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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 163 records · Page 9
All sourcesNASA NTRSDOE OSTI
NASA NTRS1974

Second heated jettison test on the Centaur standard shroud

The second in a planned series of heated jettison tests on the Centaur Standard Shroud was conducted on January 16, 1974. The first 250-second portion of the test sequence involved heating the shroud with a specially-built fixture designed to provide a simulation of the heating environment encountered by the shroud during its ascent through the earth's atmosphere. The two heater halves, which were mounted on a rail system, were then retracted. This was followed by the jettison of the two shroud halves into catch nets positioned at 90 deg to the heater rails. The condition which made this test unique compared to the others in the test series was the alignment of the maximum thermal line with the shroud separation plane. Information on the test hardware, configuration, and sequence is presented. Shroud thermal and deflection data encountered during the heating portion of the test sequence are compared with free-skin design temperatures in various graphical formats.

Source record↗
NASA NTRS1974

Centaur Standard Shroud (CSS) full jettison test dynamic analysis

During the space power facility jettison tests, the non-domed half of the Centaur standard shroud was allowed to completely separate from its hinge connection and was caught in a horizontal catch net. A rigid body dynamic analysis that was performed to predict the half shroud prior to and after net contact is presented. Analytical predictions of the longitudinal and circumferential bending moments imposed on the half shroud by the catch net and the net pressure on the half shroud corrugated skin are also presented.

Kasper, H. J.↗
NASA NTRS1973

Centaur D-1T propulsion and propellant systems

Modifications are described which have been introduced to the Centaur high-energy upper stage (which is being integrated with the Titan IIIC booster) to improve mission flexibility and reliability, and to provide three-burn synchronous orbit capability. The addition of a sidewall radiation shield significantly reduces heat transfer to the liquid hydrogen tank. This radiation field, in conjunction with a newly developed computer controlled propellant tank venting and pressurization system, permits the use of improved techniques for propellant management during orbital coast. Some minor changes in the propulsion and propellant systems which were necessary to adapt these systems for synchronous orbit trajectories are described, together with the redundancy incorporated to reduce the number of single failure points.-

Goette, W. E.↗
NASA NTRS1975

Centaur propellant acquisition system study

A study was performed to determine the desirability of replacing the hydrogen peroxide settling system on the Centaur D-1S with a capillary acquisition system. A comprehensive screening was performed to select the most promising capillary device fluid acquisition, thermal conditioning, and fabrication techniques. Refillable start baskets and bypass feed start tanks were selected for detailed design. Critical analysis areas were settling and refilling, start sequence development with an initially dry boost pump, and cooling the fluid delivered to the boost pump in order to provide necessary net position suction head (NPSH). Design drawings were prepared for the start basket and start tank concepts for both LO2 and LH2 tanks. System comparisons indicated that the start baskets using wicking for thermal conditioning, and thermal subcooling for boost pump NPSH, are the most desirable systems for future development.

Blatt, M. H.↗
NASA NTRS1975

Wind tunnel investigation of a Centaur standard shroud compartment vent from Mach number of 0.70 to 1.96

An experimental investigation was conducted in the Lewis Research Center 8- by 6-foot supersonic wind tunnel to determine the vent discharge coefficient for the Centaur standard shroud/liquid hydrogen tank compartment vent. The test was conducted from Mach 0.70 to 1.96 with the vent mounted in a flat plate. Full scale simulated flight hardware, such as the vent, corrugations, aft field joint ring and ice bag clip was used. Air was discharged from a plenum chamber, located on the tunnel sidewall behind the plate, through five 6.35 cm diameter vent orifices into the free stream. Boundary layer thickeners, analytically predicted displacement thickness for the vehicle nominal flight trajectory could be simulated over the Mach number range. The highest vent discharge coefficient for any given Mach number and vent pressure ratio generally occurred at the maximum displacement thickness.

Johns, A. L.↗
NASA NTRS1975

Centaur Standard Shroud (CSS) Heated Altitude Jettison Tests

Altitude jettison tests, at a pressure of 20 torr (0.39 psia), were performed on the Centaur Standard Shroud (CSS) in a 100-foot diameter vacuum chamber. These jettison tests were part of a series of flight qualification tests which were performed on the new CSS system in preparation for the Helios and Viking missions. The first two tests subjected the CSS to a thermal cycle which simulated aerodynamic heating during ascent flight and the third test was performed at altitude pressure and in ambient temperature conditions. The purpose of the ambient temperature test was to provide base line data by which the separate machanical and thermal factors that influence jettison performance could be evaluated individually. The CSS was successfully jettisoned in each of the three tests. Also, thermal, stress, and structural deflection data were obtained which verified the analytical predictions of CSS response to flight environmental conditions and performance during jettison. In addition, much important information was obtained on critical CSS-to-payload clearance losses due to shell motions prior to and during jettison. The effectiveness of the separation system was successfully demonstrated at maximum flight temperatures.

Source record↗
NASA NTRS1976

Experimental measurements of the ground cloud growth during the 11 February 1974, Titan-Centaur launch at Kennedy Space Center

The Titan-Centaur was launched from Kennedy Space Center on February 11, 1974 at 0948 eastern daylight time. Ground level effluent measurements were obtained from the solid rocket motors for comparison with NASA diffusion models for predicting effluent ground level concentrations and cloud behavior. The results obtained provide a basis for an evaluation of such key model inputs such as cloud rise rate, stabilization altitude, crosswind growth, volume expansion, and cloud trajectory. Ground level effluent measurements were limited because of changing meteorological conditions, incorrect instrument location, and operational problems. Based on the measurement results, operational changes are defined. Photographs of the ground exhaust clouds are shown. The chemical composition of the exhaust gases was analyzed and is given.

