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Showing papers on "Rocket published in 1988"


Journal ArticleDOI
TL;DR: A series of 18 pulsed motor tests was conducted in heavy-wall solid rocket motors having an internal case diameter of 8.38 cm as mentioned in this paper, and all of the motors were linearly stable and all were pulsed into nonlinear instability.
Abstract: A series of 18 pulsed motor tests was conducted in heavy-wall solid rocket motors having an internal case diameter of 8.38 cm. The motor length was varied from 0.61 -1.22 m. Three related reduced-smoke propellants and four different grain designs were tested. All of the motors were linearly stable and all were pulsed into nonlinear instability. The data from this test series were used to evaluate the validity of previously developed pulser models and to evaluate the ability of a previously developed nonlinear instability analysis to predict the observed trends in the data. In most cases, the combined pulser and chamber stability models were found to be capable of predicting measured pulse amplitudes to within 10%. The ejecta pulser model had to be modified to account for the effect of internal wave reflection when propellant grain extended up to the nozzle entrance plane. The nonlinear instability analysis demonstrated the ability to predict many of the observed wave amplitude and shift trends in the data as a function of propellant and grain design. This combined analytical/experimental investigation also provides additional insight into the nature of nonlinear pulse triggered instability and the factors that influence its occurrence and severity.

97 citations


Patent
24 Mar 1988
TL;DR: In this paper, a rapid burning propellant charge for applications including igniters, launch eject motors, and gas generators for automobile air gags is proposed. But the charge is not suitable for high-speed combustion.
Abstract: A rapid burning propellant charge for applications including igniters, launch eject motors, and gas generators for automobile air gags. The propellant charge comprises a reticulated substrate having a quantity of interconnected ligaments and a coating of solid propellant material on the ligaments. In order to provide a large amount of surface area for a fast burn time, interstices are between coated ligaments to define propellant surface area for combustion. In applications where minimum smoke is desired, the reticulated substrate is preferably composed of carbon, graphite, or a non-combustible material, and the solid propellant material is preferably a minimum smoke type.

75 citations


Journal ArticleDOI
TL;DR: The tethered mother-daughter rocket experiment (Charge 2) was carried out by a NASA sounding rocket, Black Brant 9, at White Sands Missile Range in New Mexico in December 1985 as discussed by the authors.
Abstract: The tethered mother-daughter rocket experiment (Charge 2) was carried out by a NASA sounding rocket, Black Brant 9, at White Sands Missile Range in New Mexico in December 1985. It was intended to perform a new type of active experiment in space by applying a high voltage between the two payloads, as well as by injecting an electron beam from the tethered rocket system. An insulated conductive wire connecting the two payloads was deployed up to its maximum length of 426 m during the flight. An electron beam from 0.5 to 48 mA at 1 keV was injected from the mother payload. A voltage up to 500 V was applied between the two payloads with and without the beam injection. This paper describes the initial results on the electrodynamic effects induced by the potential difference between the two payloads. Measurements of the v×B electromotive force and the voltage/current characteristics up to 500 V have been explained by a model in which the ion current to the negatively biased payload effectively limited the tether current. Two kinds of VLF waves were observed when the bias voltage was applied between the two payloads; narrow-band emission at 2–4 kHz and broadband emission up to 15 kHz, depending on the applied voltage. The characteristic features of these emissions suggest that the lower hybrid instability (modified two-stream instability) driven by the potential difference between the rocket and the ambient plasma was responsible for the wave generation.

