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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 757 records · Page 42
All sourcesNASA NTRSDOE OSTI
NASA NTRS1974

An investigation of wave-particle interactions and particle dynamics using electron beams injected from sounding rockets

Electrons with energy up to 40 kV have been injected into semi-trapped orbits from sounding rockets at Wallops Island, Virginia, and at Fort Churchill, Manitoba, Canada. By directing the rocket trajectory to have a horizontal component which in direction and speed matched the bounce displacement of the injected electrons, it was possible to detect conjugate echoes at Wallops and possibly at Churchill, and to study the distribution of the echoes in space, time and energy. By combining observations of many echoes, a composite picture can be obtained of the beam patterns. Atmospheric scattering at the conjugate point of Wallops Island has been extensively studied, and the process produces a scale width of 5-10 m, but with an echo intensity which is only 10% of theoretical estimates.

Winckler, J. R.↗
NASA NTRS1974

Skylab Apollo Telescope Mount Calibration Rocket Project

The Calibration Rocket (CALROC) Project was established to provide calibration data for the Harvard College Observatory (S055) and the Naval Research Laboratory (S082) ultraviolet solar experiments on Skylab to provide compensation for any change in performance during the long mission in the space environment after the preflight calibration. The calibration instruments were smaller-scale, lighter-weight, but similar in performance to the S055 and S082 experiments. They were launched on Black Brant VC sounding rockets from White Sands Missile Range, New Mexico. The CALROC instruments were calibrated before launch and verified after flight. Each flight obtained approximately four minutes of data on an area of the sun which was then observed by the Skylab astronauts with the ATM experiments on three successive orbits.

Frank, M. W.↗
NASA NTRS1974

Prediction of pressure and flow transients in a gaseous bipropellant reaction control rocket engine

An analytic model is developed to predict pressure and flow transients in a gaseous hydrogen-oxygen reaction control rocket engine feed system. The one-dimensional equations of momentum and continuity are reduced by the method of characteristics from partial derivatives to a set of total derivatives which describe the state properties along the feedline. System components, e.g., valves, manifolds, and injectors are represented by pseudo steady-state relations at discrete junctions in the system. Solutions were effected by a FORTRAN IV program on an IBM 360/65. The results indicate the relative effect of manifold volume, combustion lag time, feedline pressure fluctuations, propellant temperature, and feedline length on the chamber pressure transient. The analytical combustion model is verified by good correlation between predicted and observed chamber pressure transients. The developed model enables a rocket designer to vary the design parameters analytically to obtain stable combustion for a particular mode of operation which is prescribed by mission objectives.

Markowsky, J. J.↗
NASA NTRS1974

Theoretical investigation of nonlinear three-dimensional instabilities in liquid rockets with real nozzles

An approximate analytical technique has been developed for the solution of nonlinear three-dimensional, transverse and axial combustion-instability problems that are frequently observed in liquid-propellant rocket motors. This theory is an extension and generalization of previous analyses, which could analyze either transverse or axial instabilities in liquid combustors with quasi-steady nozzles, to the practical situations of three-dimensional instabilities in combustors with conventional DeLaval nozzles. Unlike the quasi-steady nozzle, the presence of a conventional nozzle imposes restrictions upon the behavior of both the amplitudes and phases of the oscillations at the nozzle entrance plane. The applicability of the solution technique, which is based on the Galerkin method, is demonstrated by analyzing the nonlinear stability of a cylindrical liquid-rocket combustor with uniform injection of propellants at one end and a conventional nozzle at the other end. Crocco's pressure-sensitive time-lag model is used to describe the unsteady combustion process.

Powell, E. A.↗
NASA NTRS1974

Reentry aerodynamic characteristics of a space shuttle solid rocket booster model 449 tested in MSFC 14 by 14 inch TWT (SA26F)

Force tests of a 0.563 percent scale space shuttle solid rocket booster (SRB) model, MSFC Model 449, were conducted at the Marshall Space Flight Center 14 x 14 inch Trisonic Wind Tunnel. There were a total of 134 runs (pitch polars) made. Test Mach numbers were 0.6, 0.9, 1.2, 1.96, 2.74, 3.48, 4.00, 4.45, and 4.96; test angles of attack ranged from minus 10 degrees to 190 degrees; test Reynolds numbers ranged from 4.9 million per foot to 7.1 million per foot; and test roll angles were 0, 45, 90, and 135 degrees. The model was tested with three different engine nozzle/skirts. Two of these engine configurations differed from each other in the magnitude of the volume inside the nozzle and skirt. The third engine configuration had part of the nozzle removed. The model was tested with an electrical tunnel in combination with separation rockets of two different heights.

