrodes at high-currents, the use of a microwave-based ion thruster is under investigation for potential high-power ion thruster systems requiring long lifetimes. Additionally, alternative propellants are being considered for applications requiring high-specific impulse (>> 5000 s) and extremely long-life (>> 15,000 hr). Testing requirements make condensable propellants attractive for high-power engines. Although the NSTAR ion engine demonstrated the flight maturity of ion thruster technology, many challenges remain for the development of thrusters with improved propellant throughput and power handling capabilities.

Domonkos, Matthew T.↗
NASA NTRS1989

Design of a lunar transportation system

The development of a good transportation infrastructure is a major requirement for the establishment of a permanent lunar base. Transportation is characterized by the technology available in a specific time frame and the need to transport personnel and cargo between Earth and Moon, and between lunar bases. In our study, attention was first focused on developing a transportation system for the first generation lunar base. As a first step, a tracked-type multipurpose lunar transportation vehicle was considered as a possible mode of transportation and a detailed study was conducted on the various aspects of the vehicle. Since the vehicle is composed of many moving parts, exposing it to the environment of the Moon, where fine dust particles are prevalent, can cause problems associated with lubrication and friction. The vehicle also posed problems concerning weight and power. Hence, several modifications were made to the above design ideas conceptually, and a Lunar Articulated Remote Transportation System (Lunar ARTS) is proposed as a more effective alternative with the following objectives: (1) minimizing the transportation of construction material and fuel from Earth or maximizing the use of the lunar material; (2) use of novel materials and light-weight structures; (3) use of new manufacturing methods and technology such as magnetic levitation using superconducting materials; and (4) innovative concepts of effectively utilizing the exotic lunar conditions, i.e., high thermal gradients, lack of atmosphere, lower gravity, etc. To achieve the above objectives of designing transportation systems from concept to operation, the project was planned in three phases: (1) conceptual design; (2) detailed analysis and synthesis; and (3) construction, testing, evaluation, and operation. In this project, both phases 1 and 2 have been carried out and work on phase 3 is in progress. In this paper, the details of the Lunar ARTS are discussed and the future work on the vehicle are also outlined.

Sankaravelu, A.↗
NASA NTRS2018

Sample Return Systems for Extreme Environments (SaRSEE)

Sample return missions offer a greater science yield when compared to missions that only employ in situ experiments or remote sensing observations, since they allow the application of more complex technological and analytical methodologies in controlled terrestrial laboratories,that are both repeatable and can be independently verified. The successful return of extraterrestrial materials over the last four decades has contributed to our understanding of the solar system, but retrieval techniques have largely depended on the use of either soft-landing, or touch-and-go procedures that result in high V requirements, larger spacecraft mass ratios, and return yields typically limited to a few grams of surface materials that have experienced varying degrees of alteration from space weathering. Hard-landing methods using planetary penetrators offer an alternative for sample return that significantly reduce a mission's V and mass ratios,increase sample yields, and allow for the collection of subsurface materials, and lessons can be drawn from previous sample return missions. The following details progress in the design,development, and testing of penetrator/sampler technology capable of surviving subsonic and low, supersonic impact velocities (<700 m/s) that would enable the collection of geologic materials using tether technology to return the sample to a passing spacecraft. The testing of energy absorbing material for protecting the sample, design evolution and field testing of the penetrator, and dynamic modeling of tether behavior during sampling are discussed. It is shown through both modeling and field testing that penetrators at speeds between 300-600 m/s (~Mach 1-2) can penetrator into the ground to depths of 1-2 m with overall structural integrity attained.The first flight tests demonstrated the potential for survivability at these speeds. The second flight series demonstrated core sample collection with partial ejection of the sample return canister. The 3rd flight series demonstrated self-ejection of the sample return system fully intact and with the core retaining the full stratigraphy of the rock bed. The tether analysis shows that the forces on the tether during release and return of the sample to the main spacecraft are all at levels that can easily be handled by existing tether materials. The mass analysis of the requirements indicates that sample return form the asteroids could be handled with Discovery or New Frontier range of missions dependent on the number of samples to be returned to the Earth.