35 citations


Proceedings ArticleDOI
15 Jun 1988
TL;DR: In this paper, the problem of on-board trajectory optimization for an airbreathing, single-stage-to-orbit vehicle is examined, and a simple model representative of the aerospace plane concept, including a dual-mode propulsion system composed of SCRAMJET and rocket engines is presented.
Abstract: The problem of on-board trajectory optimization for an airbreathing, single-stage-to-orbit vehicle is examined. A simple model representative of the aerospace plane concept, including a dual-mode propulsion system composed of SCRAMJET and rocket engines, is presented. Consideration is restricted to hypersonic flight within the atmosphere. An energy state approximation is employed in a four-state model for flight of a point mass in a vertical plane. Trajectory constraints, including those of dynamic pressure and aerodynamic heating, are initially ignored. Singular perturbation methods are applied in solving the optimal control problem of minimum fuel climb. The resulting reduced solution for the energy state dynamics provides an optimal altitude profil1e dependent on energy level and control for rocket thrust. A boundary-layer analysis produces an approximate lift control solution in feedback form and accounts for altitude and flight path angle dynamics. The reduced solution optimal climb path is presented for the unconstrained case and the case for which a maximum dynamic pressure constraint is enforced.

33 citations


01 Jan 1988
TL;DR: The data obtained in the most recent Japan-US tether rocket experiment CHARGE 2 have been further analyzed in this paper, where the interaction of the moving tether system across the geomagnetic field with the ionospheric plasma can be explained by a simple model of the current through a plasma.
Abstract: The data obtained in the most recent Japan-US tether rocket experiment CHARGE 2 have been further analyzed. The interaction of the moving tether system across the geomagnetic field with the ionospheric plasma can be explained by a simple model of the current through a plasma. The response of the tether system when a high voltage is applied is studied and 500 volts could be applied without any appreciable discharge. The detected signal of the wave excited by an application of high voltage between the mother and daughter rocket and by a pulse modulated electron beam is also studied.

27 citations


Journal ArticleDOI
TL;DR: In this paper, an experimental investigation of hybrid rocket engines (HRE) is performed to study the throttling performance within a thrust range of 10:1, where secondary gas injection (gasification) was used.
Abstract: An experimental investigation of hybrid rocket engines (HRE) is performed to study the throttling performance within a thrust range of 10:1. In order to improve the throttling properties over the entire thrust range, the method of secondary gas injection (gasification) was used. The injection gases were reactive (O2) and inert (N2). High-pressure tests were carried out up to 70 bar to increase the burning rate and the specific impulse. The standard fuel in this study was a composition of aromatic and cyclic amine with red fuming nitric acid (RFNA) as the oxidizer. Controllable, stable, and reproducible throttling properties were demonstrated down to 10% of thrust. The performance with gasification demonstrated the general feasibility of wide-range throttling with fixed-injection geometry. The paper outlines a method for calculating the ballistic behavior of hybrid propellant combinations that is based upon the regression characteristic and the effects of gasification. a A c* F G =m/A m O/F = mn/m PC

23 citations


01 Apr 1988
TL;DR: In this article, the authors present the results of a study of five combined cycle propulsion systems capable of accelerating a single stage vehicle with lifting surfaces from ground launch to Earth orbit, including air-breathing, rocket-based combined cycle (RBCC) engines.
Abstract: : This report presents the results of a study of five combined cycle propulsion systems capable of accelerating a single stage vehicle with lifting surfaces from ground launch to Earth orbit. The engines studied were airbreathing, rocket based combined cycle (RBCC) engines. 'Combined Cycle' engines integrate airbreathing and rocket propulsion systems into a single engine system. These engines transition from initial air-augmented rocket mode takeoff and initial acceleration to ramjet to scramjet and finally to rocket propulsion to orbital insertion velocity. Engine systems, engine/vehicle integration, vehicle structure, propellant storage systems and thermal protection system (TPS) design, sizing and weight estimation, overall performance on various trajectories, and ground support systems were studied. A technology assessment, subscale engine test plan, development program plan and life cycle costs estimates are presented. Keywords: Air augmented rockets, Ramjets, Scramjets, Orbit on demand, Combined cycle engines, Space vehicles.

18 citations


Journal ArticleDOI
TL;DR: In this paper, the effect of solids loading on the ballistic and mechanical properties of polybutadiene composite polymers was investigated and the authors reported the results of the effects of the solids load on the composite properties.