Johnson, J. D.↗
NASA NTRS1974

Status of flow separation prediction in liquid propellant rocket nozzles

Flow separation which plays an important role in the design of a rocket engine nozzle is discussed. For a given ambient pressure, the condition of no flow separation limits the area ratio and, therefore, the vacuum performance. Avoidance of performance loss due to area ratio limitation requires a correct prediction of the flow separation conditions. To provide a better understanding of the flow separation process, the principal behavior of flow separation in a supersonic overexpanded rocket nozzle is described. The hot firing separation tests from various sources are summarized, and the applicability and accuracy of the measurements are described. A comparison of the different data points allows an evaluation of the parameters that affect flow separation. The pertinent flow separation predicting methods, which are divided into theoretical and empirical correlations, are summarized and the numerical results are compared with the experimental points.

Schmucker, R. H.↗
NASA NTRS1975

Characteristics of response factors of coaxial gaseous rocket injectors

The results of an experimental investigation undertaken to determine the frequency dependence of the response factors of various gaseous propellant rocket injectors subject to axial instabilities are presented. The injector response factors were determined, using the modified impedance-tube technique, under cold-flow conditions simulating those observed in unstable rocket motors. The tested injectors included a gaseous-fuel injector element, a gaseous-oxidizer injector element and a coaxial injector with both fuel and oxidizer elements. Emphasis was given to the determination of the dependence of the injector response factor upon the open-area ratio of the injector, the length of the injector orifice, and the pressure drop across the injector orifices. The measured data are shown to be in reasonable agreement with the corresponding injector response factor data predicted by the Feiler and Heidmann model.

Janardan, B. A.↗
NASA NTRS1975

Reentry static stability characteristics of a (Model 471) .005479-scale 146-inch solid rocket booster tested in the NASA/MSFC 14 by 14 inch TWT (SA8F)

A force test of a scale model of the Space Shuttle Solid Rocket Booster was conducted in a trisonic wind tunnel. The model was tested with such protuberances as a camera capsule, electrical tunnel, attach rings, aft separation rockets, ET attachment structure, and hold-down struts. The model was also tested with the nozzle at gimbal angles of 0, 2.5, and 5 degrees. The influence of a unique heat shield configuration was also determined. Some photographs of model installations in the tunnel were taken and are included. Schlieren photography was utilized for several angles of attack.

Johnson, J. D.↗
NASA NTRS1975

Study for application of a sounding rocket experiment to spacelab/shuttle mission

An inexpensive adaptation of rocket-size packages to Spacelab/Shuttle use was studied. A two-flight project extending over two years was baselined, requiring 80 man-months of effort. It was concluded that testing should be held to a minimum since rocket packages seem to be able to tolerate shuttle vibration and noise levels. A standard, flexible control and data collection language such as FORTH should be used rather than a computation language such as FORTRAN in order to hold programming costs to a minimum.

Code, A. D.↗
NASA NTRS1974

Expendable solid rocket motor upper stages for the Space Shuttle

A family of expendable solid rocket motor upper stages has been conceptually defined to provide the payloads for the Space Shuttle with performance capability beyond the low earth operational range of the Shuttle Orbiter. In this concept-feasibility assessment, three new solid rocket motors of fixed impulse are defined for use with payloads requiring levels of higher energy. The conceptual design of these motors is constrained to limit thrusting loads into the payloads and to conserve payload bay length. These motors are combined in various vehicle configurations with stage components derived from other programs for the performance of a broad range of upper-stage missions from spin-stabilized, single-stage transfers to three-axis stabilized, multistage insertions. Estimated payload delivery performance and combined payload mission loading configurations are provided for the upper-stage configurations.

Davis, H. P.↗
NASA NTRS1975

Properties of the wake of small Langmuir probes on sounding rockets

Split Langmuir probes have been used to study the near wake of small Langmuir probes on sounding rockets. Experiments have been performed on two rocket flights using planar disk and cylindrical geometries, and the results are presented. Significant wake perturbations in plasma density and temperature were found due to the probe body itself, even though the probes were of the order of or smaller than the Debye length. The largest effects of the wake are seen in the electron collection characteristics of the probe. The wake of small probes show apparent magnetic field aligned structure, even though the probes were much smaller than the ion gyroradius. On one flight, a space charge potential large enough to substantially alter photoemission, -3.5 volts, was observed.

Bering, E. A.↗
NASA NTRS1974

Investigation of electron dynamics in the magnetosphere with electron beams injected from sounding rockets

This paper describes an empirical study of the basic mechanisms by which electrons precipitate from the geomagnetic field to produce 'auroral X rays' during periods of geomagnetic activity. The study was based on data obtained by the Echo satellites. Echo I, launched in 1970, injected 40 keV, 0.1 amp electron pulses at low latitude (L ? 2.6) and successfully measured the returning pulses from the conjugate region. Electric fields and multiple Coulomb scattering were studied. Echo II, launched in 1972 from high latitude (L ? 8) studied the interaction of the beams with background radiation and the detailed motion of the beams near the rocket. Evidence for a beam plasma instability was obtained. Echo III launched in April 1974, (L ? 5.5) detected a series of conjugate echoes during the presence of a strong convective field in the magnetosphere. It was shown that the electric field measurement in the ionosphere using the incoherent backscatter radar and detectors on the rocket was transferred to the equatorial plane as though field lines were equipotentials.

