Showing papers on "Rocket published in 1970"

Rocket observation of interstellar molecular hydrogen

Abstract: Interstellar molecular H Lyman resonance-absorption bands in far UV spectrum using rocket observation

Stability of Longitudinal Oscillations with Pressure and Velocity Coupling in a Solid Propellant Rocket

Abstract: Of the various unstable motions observed in solid propellant rocket chambers, the most troublesome currently are those involving oscillatory motions parallel to the axis. Such instabilities are found to arise particularly in larger rockets using propellants which contain aluminum. The problem is formulated here in one-dimensional form and solved for the case of small amplitude standing waves. Both pressure and velocity coupling may be accommodated, although the proper description of the response function for velocity coupling is not yet known. In addition to several special cases, the stability boundary is discussed for a straight chamber having variable cross section. The influences of the mean flow field, the nozzle, particulate matter, and motions of the solid propellant grain are taken into account.

Detection of x-ray emission from 3c 273 and ngc 5128.

Abstract: Extragalactic objects 3C 273 NGC 5128 and M87 X ray emission detection, using proportional counters on Aerobee 150 rocket

Theory of rocket engines

Abstract: : The book treats general questions of the theory and calculation of thermal rocket engines, describes processes of ZhRd and RDTT and considers their characteristics The necessary information about liquid and solid fuels for RD is given In the 2nd considerably reworked edition, contemporary methods of thermogas-dynamic design of processes in RD with high-temperature working media have been more fully explained Results published in recent years of theoretical and experimental investigations to determine thermophysical features of combustion products and characteristics of chemically nonequilibrium processes combustion and expansion are reflected Considerable attention is given to questions of the specific character of two-phase flows and to schemes of heat shielding

General Motion of a Variable-Mass Flexible Rocket with Internal Flow

Abstract: This paper consists of two parts. In the first part a new and general formulation of the dynamical problems associated with the powered flight of variable-mass , flexible rockets with internal gas flow is presented. The formulation comprises six ordinary differential equations for the rigid-body motion and three partial differential equations for the elastic displacements. The equations are nonlinear and possess time-dependent coefficients. The formulation contains as special cases many of the rocket dynamics problems investigated heretofore, and should prove superior when several effects must be considered simultaneously. For a critical examination of the dynamical characteristics of variable-mass bodies, in the second part of the paper an analytical solution of the boundary-value problem with time-dependent coefficients associated with the longitudinal and transverse vibrations of an axially symmetric, variable-mass, spinning rocket is obtained. The paper scrutinizes the concept of normalmode vibration for boost vehicles with rapid mass variation.

Precise Location of Sagittarius X-Ray Sources with a Rocket-Borne Rotating Modulation Collimator

Abstract: X ray sources celestial positions in Sagittarius region, using rocket-borne rotating modulation collimator

Precise Location of Sagittarius X-Ray Sources with a Rocket-Borne Rotating Modulation Collimator

Abstract: X ray sources celestial positions in Sagittarius region, using rocket-borne rotating modulation collimator

Investigations of the T-burner and its role in combustion instability studies

Abstract: Of several devices introduced to study combustion instability in solid rocket propellants, one, known as the "T-burner," has become the most widely used. With this device the response of a burning propellant to a small pressure disturbance can be measured. Such information is vital both to the understanding of unsteady combustion processes as well as to the assessment of the stability characteristics of solid rocket motors. Although the T-burner has been used for several years, several questions concerning the device have arisen and, for the most part, have remained unanswered. Moreover, little effort has been given toward showing the relevance of T-burner data to predictions of instability in rocket motors. The present investigations, comprising over 400 test firings in T-burners of various lengths and diameters, were undertaken with the major objective of gaining a better understanding of the T-burner itself in order to answer some of these unresolved questions. Another objective was to compare T-burner predictions of rocket motor instability with actual observations made in a previous study. Among the investigations was a comparison of several ignition procedures which showed clearly that a poor, uneven ignition can seriously affect the test results. Included among the ignition studies were tests conducted in transparent chambers to permit high-speed motion photography of the firings. These tests confirmed the common assumption that the T-burner is basically a one-dimensional device. Tests using burners of different diameters showed that although the acoustic losses of the T-burner are nearly independent of diameter, the limiting amplitude of the oscillations is strongly dependent on the latter. The dilemma raised by these observations was resolved by measurements which indicate that the heat transfer from the combustion gases to the burner wall is strongly dependent on the amplitude of the waves. From these measurements emerged a nonlinear description of the damping in the T-burner which accounts for both the behavior of the losses as well as that of the limiting amplitude. When two independent T-burner methods were compared, the results obtained were initially in very poor agreement. However, when the T-burner losses were assumed to be non-linear as mentioned earlier, excellent agreement was observed. Finally, the T-burner predictions of instability in rocket motors were in rather poor agreement with direct observations made in a previous study. Although this lack of agreement is not understood, it is doubtful in the light of the present investigations that the major error lies in the T-burner measurements, for these should be relatively accurate. Moreover, these results indicate the need for more comparisons of this type in order to determine the usefulness of the T-burner in predicting combustion instability in solid propellant rockets.