17 citations


Journal ArticleDOI
TL;DR: In this paper, a two-parameter family of singular arcs was generated for time-range fuel problems of an ascending rocket, using the modeling of Zlatskiy and Kiforenko.
Abstract: Presently studied is the problem of the ascent and acceleration of a vehicle in atmospheric flight in which a variable-thrust arc forms a part of the optimal trajectory. A two-parameter family of singular arcs was generated for time-range-fuel problems of an ascending rocket, using the modeling of Zlatskiy and Kiforenko. The shortterm optimality of singular subarcs has been checked in terms of certain necessary conditions: the classical Clebsch condition, the Kelley condition or the Generalized Legendre-Clebsch condition, and the Goh condition. All of these are found to be satisfied computationally for all the candidates. The calculations were repeated for simplified thrust-along-the path modeling and similar results on optimality were obtained.

15 citations


Patent
24 Mar 1988
TL;DR: In this article, the authors propose a method for operating a rocket engine by injecting fuel and oxidizer into an elongated combustion chamber in two flows, a core flow where the oxidizer and fuel are intimately mixed and immediately combusted and a peripheral curtain flow which surrounds the core flow and which is in contact with the combustion chamber wall to cool it and limit the heat transfer from the wall to the injector to prevent vapor locks in an injector.
Abstract: A method for operating a rocket engine by injecting fuel and oxidizer into an elongated combustion chamber in two flows, a core flow where the fuel and oxidizer are intimately mixed and immediately combusted and a peripheral curtain flow which surrounds the core flow and which is in contact with the combustion chamber wall to cool it and limit the heat transfer from the wall to the injector to prevent vapor locks in the injector. To prevent decomposed or partially combusted propellant products from chemically reacting with the chamber wall no mixing of fuel and oxidizer takes place in the curtain flow. The curtain flow is deflected radially inward into the core flow, before decomposed or partially combusted products can come into contact with the wall, into the core flow to fully combust the curtain flow out of contact with the wall. The rocket engine is defined by serially arranged first and second combustion chambers and an injector constructed to form the core and curtain flows. A ring plate projects radially inward at the downstream end of the first chamber and deflects the curtain flow into the coreflow.

15 citations


Proceedings ArticleDOI
16 Aug 1988
TL;DR: In this article, the basic chemical physics which govern both the emitted and scattered ultraviolet rocket plume signatures for selected rocket types in both low and high altitude regimes are reviewed, along with important solar fluorescence and Mie scattering processes.
Abstract: Space and aircraft based sensors working in the ultraviolet spectral region may offer many advantages over longer wavelength systems designed to monitor, identify and track rockets. However, the ultraviolet signatures of various rockets are known to display great sensitivity to operational parameters such as propellant type, oxidizer/fuel ratio, and combustor and nozzle design, as well as trajectory parameters including altitude and degree of solar illumination. This paper will review the basic chemical physics which govern both the emitted and scattered ultraviolet rocket plume signatures for selected rocket types in both low and high altitude regimes. Key chemiluminescent and thermal emission processes will be discussed along with important solar fluorescence and Mie scattering processes. Important emitting and scattering species in the near ultraviolet (400-300 nm), mid ultraviolet (300-200 nm) and far ultraviolet (200-100 nm) spectral regions will be identified and their impact on both spectral signatures and spatial images will be discussed. The ultraviolet absorption properties of the atmosphere and their effects on the utility of the various ultraviolet spectral regions for aircraft and satellite borne sensors will also be presented. Major areas which require further laboratory or theoretical research will be identified.


01 Dec 1988
TL;DR: In this article, an investigation into the behavior of aluminized solid propellant combustion in a two-dimensional windowed rocket motor was conducted using holographic techniques, where holograms were recorded in the motor port, aft of the propellant grain and at the entrance to the exhaust nozzle for two different propellant compositions at varying operating pressures.
Abstract: : An investigation into the behavior of aluminized solid propellant combustion in a two-dimensional windowed rocket motor was conducted using holographic techniques. Holograms were recorded in the motor port, aft of the propellant grain and at the entrance to the exhaust nozzle for two different propellant compositions at varying operating pressures. Quantitative particle size data for particles larger than 20 microns were obtained from the holograms. From these data, the mean diameters (D32) of the larger particles were calculated and utilized to compare what effects pressure, location in the motor and aluminum content had on the behavior of the aluminum/aluminum oxide particles. D32 was found to decrease with increasing pressure, but was unaffected by variations in low values of propellant aluminum loading. D32 at the grain exit was found to be significantly less than within the grain port. Keywords: Solid propellant rocket engines, Solid rocket propellants, Theses.