Winglee, R. M.↗
NASA NTRS1983

Replacing critical and strategic refractory metal elements in nickel-base superalloys

Because of the import status and essential nature of their use, cobalt, chromium, tantalum, and niobium were identified as strategic and critical in the aerospace industry. NASA's Conservation of Strategic Aerospace Materials (COSAM) program aims to reduce the need for strategic materials used in gas turbine engines. Technological thrusts in two major areas are under way to meet the primary objective of conserving the use of strategic materials in nickelbase superalloys. These thrusts consist of strategic element substitution and alternative material identification. The program emphasizes cooperative research teams involving NASA Lewis Research Center, universities, and industry. The adoption of refractory metals in nickel-base superalloys is summarized including their roles in mechanical strengthening and environmental resistance; current research activities under way in the COSAM Program are presented as well as research findings to date.

Stephens, J. R.↗
NASA NTRS1985

Thermal management system options for high power space platforms

Thermal Management System (TMS) design options for a high power (75kWe), low earth orbit, multimodule space platform were investigated. The approach taken was to establish a baseline TMS representative of current technology, and to make incremental improvements through successive subsystem trades that lead to a candidate TMS. The TMS trades included centralized and decentralized transport, single-phase and two-phase transport, alternate working fluids, liquid loop and heat pipe radiators, deployed fixed, body mounted and steerable radiators, and thermal storage. The subsystem options were evaluated against criteria such as weight, TMS power requirement, reliability, system isothermality penalty, and growth potential.

Sadunas, J. A.↗
NASA NTRS1985

Microwave electric propulsion for orbit transfer applications

A Microwave Electric Propulsion (MEP) concept is developed for an unmanned Orbit Transfer Vehicle (OTV). The concept is based on the use of beamed microwave power and on an extrapolation of ion thruster technology. Beamed microwave power transmission is discussed in terms of its relationship to spacecraft propulsion. Characteristics of an MEP OTV are determined and performance is evaluated by comparison to a variety of alternative propulsion systems for the completion of a ten-year mission model.

Sercel, J. C.↗
NASA NTRS1987

Space Station alpha joint bearing

Perhaps the most critical structural system aboard the Space Station is the Solar Alpha Rotary Joint which helps align the power generation system with the sun. The joint must provide structural support and controlled rotation to the outboard transverse booms as well as power and data transfer across the joint. The Solar Alpha Rotary Joint is composed of two transition sections and an integral, large diameter bearing. Alpha joint bearing design presents a particularly interesting problem because of its large size and need for high reliability, stiffness, and on orbit maintability. The discrete roller bearing developed is a novel refinement to cam follower technology. It offers thermal compensation and ease of on-orbit maintenance that are not found in conventional rolling element bearings. How the bearing design evolved is summarized. Driving requirements are reviewed, alternative concepts assessed, and the selected design is described.

Everman, Michael R.↗
NASA NTRS1988

Strategy for D/He-3 fusion development

It is concluded that Deuterium/Helium-3 fusion faces a more difficult physics development path but an easier technology development path than does Deuterium/Tritium. Early D/He-3 tests in next generation D/T fusion experiments might provide a valuable D/He-3 proof-of-principle at modest cost. At least one high leverage alternate concept should be vigorously pursued. Space applications of D/He-3 fusion are critically important to large scale development.

Santarius, John F.↗
NASA NTRS1990

Satellite sound broadcasting system study: Mobile considerations

Discussed here is the mobile reception part of a study to investigate a satellite sound broadcast system in the UHF or L bands. Existing propagation and reception measurements are used with proper interpretation to evaluate the signaling, coding, and diversity alternatives suitable for the system. Signal attenuation in streets shadowed by buildings appear to be around 29 db, considerably higher than the 10 db adopted by CCIR. With the marriage of proper technologies, an LMSS class satellite can provide substantial direct satellite audio broadcast capability in UHF or L bands for high quality mobile and portable indoor reception by low cost radio receivers. This scheme requires terrestrial repeaters for satisfactory mobile reception in urban areas. A specialized bandwidth efficient spread spectrum signalling technique is particularly suitable for the terrestrial repeaters.