An investigation of combustion instability in hybrid rockets

Abstract: A simple analysis has been developed to describe the transition of hybrid rocket combustion from the diffusion-limited region at high pressure to the kinetic-limited domain at low pressure. Good qualitative agreement has been obtained with measured regression rate behavior in those operating regimes where surface effects such as excessive melting or charring do not occur.

Handbook of model rocketry

Abstract: This Is Model Rocketry. Getting Started. Tools and Techniques in the Workshop. Model Rocket Construction. Model Rocket Motors. Ignition and Ignition Systems. Launchers and Launching Techniques. How High Will It Go?. Stability. Model Rocket Aerodynamics. Multistaged Model Rockets. Recovery Devices. Glide Recovery. Building and Flying Large Models. Payloads. Scale Models. Altitude Determination. Model Rocket Ranges. Clubs and Contests. Epilogue. Bibliography. Appendices. Index.

Range limited projectile system

Abstract: A close range projectile system having a reverse thrust rocket in the projectile which permits maximum projectile velocity and hitting power over short range only.

Positions of X-ray Sources in the Sagittarius Region

Abstract: Celestial positions and intensities of X ray sources in Sagittarius region obtained from rocket experiment

Rocket‐borne measurements of Hβ emissions and energetic hydrogen fluxes during an auroral breakup

Abstract: Intensity and altitude profile of H beta light emission and energetic hydrogen fluxes during auroral breakup using rocket soundings

Fifth and sixth integrals for optimum rocket trajectories in a central field

Abstract: Six integrals of motion are obtained for the fourteenth order problem of minimum fuel rocket trajectories in an inverse square field. These integrals are for both constant exhaust velocity rockets and constant power rockets with unbounded thrust magnitude. The integrals are obtained in two different sets of variables: 1) position and velocity vectors and 2) classical orbit elements. One of the six integrals involves both the payoff and the independent variable, time. The other five integrals involve only the state and adjoint variables. Some applications of the integrals to orbit transfer problems are suggested.

Evaluation of critical mass for open-cycle, gas-core rocket reactors

Abstract: Critical mass calculation for open cycle gas core rocket reactors, considering cavity size, fuel radius, reflector thickness and hydrogen bypass flow

Aircraft rocket firing system

Abstract: A system for firing aircraft rockets including a fluidic generator exposed to the airstream passing the launching aircraft in flight for generating the electrical power necessary to operate the firing circuit. The fluidic generator produces a voltage output when a predetermined minimum air speed is achieved to charge capacitors in the firing circuit. Silicon controlled rectifiers are shunted across the capacitors to immediately discharge them when the aircraft decelerates below the predetermined minimum air speed.

Boundary-layer approximation to powered-flight attitude transients

Abstract: Rocket vehicle flight optimization for model including rigid body degrees of freedom in boundary layer approximation to attitude transients

Electrostatic probe measurements in solid- propellant rocket exhausts

Abstract: A stagnation point electrostatic probe that can be used to measure local electrical characteristics of solid-propell ant rocket exhausts has been developed. The probe is a flat-faced insulated cylinder with the collector surface at the tip, and is water-cooled. The probe was tested in a laboratory flame and in small-scale rocket motor exhausts at the Naval Research Laboratory, and performed well both thermally and electrically. The analytical procedure for interpreting probe measurements was based on Lam's generalized continuum theory. The theory was verified in laboratory flames of known ionization levels. Positive ion and electron densities were measured in small-scale aluminized composite solid-propellant rocket motor exhausts at NRL. Tests in full-scale, sea-level rocket motor exhausts were performed, and positive ion densities in general agreement with theoretical predictions were obtained. It is concluded that local values of charged species concentrations in solid-propellant rocket motor exhausts can be obtained with a stagnation point electrostatic probe.