Journal ArticleDOI
TL;DR: A tethered payload experiment (Charge-2) was carried out as an international program between Japan and the USA using a NASA sounding rocket at White Sands Missile Range as discussed by the authors, which performed a new type of active experiment in space by injecting an electron beam from a mother-daughter rocket system connected with a long tether wire.

Patent
06 May 1988
TL;DR: Additive mixtures which consist of a) organic compounds with highly conjugated pi-bond systems and longwave main absorption bands in the wavelength range from about 350 to 1200 nm, b) organic surface-active substances and c) organic solvents and suspending agents for the components a and b, are used as agents for increasing the vaporization rates and combustion rates and also the combustion stabilities of liquid propellants or fuels and oxidisers for rocket engines or other high-performance combustion installations which are likewise operated with liquid fuels and in which there are combustion problems comparable to those
Abstract: Additive mixtures which consist of a) organic compounds with highly conjugated pi -bond systems and longwave main absorption bands in the wavelength range from about 350 to 1200 nm, b) organic surface-active substances and c) organic solvents and suspending agents for the components a and b, are used as agents for increasing the vaporisation rates and combustion rates and also the combustion stabilities of liquid propellants or fuels and oxidisers for rocket engines or other high-performance combustion installations which are likewise operated with liquid fuels and in which there are combustion problems comparable to those in rocket engines and caused by disturbances in energy transfer. The additive mixtures are injected into the combustion chamber together with the propellants or fuels and the oxidisers with uniform distribution, which is as symmetrical as possible, in a geometrically optimum manner in accordance with defined economical methods. Owing to their property of exchanging radiation energy, highly conjugated pi -bond systems effect in combination with surface-active substances faster, more uniform activations of major fractions of molecules participating in the combustion up to the stage of the state ready for reaction, which is tantamount to enhanced stabilisation of the combustion process.

Proceedings ArticleDOI
01 Jan 1988
TL;DR: In this paper, a comprehensive numerical analysis has been carried out to study the unsteady flowfields in a simulated rocket-motor environment, based on the time-dependent compressible Navier-Stokes equations with a two-equation turbulence closure scheme.
Abstract: A comprehensive numerical analysis has been carried out to study the unsteady flowfields in a simulated rocket-motor environment The model is based on the time-dependent compressible Navier-Stokes equations with a two-equation turbulence closure scheme Various important aspects of the coupling between acoustic oscillations and mean flowfields, including flow reversal, modification of transport properties, etc, are addressed Results indicate that multi-dimensional effects play important roles in determining local flow structures and wave characteristics In much of the domain, acoustic velocity nodal points are observed in the near-wall region The classical one-dimensional theory fails to describe several important mechanisms associated with velocity-induced flow instabilities

Journal ArticleDOI
TL;DR: In this article, a numerical model for the description of ignition transient flow behavior of pellet-dispersion igniter systems is presented, specifically developed for the study of conventional bag and cartridge igniters employed for small-diameter, composite-propellant rocket motors.
Abstract: A fairly comprehensive practical numerical model for the description of ignition transient flow behavior of pellet-dispersion igniter systems is presented. The model was specifically developed for the study of conventional bag and cartridge igniters employed for small-diameter, composite-propellant rocket motors, but the model in its general form may be adapted for the study of a multitude of ignition transient problems. An extensively modified algorithm based on the random-choice method is applied to obtain the solution of the one-dimensional hydrodynamic equations governing the two-phase core flow behavior within the motor chamber and nozzle, in conjunction with pressure-dependent and crossflow-dependent burning rate equations for the solid propellant and igniter pellets. Good agreement is obtained between experimental firing data and predictions from the model for head-end pressure-time profiles.