Stewart, R. B.↗
NASA NTRS1976

Centaur boost pump turbine icing investigation

An investigation was conducted to determine if ice formation in the Centaur vehicle liquid oxygen boost pump turbine could prevent rotation of the pump and whether or not this phenomenon could have been the failure mechanism for the Titan/Centaur vehicle TC-1. The investigation consisted of a series of tests done in the LeRC Space Power Chamber Facility to evaluate evaporative cooling behavior patterns in a turbine as a function of the quantity of water trapped in the turbine and as a function of the vehicle ascent pressure profile. It was found that evaporative freezing of water in the turbine housing, due to rapid depressurization within the turbine during vehicle ascent, could result in the formation of ice that would block the turbine and prevent rotation of the boost pump. But for such icing conditions to exist it would be necessary to have significant quantities of water in the turbine and/or its components, and the turbine housing temperature would have to be colder than 40 F at vehicle liftoff.

Rollbuhler, R. J.↗
NASA NTRS1976

Compendium of meteorological data for the Centaur launch in February 1974

The meteorological data for the 33-hour period prior to the Centaur (Titan III E) launch from Kennedy Space Center at 0948 EDT on February 11, 1974, are archived in this report. These data were collected in support of the NASA rocket exhaust effluent prediction and monitoring program. This is a rather unique data set in that a high temporal resolution of upper air soundings is provided. All supporting data, such as synoptic charts and wind tower data, are also included. This is the second in a series of seven data reports.

Stephens, J. B.↗
NASA NTRS1978

Boundary layer analysis of a Centaur standard shroud

An analytical boundary layer investigation was carried out in conjunction with an experimental wind tunnel test to determine the discharge characteristics of the Centaur shroud ascent vent system on the Titan/Centaur launch vehicle. This involved estimating the effect of the local boundary layers on the vent discharge for vehicle Mach numbers ranging from 0.8 to 1.56. The growth of the boundary layer along the vehicle was influenced by the interaction with flanges protruding into the flow and by the longitudinal corrugations in the vehicle surface. The effects of the flange and corrugations were treated by approximate techniques. In addition, boundary layer calculations were made for a 3 percent model of the launch vehicle compared with experimental results.

Hingst, W. R.↗
NASA NTRS1977

ADDJUST - An automated system for steering Centaur launch vehicles in measured winds

ADDJUST (Automatic Determination and Dissemination of Just-Updated Steering Terms) is an automated computer and communication system designed to provide Atlas/Centaur and Titan/Centaur launch vehicles with booster-phase steering data on launch day. Wind soundings are first obtained, from which a smoothed wind velocity vs altitude relationship is established. Design for conditions at the end of the boost phase with initial pitch and yaw maneuvers, followed by zero total angle of attack through the filtered wind establishes the required vehicle attitude as a function of altitude. Polynomial coefficients for pitch and yaw attitude vs altitude are determined and are transmitted for validation and loading into the Centaur airborne computer. The system has enabled 14 consecutive launches without a flight wind delay.

Swanson, D. C.↗
NASA NTRS1979

Acoustic response of thin film windows in the environment of an Atlas-Centaur launch

An exhaustive design development study was performed to correlate the survivability of thin film to various parameters. Film material properties, film thicknesses, unsupported window areas, window aspect ratios, film/frame transitions, film reinforcing techniques, and material grain orientations were all considered. Several thin films were tested to acoustical loads which are expected during an Atlas-Centaur launch of the High Energy Astronomy Observatory Satellites (HEAO)

Mastronardi, R.↗
NASA NTRS1982

Development of STS/Centaur failure probabilities liftoff to Centaur separation

The results of an analysis to determine STS/Centaur catastrophic vehicle response probabilities for the phases of vehicle flight from STS liftoff to Centaur separation from the Orbiter are presented. The analysis considers only category one component failure modes as contributors to the vehicle response mode probabilities. The relevant component failure modes are grouped into one of fourteen categories of potential vehicle behavior. By assigning failure rates to each component, for each of its failure modes, the STS/Centaur vehicle response probabilities in each phase of flight can be calculated. The results of this study will be used in a DOE analysis to ascertain the hazard from carrying a nuclear payload on the STS.

Hudson, J. M.↗
NASA NTRS1982

Project Centaur

The National Aeronautics and Space Administration (NASA) and the Canada Centre for Space Science, National Research Council of Canada (NRCC), conducted a cooperative sounding rocket campaign in the Canadian Arctic during November/December 1981. The objective of the campaign was to investigate the earth's dayside magnetic cleft region. The project was named CENTAUR for Cleft Energetics Transport and Ultraviolet Radiation. Remote launch support facilities were established at Cape Parry, NWT, Canada (70 deg 10 min N latitude, 124 deg 40 min W longitude). The cleft region is accessible from this location when launched poleward during reasonably quiet magnetic activity. Five large sounding rockets were launched (3 NASA, 2 NRCC). About 30 scientific experiments were launched, and an extensive array of ground based experiments was established at Cape Parry and at Sachs Harbour, Banks Island, 130 miles poleward. This paper discusses the unique organization, planning, facilities, instrumentation, and operation required to support the campaign, and looks briefly at the results.

Brence, W. A.↗