Showing papers on "Rocket published in 1980"

Rocket observations of precipitating electrons over a pulsating aurora

Abstract: Data from the third rocket of the Substorm-GEOS series have been studied. The rocket was launched from ESRANGE on January 27, 1979 at 21.52.20 UT into a pulsating aurora.

Stratospheric Aerosol Modification by Supersonic Transport and Space Shuttle Operations—Climate Implications

Abstract: The potential effects on stratospheric aerosols of supersonic transport emissions of sulfur dioxide gas and submicron soot granules, and space shuttle rocket emissions of aluminum oxide particulates are estimated. An interactive particle-gas model of the stratospheric aerosol layer is used to calculate changes due to exhaust emissions, and an accurate radiation transport model is employed to compute the effect of aerosol changes on the earth's average surface temperature. It is concluded that the release of large numbers of small particles (soot or aluminum oxide) into the stratosphere should not lead to a corresponding significant increase in the concentration of large, optically active aerosols, but that the increase in large particles is severely limited by the total mass of sulfate available to make large particles in situ, and by the rapid loss of small seed particles via coagulation. We find that a fleet of several hundred advanced supersonic aircraft operating daily at 20 km, or the launch of one space shuttle rocket per week, could produce roughly a 20% increase in the large-particle concentration of the stratosphere. We find, in addition, that aerosol increases of this magnitude would reduce the global surface temperature by less than 0.01 K.

Prediction of Rocket Plume Flowfields for Infrared Signature Studies

Abstract: The contribution of various gasdynamic processes affecting rocket exhaust plume structure in the altitude range of 0-60 km is discussed in terms of their relative influence on plume infrared radiation signature predictions. It is demonstrated that spatial details of the nearfield inviscid/shock structure in rocket plumes can appreciably affect flight signature levels at higher altitudes (i.e., /?> 30-40 km). Spatial details are also required in the analysis of most laboratory plumes. Simplified gasdynamic models which globally incorporate the effects of inviscid structure into the startline conditions for a pressure-equilibrated farfield mixing analysis are shown to be adequate in flight signature studies at lower altitudes (i.e., h> 20-30 km). The sensitivities of rocket plume emission to variations in turbulence modeling parameters are presented for flight signature studies at representative lower and higher altitudes in the range of interest. It is demonstrated that, under all conditions, turbulent mixing processes play a dominant role in the prediction of plume signature levels.

Flexible area launch tube rear cover

Abstract: A rear cover for rocket launch tubes providing a seal between the tube and the rear of the rocket. The rocket is arranged in a manner such that the exhaust of a firing rocket will produce a seal between a sealing member and the rear of the rocket and will seal off the portion of the tube adjacent to the rocket itself, thus preventing exhaust gases from entering this portion of the launch tube.

Solar flux variation of the thermospheric molecular oxygen density

Abstract: The paper presents measurements of the thermospheric molecular oxygen density obtained from the Atmosphere Explorer (AE) satellites and composition data obtained from rocket-based experiments which provide information on the distribution of O2 between 120 and 200 km as a function of solar flux. The rocket experiment data can be analyzed for long-term variations, which show that the O2 density at 200 km shows little variation but at 120 km decreases approximately 30% for the F sub 10.7-cm flux.

Tandem rocket launcher

Abstract: A tandem rocket launcher is provided by mounting plural rockets in an elongated launch tube with associated guide and launch equipment for each rocket. A conical shield is placed between the rockets which deflects exhaust gases generated by firing the forward rocket away from the rearward rocket. The shield is then removed by firing of the subsequent rocket or pivoting of two halves of the deflector away from the path of travel of the subsequent rocket.

Hybrid Rocket/Airbreathing Propulsion for Ballistic Space Transportation

Abstract: The potential payload gains due to airbreathing propulsion are evaluated for a one-and-one-half stage reusable vertical-takeoff ballistic space transporter with a gross mass of 155 Mg. The system consists of a returnable ring of turborocket/ramjet engines added as a half-stage to the structure of a 130 Mg, single-stage, vertical-takeoff-vertical-landing, pure-rocket transporter considered in an earlier industry study. High-pressure topping-cycle rockets are used part-time in parallel with the airbreathers, with hydrogen/oxygen propellants used for both. With fixed takeoff mass and airbreathing engines, the main variables were the rocket thrusts and burning times, cycle change and staging points, and the injection angle at 100-m altitude. State-of-the-art technology was assumed. Trajectories free from constraints, except acceleration limits, allowed optimal propulsion system use. Propulsion performance maps, ascent trajectories, and weight breakdowns are given. Payload fractions up to 7.8% of gross mass were obtained for the airbreathing vehicle, which is very high for this size class compared with expendable two-stage rocket transporters.

Mechanical noise suppressor for small rocket motors

Abstract: A noise suppressor for small rocket motors including a plurality of perfoed metal cylinders disposed in concentric relation and secured to a support plate. A noise suppression material is disposed in the chamber of each adjacent cylinder. Noise suppression material is also disposed in the center cylinder and is expelled by the rocket motor thrust. A collar on the support plate secures the motor to the suppressor.

Laboratory studies of the charge neutralization of a rocket payload during electron beam emission

Abstract: The charge neutralization of an electrically-isolated rocket payload emitting an energetic electron beam has been studied in experiments in the large vacuum chamber at Johnson Space Center. The introduction of an RF-discharge-produced ambient plasma density (10,000 to 50,000 per cu cm) reduces the payload potential to 200 V for low current (1 and 10 ma) beams. The ignition of the beam-plasma discharge provides an efficient neutralization process for higher current beams.