Some new results on space shuttle atmospheric ascent optimization

Abstract: Atmospheric ascent optimal trajectories for medium to high lift drag ratio space shuttle type rocket vehicles

Single chamber rap having centerport inhibitor

Abstract: A rocket assisted projectile has a solid propellant charge within the projectile casing extending substantially throughout the length of the casing and has an inhibited centerport therein which axially extends substantially throughout the length of the propellant charge, and the solid propellant charge comprises a cast single explosive sensitized charge bonded to the casing and bonded to the inhibitor material of the inhibited centerport during cure of the cast charge with said charge having bifunctional characteristics to produce rocket thrust for the projectile in flight and high explosive blast of the projectile at target.

Rocket & launcher assembly with thrust adjustment

Abstract: A rocket and launcher assembly is disclosed, presettable to provide in the rocket discharged therefrom a thrust level in accordance with the height or range desired to be attained by said rocket. A rotatable sealing plate in the rocket may be manually adjusted prior to propellant ignition to direct propellant gases through one or another of several nozzle groups in a nozzle plate separated from the propellant by the sealing plate. The various nozzle groups are canted or otherwise configured to provide the varying thrust from group to group.

Delta squib circuit

Abstract: An electroexplosive device disposed for energization for creating a spark flame and/or gaseous discharge which is utilized to perform a work function such as igniting the propellant igniter in a rocket to initiate launch thereof.

Rocket plume /N2O4/MMH/ impingement on aluminum surface

Abstract: T combustion of bipropellant motors under high-altitude conditions using dinitrogen tetroxide and hydrazine fuels has been reported to result in the formation of nonvolatile residues. The partial oxidation of the fuel is particularly evident during the pulse mode operation of the motor where high-combustion temperatures are not attained. Two major problems resulting from the use of these restartable space environmental engines are the contamination" of vehicle surfaces from bipropellant rocket exhaust products and the occurrence of large transient ignition overpressures, which could have deleterious effects on engine operation. The latter results from the sudden detonation of the combustion residues which had accumulated on the rocket chamber wall. Both problems result from the incomplete combustion of the oxidizer and the fuel. The major product from the partial oxidation of hydrazine type fuels by N204 has been identified as fuel nitrates." Although the chemical nature of the combustion residues has been studied by several investigators, no information is available on the particle size and distribution of residues in the plume. In this study, a polished aluminum bar was placed in the plume of a N2O4-monomethylhydrazine (MMH) bipropellant motor during pulse mode firings under highaltitude conditions to obtain the imprint of residues striking the metal surface at very high velocity.

Spin stabilizing rocket nozzle

Abstract: A rocket nozzle having a plurality of internal vanes located downstream of the nozzle throat for imparting rotational spin to the rocket about its longitudinal axis. Each vane may have a nonablative body having a cross section symmetric with the nozzle axis and a consummable ablative body attached thereto to provide a composite cross section asymmetric to the nozzle axis. The ablative material, imparts spin stabilization to the rocket leaving only the symmetric nonablative vane portions, thus preventing excessive spin rates.

Thrust vector {13 {11 jet interaction vehicle control system

Abstract: A control system for a high speed rocket powered vehicle involving the use of a valve arrangement in which hot gases are received from the motor, and selectively ported overboard or into the rocket nozzle in order to provide maneuvering or vectoring control for the vehicle. In a preferred embodiment, at least one pair of oppositely disposed valves is utilized, with the movable portions of the valves arranged to be relatedly movable such that the vectoring forces provided by the valves are additive. My valves have a neutral position in which no maneuvering forces are generated, with an inherent fail-safe design being involved such that catastrophic maneuvers are prevented in the event control power is lost. Also, inasmuch as my valves do not shut off the hot gas flow, the rocket motor chamber pressure desirably does not fluctuate. Advantageously, the valve construction taught herein can withstand the hot erosive gases emanating from a solid fuel rocket.

High Altitude Air Sampling with a Rocketborne Cryocondenser

Abstract: A rocketborne cryogenic sampler, capable of collecting large, unmodified and uncontaminated high altitude air samples, has been successfully developed, tested and flown. The sampler employs a simple normal shock diffuser inlet and collects a column of air at supersonic speeds during rocket ascent. The sampled air condenses on stainless steel coils cooled with pressurized liquid hydrogen. Some of the experimental applications of this versatile sampling system are discussed. The sampling system, its operation, and its experimental evaluation are described. Preliminary results of the first rocket sampler flight at White Sands Missile Range on 4 September 1968 testify to the fully successful performance of the sampling system.

Rocket assisted projectile

Abstract: A rocket assisted projectile round consisting of a cartridge, a rocket motor and projectile wherein the cartridge propels the rocket motor out of a firing tube and ignites ignition powder in the rocket motor. Thereafter, the rocket motor is ignited and it propels the projectile in flight.