Proceedings ArticleDOI
11 Jul 1988
TL;DR: In this article, computer models of rocket engines and single-stage-to-orbit vehicles that were developed by the DFVLR and NASA have been combined and the resulting code consists of engine mass, performance, trajectory and vehicle sizing models.
Abstract: Computer models of rocket engines and single-stage-to-orbit vehicles that were developed by the authors at DFVLR and NASA have been combined. The resulting code consists of engine mass, performance, trajectory and vehicle sizing models. The engine mass model includes equations for each subsystem and describes their dependences on various propulsion parameters. The engine performance model consists of multidimensional sets of theoretical propulsion properties and a complete thermodynamic analysis of the engine cycle. The vehicle analyses include an optimized trajectory analysis, mass estimation, and vehicle sizing. A vertical-takeoff, horizontal-landing, single-stage, winged, manned, fully reusable vehicle with a payload capability of 13.6 Mg (30,000 lb) to low earth orbit was selected. Hydrogen, methane, propane, and dual-fuel engines were studied with staged-combustion, gas-generator, dual bell, and the dual-expander cycles. Mixture ratio, chamber pressure, nozzle exit pressure liftoff acceleration, and dual fuel propulsive parameters were optimized.


01 Dec 1988
TL;DR: In this article, the authors search for the optimal launch time of a discontinuous, low thrust transfer between non-coplanar, circular orbits, where the spacecraft is assumed to be solar-powered rocket that cannot provide thrust in the earth's shadow.
Abstract: : This thesis searches for the optimal launch time of a discontinuous, low thrust transfer between non-coplanar, circular orbits The spacecraft is assumed to be solar-powered rocket that cannot provide thrust in the earth's shadow Two time scales are used to calculate a minimum time trajectory The fast timescale produces a control law which maximizes a change in orbital elements for a single orbit The slow timescale incorporates the control law so that the final boundary conditions are met in minimum time Minimum transfer times are determined between winter and summer Keywords: Low thrust; Electric propulsion; Orbit transfer; Solar propulsion; Transfer trajectories (jhd)

Patent
25 Jan 1988
TL;DR: In this paper, a system for the recovery of liquid fuel rocket engines used in space flight is described, which consists of a sphere with a normally circumferential open portion for containing a rocket engine.
Abstract: The disclosure is directed to a system for recovery of liquid fuel rocket engines used in space flight. The system comprises a sphere with a normally circumferential open portion for containing a rocket engine. The sphere is fixedly attached to the space vehicle. The engine is attached to the inner surface of the sphere in a manner allowing normal engine functions including but not limited to gimbaling. The normal engine hookup is provided via disconnects on the outer surface of the sphere. A pair of sphere closure sections are carried on rails within the sphere adjacent to the normally open portion of the sphere. When the use of the engine in space flight is completed generally prior to vehicle orbit, actuation devices translate the closure sections into the normally open portion of the sphere sealing the opening thereby forming an integral closed sphere, the sphere containing the engine is disconnected from the vehicle by explosive bolts or the like and then the sphere falls from the vehicle towards earth. After reaching the earth's atmosphere, a parachute is deployed to slow the falling speed of the sphere. The sphere can be recovered by air or sea recovery and the system can be reused.


Journal ArticleDOI
TL;DR: A review of the nuclear rocket program (Rover/NERVA) that was carried on from the mid-fifties until 1973 leads to the philosophy that flight safety considerations should start with the design process and provide solutions that are built into the design as mentioned in this paper.

Proceedings ArticleDOI
06 Apr 1988
TL;DR: The SPEAR I and SPEAR II sounding rocket flights as mentioned in this paper carried the highest exposed voltage systems yet flown in space and were used to investigate the electrical current drain to highly charged objects in the ionosphere.
Abstract: The SPEAR I and SPEAR II sounding rocket flights, will carry the highest exposed voltage systems yet flown in space. SPEAR I was launched December 13, 1987, to investigate the electrical current drain to highly charged objects in the ionosphere. SPEAR I results, augmented with laboratory and theoretical studies, will be used to determine the ambient conditions that would cause discharging and arcing of high power systems in space. These results will then be used for the design, test and flight of high power systems. SPEAR II, scheduled for launch in early 1989, will involve the innovative operations of high voltage and high current systems in the ionosphere. These flight programs utilize theoretical research efforts of several groups, as well as vacuum and plasma chamber testing of high power systems. Innovative aspects will include the exposure of uninsu-lated transmission and pulse forming systems to the ambient plasma, the charging and use of high energy storage systems during flight, and the use of high voltage and high current loads not previously used in space. Unique problems include outgassing, mitigation of electrical breakdown, loading, and the use of innovative spacecraft integration techniques for commands and telemetry to high voltage systems.