The design and combustion performance of practical swirlers for integral rocket/ramjets

Abstract: A method was devised for the design and fabrication of swirl inlet hardware with practical application to the integral rocket/ramjet dump combustor. A total of seven swirl inserts were tested to determine the effects of different swirl profiles on combustor performance. Combustor length-to-diameter ratio (LC/D) was varied between 1.5 and 3, and the ratio of the nozzle throat to combustor area (A*/A3) between 40 and 60%. Combustor wall static distributions were measured in all configurations in which LC/D = 3. Airflow immediately downstream of the swirler was probed in cold flow to determine actual swirl angles to compare with prediction. Combustion instability data was recorded for subsequent spectral analysis by fast Fourier transform.

Launching tower for heavy rockets

Abstract: A system for launching heavy rockets from the shaft of a launching tower where a cluster of liquid-propellant motors is mounted to its base and a series of clusters of solid-propellant motors are mounted in the tower's columns, the latter motors being consecutively upwardly fired. The rocket is supported by a piston impinged by the jet of gases ejected by the tower's motors. The impinging jet of gases spreads out of the shaft through open windows which are provided in the tower's walls and the rising movement of the rocket inside the shaft is controlled along a given path of movement in a manner that the firing of motors and closing of windows ensure controlled pressures below the piston and as a result, controlled accelerations. The rocket leaving the tower disconnects the impinging piston and then fires its own motors, having at that point a kinetic energy greater than usual. Heavy rockets using the launching tower can put in their orbits useful loads much greater than usual due to the load of propellants and their tanks saved in the first stage of thrust.

Some Considerations on the Antimatter and Fusion RAM Augmented Interstellar Rocket

Abstract: Some aspects of the ram augmented interstellar rocket (RAIR) are considered for a vehicle without a separate power source. Two fuel modes are studied where either nuclear material or antimatter is added to scooped hydrogen to give vehicle propulsion. A mass ratio is derived and some aspects of the reaction chamber are given.

Rocket assisted projectile and cartridge with time delay ignition and sealing arrangement

Abstract: A cartridge arrangement having a rocket assisted projectile for firing therefrom by ignition of propellant in the cartridge case and for subsequent ignition of a rocket grain within the projectile, in which the projectile has a sealed tubular chamber cavity encompassing a tubular or ring shaped end burning rocket grain, the rear end of which chamber is formed by a combined nozzle block and rear penetrator support which has nozzle openings sealed by ignitable time delay igniter plugs, and the outer, inner, and forward extremities of which are bounded by a thin-walled projectile case, a cylindrical penetrator, and a forward penetrator support, and which ignitable time delay igniter plugs are externally ignitable by the burning of the propellant to enable subsequent ignition of the adjacent end of the rocket grain.

Coupled-interaction launch behavior of a flexible rocket and flexible launcher

Abstract: A numerical solution is developed for analyzing the coupled dynamic interaction behavior of a thrust-loaded flexible spinning rocket propelled along a flexible launcher. The partial diferential equations of motion describing the dynamic behavior of the system are solved using a hybrid approach. The spatial behavior of the rocket is modeled by the finite-element method as a beam column with sectionally constant cross-section properties, while a summation of the natural mode solutions are used to model the spatial behavior of the launcher. The resulting time-dependent differential equations, which are coupled together by consideration of the time-dependent support forces between the rocket and the launcher, are then numerically integrated in time to obtain the system transient dynamic response. Numerical results are presented which demonstrate the validity of the method and which demonstrate the influence of rocket and launcher bending flexibility on rocket launch attitude and, hence, rocket accuracy. The bending effects are shown to significantly increase unfavorable rocket launch conditions.

Analysis of the measured effects of the principal exhaust effluents from solid rocket motors

Abstract: The feasibility of conducting environmental chamber tests using a small rocket motor to study the physical processes which occur when the exhaust products from solid motors mix with the ambient atmosphere was investigated. Of particular interest was the interaction between hydrogen chloride, aluminum oxide, and water vapor. Several types of instruments for measuring HCl concentrations were evaluated. Under some conditions it was noted that acid aerosols were formed in the ground cloud. These droplets condensed on Al2O3 nuclei and were associated with the rocket exhaust cooling during the period of plume rise to stabilization. Outdoor firings of the solid rocket motors of a 6.4 percent scaled model of the space shuttle were monitored to study the interaction of the exhaust effluents with vegetation downwind of the test site. Data concerning aluminum oxide particles produced by solid rocket motors were evaluated.

Rocket attitude control apparatus

Abstract: For controlling the attitude of a rocket including a rocket fuselage and a thrust nozzle integrally attached to the rear end of the rocket fuselage and having a nozzle throat located longitudinally intermediate thereof, a rocket attitude control apparatus comprises a plurality of thrust vector control units disposed at the outer periphery of the thrust nozzle between the nozzle throat and the rear end of the thrust nozzle in circumferentially equiangularly spaced relationship to each other, and each including a fluid injecting nozzle projectable and retractable into and out of the thrust nozzle and having an injecting bore therein, wherein said fluid injecting nozzle is permitted to project into the thrust nozzle while being cooled by fluid injected from the injecting bore into the thrust nozzle. The projection of the fluid injecting nozzle causes a stream of combustion gas passing through the thrust nozzle to be partially disturbed for controlling the attitude of the rocket.

Turbulent flow analysis of erosive burning of cylindrical composite solid propellants

Abstract: An axisymmetric turbulent boundary layer was analyzed in order to investigate erosive burning in composite solid-propellant rocket motors. It was found that there is a strong interaction between the core flow acceleration and turbulence level in the boundary layer. The increase of turbulence near the surface of the propellant plays an important role in the erosive burning mechanism. Reducing the port diameter makes a rocket motor more sensitive to erosive burning. When the port diameter is uniform, the erosive burning rate increases toward the aft end of the rocket motor. This trend is less pronounced or even reversed when the port diameter is divergent.