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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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NASA NTRS1973

The cylindrical electrostatic probes for Atmosphere Explorer -C, -D, and -E.

This paper briefly describes the cylindrical electrostatic probes to be used on the new Atmosphere Explorer-C, -D, and -E, and outlines the methods to be employed to analyze the experimental data in terms of electron temperature and ion and electron concentration. Two independent cylindrical sensors and partially redundant electronic systems permit greater reliability in measurements. Measurements are made at 1-sec and 2-sec intervals along the orbit. The sensors themselves have been modified from previous applications to cope with the lower electron temperature expected in these low-altitude orbits and to counter possible surface contamination caused by the hydrazine engines used for orbit adjustments.

Brace, L. H.↗

NASA NTRS1973

Thermal control and structures approach for fluorinated propulsion.

FLOX and fluorine oxidizers require cryogenic storage at 86 K (-305 F) aboard a spacecraft, whereas their respective fuels MMH and hydrazine require room temperature storage. Propulsion configuration trade-off studies have been made for two potential classes of missions, an outer planet orbiter utilizing RTG's and an inner planet orbiter utilizing solar panels. The preliminary designs incorporate the fuel tank within the thermally controlled electronics compartment and expose the cryogenic tank to space. The cryogenic tank is isolated with foam, shadow shields and a titanium truss support. Its vernier temperature control is accomplished with electrical heaters.

Stimpson, L. D.↗

NASA NTRS1973

H2-O2 auxiliary power unit for Space Shuttle vehicles - A progress report.

Description of a program to establish technology readiness of hydrogen-oxygen (H2-O2) auxiliary power units for use on board the Space Shuttle orbiter vehicle. Fundamental objectives include experimentally establishing an acceptable propellant flow control method, verification of combustor stability, and adequate thermal management. An initial auxiliary power unit (APU) configuration with recycled hydrogen flow has been studied and revised toward greater simplicity and scaling ease. The selected APU is a recuperated open-cycle, turbine-driven unit. Series flow of cryogenic hydrogen removes internally-generated heat and heat from the hydraulic system. The revised configuration schematic and its calculated performance are reviewed. A weight comparison is made between the shuttle baseline hydrazine and H2-O2 APU systems, showing that hydrogen-oxygen APUs have the potential of increasing the payload of the Space Shuttle.

Joyce, J. P.↗

NASA NTRS1974

Design criteria monograph for liquid propellant gas generators

Monograph reviews and assesses current design practices, and from them establishes firm guidance for achieving greater consistency in design, increased reliability in end product, and greater efficiency in design effort. Main emphasis of monograph is on bipropellant gas generators using hydrogen peroxide and hydrazine monopropellants.

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NASA NTRS1974

Design of H2-O2 space shuttle APU. Volume 1: APU design

The H2-O2 space shuttle auxiliary power unit (APU) program is a NASA-Lewis effort aimed at hardware demonstration of the technology required for potential use on the space shuttle. It has been shown that a hydrogen-oxygen power unit (APU) system is an attractive alternate to the space shuttle baseline hydrazine APU system for minimum weight. It has the capability for meeting many of the heat sink requirements for the space shuttle vehicle, thereby reducing the amount of expendable evaporants required for cooling in the baseline APU. Volume 1 of this report covers preliminary design and analysis of the current reference system and detail design of the test version of this reference system. Combustor test results are also included. Volume 2 contains the results of the analysis of an initial version of the reference system and the computer printouts of system performance. The APU consists of subsystems for propellant feed and conditioning, turbopower, and control. Propellant feed and conditioning contains all heat exchangers, valves, and the combustor. The turbopower subsystem contains a two-stage partial-admission pressure-modulated, 400-hp, 63,000-rpm turbine, a 0-to 4-g lubrication system, and a gearbox with output pads for two hydraulic pumps and an alternator (alternator not included on test unit). The electronic control functions include regulation of speed and system temperatures; and start-and-stop sequences, overspeed (rpm) and temperature limits, failsafe provisions, and automatic shutdown provisions.

Harris, E.↗

NASA NTRS1974

Burning rate response of liquid monopropellants to imposed pressure oscillations

The combustion characteristics of hydrazine strands were studied under both steady state and oscillatory conditions. A steady strand burner was used to measure steady strand burning rates, liquid temperature distributions and surface temperatures as a function of pressure in the pressure range of 0.32 to 42 atm. It was found that for subatmospheric pressures the burning rate varied as the square root of pressure; for pressures greater than atmospheric the burning rate varied linearly with pressure. A theoretical model of the strand combustion system was developed and matched to the steady burning rates by assuming a reaction order of one for subatmospheric pressures and a reaction order of two for pressures greater than atmospheric. The model was also found to be in good agreement with measurements of liquid temperature distributions and surface temperatures. The results show an increse in the response of the combustion process as interaction occurs with transient liquid phase effects, yielding a band of frequencies where the combustion process exerts sufficient amplifying power to provide a mechanism for driving combustion instability.