Journal ArticleDOI
TL;DR: In this paper, a simple model relating optimum exhaust velocity and maximum system delta-V as a function of system-specific energy is developed, which provides insight into the relationship between system performance and various power and propulsion subsystem characteristics.
Abstract: Propulsion requirements for launch vehicles, upper stages, satellites and platforms, and planetary spacecraft are described from a functional perspective and compared on an energy basis. Mission velocity requirements for a range of missions are presented. A simple model relating optimum exhaust velocity and maximum system delta-V as a function of system-specific energy is developed, which provides insight into the relationship between system performance and various power and propulsion subsystem characteristics. Based on this model, various advanced propulsion options, e.g., the solid-core nuclear rocket and nuclear electric propulsion, are evaluated, and the implications of this analysis for propulsion and power system technology development programs are discussed. The objective of this paper is to provide an overview of future propulsion requirements for the nonspecialist.

Journal ArticleDOI
TL;DR: The S-310JA-11 and S-10JA-12 rockets, having a vector magnetometer with high sensitivity (1.8nT) and high sampling frequency (100Hz), were launched into the aurora on May 29 and July 12, 1985, from Syowa Station, Antarctica as discussed by the authors.
Abstract: The S-310JA-11 and S-310JA-12 rockets, having a vector magnetometer with high sensitivity (1.8nT) and high sampling frequency (100Hz), were launched into the aurora on May 29 and July 12, 1985, from Syowa Station, Antarctica. The S-310JA-11 rocket penetrated twice quiet arcs, while the S-310JA-12 rocket traversed across intense and active auroral arcs during a large magnetic substorm. In the S-310JA-12 rocket experiment, intense field-aligned currents of 400-600nT were observed when the rocket penetrated an active arc during the descending flight. The magnetometer on board the S-310JA-12 rocket also detected intense electrojet currents with a center at 110km on the upward leg and at 108km on the downward leg. The magnetometer data of the S-310JA-11 rocket showed no distinguished magnetic field variation due to field-aligned current and electrojet.

Journal ArticleDOI
TL;DR: In this paper, results from an iono-ipheric founding rocket of the "mother-daugther" type, equipped with an 8 keV electron accelerator, are reported.

01 Jan 1988
TL;DR: In this article, the design and fabrication of an electroformed RFQ for the BEAR (beam experiments aboard a rocket) project is described, and the design of this l m long, lightweight (
Abstract: Abstract Los Alamos National Laboratory, Grumman, and GAR Electroformers have completed the design and fabrication of an electroformed RFQ for the BEAR (beam experiments aboard a rocket) project. The design of this l m long, lightweight (

Journal ArticleDOI
TL;DR: In this article, the influence of the control system on the CEP with respect to the assumed error budget was investigated for three different cases, namely, no control, attitude control, and control with the aid of a strapdown inertia! platform.
Abstract: Extensive aeromechanical calculations were performed for a ground-to-ground rocket with a range of 120 km. The first objective was to investigate the influence of the control system on the circular error probability (CEP) with respect to the assumed error budget. Results are presented for three different cases, namely: no control, attitude control, and control with the aid of a strapdown inertia! platform. It is demonstrated that only the application of the latter permits compensating for the effect of even large total-impulse deviations. Rocket control is carried out by fin deflections only. Examples are also given that show the influence of static margin and axial-force coefficients on the CEP. The second objective was to find out the maximum total-impulse deviation that could be completely neutralized by means of aerodynamic controls.