Golshan, Nasser↗
NASA NTRS2004

High-Power Krypton Hall Thruster Technology Being Developed for Nuclear-Powered Applications

The NASA Glenn Research Center has been performing research and development of moderate specific impulse, xenon-fueled, high-power Hall thrusters for potential solar electric propulsion applications. These applications include Mars missions, reusable tugs for low-Earth-orbit to geosynchronous-Earth-orbit transportation, and missions that require transportation to libration points. This research and development effort resulted in the design and fabrication of the NASA-457M Hall thruster that has been tested at input powers up to 95 kW. During project year 2003, NASA established Project Prometheus to develop technology in the areas of nuclear power and propulsion, which are enabling for deep-space science missions. One of the Project-Prometheus-sponsored Nuclear Propulsion Research tasks is to investigate alternate propellants for high-power Hall thruster electric propulsion. The motivation for alternate propellants includes the disadvantageous cost and availability of xenon propellant for extremely large scale, xenon-fueled propulsion systems and the potential system performance benefits of using alternate propellants. The alternate propellant krypton was investigated because of its low cost relative to xenon. Krypton propellant also has potential performance benefits for deep-space missions because the theoretical specific impulse for a given voltage is 20 percent higher than for xenon because of krypton's lower molecular weight. During project year 2003, the performance of the high-power NASA-457M Hall thruster was measured using krypton as the propellant at power levels ranging from 6.4 to 72.5 kW. The thrust produced ranged from 0.3 to 2.5 N at a discharge specific impulse up to 4500 sec.

Jacobson, David T.↗
NASA NTRS2007

Design Concept for a Nuclear Reactor-Powered Mars Rover

A report presents a design concept for an instrumented robotic vehicle (rover) to be used on a future mission of exploration of the planet Mars. The design incorporates a nuclear fission power system to provide long range, long life, and high power capabilities unachievable through the use of alternative solar or radioisotope power systems. The concept described in the report draws on previous rover designs developed for the 2009 Mars Science laboratory (MSL) mission to minimize the need for new technology developments.

Elliott, John↗
NASA NTRS2010

Recent Stirling Conversion Technology Developments and Operational Measurements at NASA Glenn Research Center

In support of the Advanced Stirling Radioisotope Generator (ASRG) project and other potential applications, NASA Glenn Research Center (GRC) has initiated convertor technology development efforts in the areas of acoustic emission, electromagnetic field mitigation, thermoacoustic Stirling conversion, and multiple-cylinder alpha arrangements of Stirling machines. The acoustic emission measurement effort was developed as a health monitoring metric for several Stirling convertors undergoing life testing. While accelerometers have been used in the past to monitor dynamic signature, the acoustic sensors were chosen to monitor cycle events, such gas bearing operation. Several electromagnetic interference (EMI) experiments were performed on a pair of Advanced Stirling Convertors (ASC). These tests demonstrated that a simple bucking coil was capable of reducing the alternating current (ac) magnetic field below the ASRG system specification. The thermoacoustic Stirling concept eliminates the displacer typically found in Stirling machines by making use of the pressure oscillations of a traveling acoustic wave. A 100 W-class thermoacoustic Stirling prototype manufactured by Northrop Grumman Space and Technology was received and tested. Another thermoacoustic prototype designed and fabricated by Sunpower, Inc., will be tested in the near future. A four cylinder free piston alpha prototype convertor was received from Sunpower, Inc. and has been tested at GRC. This hardware was used as a proof of concept to validate thermodynamic models and demonstrate stable operation of multiple-cylinder free-piston Stirling conversion. This paper will discuss each of these activities and the results they produced.

Oriti, Salvatore M.↗
NASA NTRS2012

Cryogenic Propellant Storage and Transfer Technology Demonstration: Prephase A Government Point-of-Departure Concept Study

The primary purpose of this study was to define a point-of-departure prephase A mission concept for the cryogenic propellant storage and transfer technology demonstration mission to be conducted by the NASA Office of the Chief Technologist (OCT). The mission concept includes identification of the cryogenic propellant management technologies to be demonstrated, definition of a representative mission timeline, and definition of a viable flight system design concept. The resulting mission concept will serve as a point of departure for evaluating alternative mission concepts and synthesizing the results of industry- defined mission concepts developed under the OCT contracted studies

Mulqueen, J. A.↗
NASA NTRS2014

Design and Preliminary Performance Testing of Electronegative Gas Plasma Thruster