Allison, C. B.↗

NASA NTRS1973

Analytical and experimental study of resonance ignition tubes

The application of the gas-dynamic resonance concept was investigated in relation to ignition of rocket propulsion systems. Analytical studies were conducted to delineate the potential uses of resonance ignition in oxygen/hydrogen bipropellant and hydrazine monopropellant rocket engines. Experimental studies were made to: (1) optimize the resonance igniter configuration, and (2) evaluate the ignition characteristics when operating with low temperature oxygen and hydrogen at the inlet to the igniter.

Stabinsky, L.↗

NASA NTRS1973

System design of the Pioneer Venus spacecraft. Volume 10: Propulsion/orbit insertion subsystem studies

The Pioneer Venus orbiter and multiprobe missions require spacecraft maneuvers for successful accomplishment. This report presents the results of studies performed to define the propulsion subsystems required to perform those maneuvers. Primary goals were to define low mass subsystems capable of performing the required missions with a high degree of reliability for low cost. A review was performed of all applicable propellants and thruster types, as well as propellant management techniques. Based on this review, a liquid monopropellant hydrazine propulsion subsystem was selected for all multiprobe mission maneuvers, and for all orbiter mission maneuvers except orbit insertion. A pressure blowdown operating mode was selected using helium as the pressurizing gas. The forces associated with spacecraft rotations were used to control the liquid-gas interface and resulting propellant orientation within the tank.

Rosenstein, B. J.↗

NASA NTRS1974

The hard start phenomena in hypergolic engines. Volume 1: Bibliography

A bibliography of reports pertaining to the hard start phenomenon in attitude control rocket engines on Apollo spacecraft is presented. Some of the subjects discussed are; (1) combustion of hydrazine, (2) one dimensional theory of liquid fuel rocket combustion, (3) preignition phenomena in small pulsed rocket engines, (4) experimental and theoretical investigation of the fluid dynamics of rocket combustion, and (5) nonequilibrium combustion and nozzle flow in propellant performance.

Miron, Y.↗

NASA NTRS1974

The hard start phenomena in hypergolic engines. Volume 2: Combustion characteristics of propellants and propellant combinations

The combustion characteristics of hypergolic propellants are described. A research project was conducted to determine if the reaction control system engine propellants on Apollo spacecraft undergo explosive reaction when subjected to conditions present in the engine at the time of ignition. Combustion characteristics pertinent to the hard-start phenomenon are considered. The thermal stability of frozen mixtures of hydrazine-based fuels with nitrogen tetroxide was analyzed. Results of the tests are presented in the form of tables and graphs.

Miron, Y.↗

NASA NTRS1974

Reusable Agena study. Volume 1: Executive summary

The shuttle Agena upper stage interim tug concept is based on a building block approach. These building block concepts are extensions of existing ascent Agena configurations. Several current improvements, have been used in developing the shuttle/Agena upper stage concepts. High-density acid is used as the Agena upper stage oxidizer. The baffled injector is used in the main engine. The DF-224 is a fourth generation computer currently in development and will be flight proven in the near future. The Agena upper stage building block concept uses the current Agena as a baseline, adds an 8.5-inch (21.6 cm) extension to the fuel tank for optimum mixture ratio, uses monomethyl hydrazine as fuel, exchanges a 150:1 nozzle extension for the existing 45:1, exchanges an Autonetics DF-224 for the existing Honeywell computer, and adds a star sensor for guidance update. These modifications to the current Agena provide a 5-foot (1.52m) diameter shuttle/Agena upper stage that will fly all Vandenberg Air Force Base missions in the reusable mode without resorting to a kick motor. The delta V velocity of the Agena is increased by use of a strap-on propellant tank option. This option provides a shuttle/Agena upper stage with the capability to place almost 3900 pounds (1769 kg) into geosynchronous orbit (24 hour period) without the aid of kick motors.

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NASA NTRS1974

The development of a non-cryogenic nitrogen/oxygen supply system

A hydrazine/water electrolysis process system module design was fabricated and tested to demonstrate component and module performance. This module is capable of providing both the metabolic oxygen for crew needs and the oxygen and nitrogen for spacecraft leak makeup. The component designs evolved through previous R and D efforts, and were fabricated and tested individually and then were assembled into a complete module which was successfully tested for 1000 hours to demonstrate integration of the individual components. A survey was made of hydrazine sensor technology and a cell math model was derived.