Winckler, J. R.↗
NASA NTRS1975

Selection of artificial gravity by animals during suborbital rocket flights

White rats selected preferred artificial gravity levels by locomotion in centrifuges consisting of two runways mounted in the nose of sounding rockets. Roll rate of the Aerobee 150A rocket was designed to produce an angular velocity of 45 rpm during 5 min of free-fall, providing a gravity range from 0.3 to 1.5 G depending on a subject's runway position. One animal was released at the high and one at the low gravity position in each flight. Animal positions were continuously recorded. Locomotion patterns during these flights were similar. All four animals explored the entire available G-range. One rat settled at 0.4 G after 2 min; the others crossed the 1-G location in progressively narrower excursions and were near earth gravity at the end of the test period. Tentatively, the data suggest that normal earth-reared rats select earth gravity when available magnitudes include values above and below 1 G. Modification of gravity preference by prolonged exposure to higher or lower levels remains a possibility.

Lange, K. O.↗
NASA NTRS1974

Studies of exhaust products from solid propellant rocket motors fired in an environmental chamber

Experiments are described in which it was attempted to define the state of HCl when rocket motors using ammonium perchlorate and powdered aluminum filler in the fuel system are fired under various relative humidity conditions. A small, variable load rocket motor was developed so that controlled quantities of exhaust products could be produced in an environmental chamber. A technique is described for distinguishing the difference between HCl existing as a gas or existing as an acid aerosol.

Dawbarn, R.↗
NASA NTRS1975

Simultaneous investigation of parent electrons and bremsstrahlung X rays by rocket-borne detectors

Simultaneous measurements of the energy spectrum of precipitating electrons and the resulting bremsstrahlung X-ray spectrum were carried out during an auroral event on March 3, 1971, at the Churchill Research Range, Manitoba, Canada. The electron data were obtained with detectors on a Black Brant VB sounding rocket (275-km apogee), while the X-ray flux was measured by an instrument package that was boosted to 60 km on an Arcas rocket. The X-ray package was deployed on a parachute at apogee to provide a slow descent through the atmosphere. Thick-target bremsstrahlung theory is used to calculate the X-ray flux produced by the incident electrons, and a Monte Carlo method is used to predict the X-ray spectrum at various altitudes appropriate for comparison with the measured X-ray data. Satisfactory agreement between theory and experiment is obtained, and the value of the constant in the thick target theory has been estimated to be about 0.00002.

Vij, K. K.↗
NASA NTRS1975

Preliminary assessment of the potential impact of solid-fueled rocket engines in the stratosphere

Free chlorine atoms produced from HCl deposited by solid-fueled rocket engines react to destroy odd oxygen in the stratosphere. Using a one-dimensional photochemical model, we have computed the reduction of ozone likely to be caused by long-term operation of such vehicles powered by large solid-fueled rocket engines. It is likely that ozone reduction will not be greater than a few tenths of a per cent, although the value is dependent upon ambient NO(x) concentrations.

Whitten, R. C.↗
NASA NTRS1975

Tailoff thrust and impulse imbalance between pairs of Space Shuttle solid rocket motors

The tailoff thrust and impulse imbalance between pairs of solid rocket motors is of particular interest for the Space Shuttle Vehicle because of the potential control problems that exist with this asymmetric configuration. Although a similar arrangement of solid rocket motors was utilized for the Titan Program, they produced less than one-half the thrust level of the Space Shuttle at web action time, and the overall vehicle was symmetric. Since the Titan Program does provide the most applicable actual test data, 23 flight pairs were analyzed to determine the actual tailoff thrust and impulse imbalance experienced. The results were scaled up using the predicted web action time thrust and tailoff time to arrive at values for the Space Shuttle. These values were then statistically treated to obtain a prediction of the maximum imbalance one could expect to experience during the Shuttle Program.

Jacobs, E. P.↗
NASA NTRS1975

Designing for solid rocket booster reusability

The Solid Rocket Booster (SRB) of the Space Shuttle Program has been designed to be recovered, refurbished, and reused up to 19 times on subsequent launches. The design modifications to the SRB to incorporate this capability include the addition of a parachute recovery system and minor structural modifications to the nose cone, forward skirt, aft skirt, and solid rocket motor structures for withstanding the water impact loading. In addition, the detail design of subsystem hardware requires careful attention to corrosion prevention and facility of refurbishment operations. A cost analysis comparing the reusable SRB with an expendable version shows a substantial reduction in Space Shuttle cost per flight is achieved with the reusable design approach.

Nevins, C. D.↗