In classical gridded electrostatic ion thrusters, positively charged ions are generated from a plasma discharge of noble gas propellant and accelerated to provide thrust. To maintain overall charge balance on the propulsion system, a separate electron source is required to neutralize the ion beam as it exits the thruster. However, if high-electronegativity propellant gases (e.g., sulfur hexafluoride) are instead used, a plasma discharge can result consisting of both positively and negatively charged ions. Extracting such electronegative plasma species for thrust generation (e.g., with time-varying, bipolar ion optics) would eliminate the need for a separate neutralizer cathode subsystem. In addition for thrusters utilizing a RF plasma discharge, further simplification of the ion thruster power system may be possible by also using the RF power supply to bias the ion optics. Recently, the PEGASES (Plasma propulsion with Electronegative gases) thruster prototype successfully demonstrated proof-of-concept operations in alternatively accelerating positively and negatively charged ions from a RF discharge of a mixture of argon and sulfur hexafluoride.i In collaboration with NASA Marshall Space Flight Center (MSFC), the Georgia Institute of Technology High-Power Electric Propulsion Laboratory (HPEPL) is applying the lessons learned from PEGASES design and testing to develop a new thruster prototype. This prototype will incorporate design improvements and undergo gridless operational testing and diagnostics checkout at HPEPL in April 2014. Performance mapping with ion optics will be conducted at NASA MSFC starting in May 2014. The proposed paper discusses the design and preliminary performance testing of this electronegative gas plasma thruster prototype.

Liu, Thomas M.↗
NASA NTRS2015

Miniature Biometric Sensor Project

Heart rate monitoring (HRM) is a critical need during exploration missions. Unlike the four separate systems used on ISS today, the single HRM system should perform as a diagnostic tool, perform well during exercise or high level activity, and be suitable for use during EVA. Currently available HRM technologies are dependent on uninterrupted contact with the skin and are prone to data drop-out and motion artifact when worn in the spacesuit or during exercise. Here, we seek an alternative to the chest strap and electrode based sensors currently in use on ISS today. This project aims to develop a single, high performance, robust biosensor with focused efforts on improved heart rate data quality collection during high intensity activity such as exercise or EVA.

Falker, John↗
NASA NTRS2017

Conceptual Feasibility Study of the Hyperloop Vehicle for Next-Generation Transport

The Hyperloop concept is proposed as a faster, cheaper alternative to high-speed rail and traditional short-haul aircraft. It consists of a passenger pod traveling through a tube under light vacuum while being propelled and levitated by a combination of permanent and electro-magnets. The concept addresses NASA's research thrusts for growth in demand, sustainability, and technology convergence for high-speed transport. Hyperloop is a radical departure from other advanced aviation concepts, however it remains an aeronautics concept that tackles the same strategic goals of low-carbon propulsion and ultra-effcient vehicles. System feasibility was investigated by building a multidisciplinary vehicle sizing model that takes into account aerodynamic, thermodynamic, structures, electromagnetic, weight, and mission analyses. The sizing process emphasized the strong coupling between the two largest systems: the tube and the passenger pod. The model was then exercised to examine Hyperloop from a technical and cost perspective. The structural sizing analysis of the travel tube demonstrates potential for signi cant capital cost reductions by considering an underwater route. Examination of varying passenger capacity indicates that the system can be operated with a wide range of passenger loads without significant change in operating expenses. Lastly, a high-level sizing study simulated variations in tube area, pressure, pod speed, and passenger capacity showing that there is a tube pressure that minimizes operating energy usage. The value of this optimal tube pressure is highly sensitive to numerous design details. These combined estimates of energy consumption, passenger throughput, and mission analyses all support Hyperloop as a faster and cheaper alternative to short-haul flights. The tools and expertise used to quantify these results also demonstrate how traditional aerospace design methods can be leveraged to handle the complex and coupled design process. Much of the technology development required for the Hyperloop is shared with next-generation aircraft. Furthermore, the substantial public interest and active commercial development make it an ideal candidate as an aircraft technology driver and test bed.

Hyperloop Vehicle↗
NASA NTRS1981

Development of Advanced Czochralski Growth Process to produce low cost 150 KG silicon ingots from a single crucible for technology readiness

The modified CG2000 crystal grower construction, installation, and machine check-out was completed. The process development check-out proceeded with several dry runs and one growth run. Several machine calibrations and functional problems were discovered and corrected. Several exhaust gas analysis system alternatives were evaluated and an integrated system approved and ordered. A contract presentation was made at the Project Integration Meeting at JPL, including cost-projections using contract projected throughput and machine parameters. Several growth runs on a development CG200 RC grower show that complete neck, crown, and body automated growth can be achieved with only one operator input. Work continued for melt level, melt temperature, and diameter sensor development.

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