Greenough, B. M.↗

NASA NTRS1974

SS/RCS surface tension propellant acquisition/expulsion tankage technology program

An evaluation of published propellant physical property data together with bubble point tests of fine-mesh screen in propellants, was conducted. The effort consisted of: (1) the collection and evaluation of pertinent physical property data for hydrazine (N2H4), monomethylhydrazine (MMH), and nitrogen tetroxide (N2O4); (2) testing to determine the effect of dissolved pressurant gas, temperature, purity, and system cleanliness or contamination on system bubble point, and (3) the compilation and publishing of both the literature and test results. The space shuttle reaction control system (SS/RCS) is a bipropellant system using N2O4 and MMH, while the auxiliary power system (SS/APU) employs monopropellant N2H4. Since both the RCS and the APU use a surface tension device for propellant acquisition, the propellant properties of interest are those which impact the design and operation of surface tension systems. Information on propellant density, viscosity, surface tension, and contact angle was collected, compiled, and evaluated.

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NASA NTRS1973

Electric propulsion status and development plans - NASA programs

The current status of the NASA auxiliary and primary electric propulsion programs is reviewed. Plans for continuation of these programs and future target goals are also outlined. In auxiliary propulsion, progress on the ion engine flight experiment for the Application Technology Satellite (ATS)-F launch in 1974 to demonstrate North-South station keeping capability is reviewed. In addition, work on small pulsed plasma thrusters and hydrazine resistojets for attitude control applications are also described. In primary propulsion, the effort aimed at demonstrating the technology for solar electric propulsion is presented.

Lazar, J.↗

NASA NTRS1973

Current technology in ion and electrothermal propulsion

The state of the art and projected developmental trends in the fields of ion and electrothermal propulsion systems intended for use in long and complex earth-orbital missions and interplanetary spacecraft missions are reviewed. The characteristics of existing thrust vectoring systems are outlined, together with data on the 5-cm and 8-cm electron bombardment thrusters, the cesium bombardment ion thruster, and the 8-cm, 15-cm, and 30-cm thruster using xenon propellant. The electrothermal ammonia system and the electrothermal hydrazine system are described, and the principles of propulsion system selection are examined.

Finke, R. C.↗

NASA NTRS1973

Development and in-flight performance of the Mariner 9 spacecraft propulsion system

On November 14, 1971, Mariner 9 was decelerated into orbit about Mars by a 1334 N (300 lbf) liquid bipropellant propulsion system. This paper describes and summarizes the development and in-flight performance of this pressure-fed, nitrogen tetroxide/monomethyl hydrazine bipropellant system. The design of all Mariner propulsion subsystems has been predicted upon the premise that simplicity of approach, coupled with thorough qualification and margin-limits testing, is the key to cost-effective reliability. The qualification test program and analytical modeling are also discussed. Since the propulsion subsystem is modular in nature, it was completely checked, serviced, and tested independent of the spacecraft. Proper prediction of in-flight performance required the development of three significant modeling tools to predict and account for nitrogen saturation of the propellant during the six-month coast period and to predict and statistically analyze in-flight data.

Evans, D. D.↗

NASA NTRS1975

High-power CW laser using hydrogen-fluorine reaction

Continuous-wave laser has been proposed based on reaction of hydrogen and fluorine. Hydrogen is produced by dissociation of hydrazine, which can be stored as liquid in light containers at room temperature.

Moynihan, P. I.↗

NASA NTRS1974

A feasibility study of developing toroidal tanks for a spinning spacecraft. Part 2: Evaluation of fluid behavior in spinning toroidal tanks

An experimental program was conducted for the purpose of evaluating propellant behavior characteristics in spinning toroidal tanks. The effects of typical mission requirements, and related phenomena upon propellant slosh and settling, and orientation and stability of the ullage were investigated in a subscale model tank under both one-g and low-g acceleration environments. Specific conditions included were axial acceleration, spin rate, spinrate change, and spacecraft wobble, both singly and in combination. Methanol and water in combination with appropriate spin-rates and accelerations of the scale model system were used to simulate the behavior of fluorine, nitrogen tetroxide, monomethylhydrazine, and hydrazine. The experimental results indicate that no major fluid behavior problems would be encountered with the use of toroidal tanks containing any of the four propellants in a proposed spin-stabilized orbiter spacecraft.

Anderson, J. E.↗