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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 523 records · Page 29
All sourcesNASA NTRSDOE OSTI
NASA NTRS1975

Results of an external tank separation test in AEDC/VKF tunnel B on 0.010-scale replica of space shuttle vehicle model 52-OT(IA17A), Volume 1

Tests were conducted on scale models of the space shuttle orbiter and external tank (ET) to determine the aerodynamic interactions during a return to launch site abort separation. The orbiter model was built to vehicle 3 configuration lines (139B) and the ET model approximated the vehicle 5 configurations with protuberances and attach hardware. For these investigations the orbiter was mounted on the primary support system and the external tank was mounted on the captive trajectory system. Six-component data were obtained for each vehicle at various orbiter angles of attack and sideslip for a range of relative angular and linear displacements of the ET from the orbiter.

Spangler, R. H.↗
NASA NTRS1974

The Space Shuttle - Key considerations

Typical Space Shuttle flight operations, including launch/insertion, on-orbit operations, de-orbit, and ground turnaround, are summarized. The orbiter, main engine, and solid rocket boosters will be reusable. The Shuttle will be able to abort ascent and return the orbiter plus payload to the launch site if necessary. Mission capabilities include a 7-30 day duration, crew of 4-7 (with 1-4 payload specialists), and 14,500-29,500 kg payloads. Payload accommodations, including cabin, crew provisions, pointing and position stability, thermal constraints, electric power, communications, payload deployment and retrieval, contamination control, and kits for extended missions, are considered. The Thermal Protection System, utilizing pyrolized carbon and silica tiles, is described. The Space Shuttle Main Engine design and performance are considered and compared to those of the J-2 engine used on Saturn/Apollo missions.

Malkin, M. S.↗
NASA NTRS1975

Surface tension propellant acquisition system technology for Space Shuttle reaction control tanks

A program was conducted to provide the technology base for the SS/RCS flight tankage. Through a combination of analysis, subscale testing and computer predictions, a surface tension acquisition/expulsion system design was developed for the Orbiter RCS application. A full-scale tank system was fabricated and ground verification testing was conducted. Cleaning, inspection, fill and drain, and one-g expulsion performance were demonstrated. Results show that the fine-mesh screen, compartmented tank system provides the performance, flexibility, reusability, and other characteristics required by the pulsing, high flowrate RCS. It provides the required expulsion under widely differing high-g boost abort and reentry vectors oriented 119 deg apart and during on-orbit operation under omnidirectional low-g conditions.

Fester, D. A.↗
NASA NTRS1976

Peak-acceleration limiter

Statistical limiter, which protects test specimens during random vibration testing, differentiates between peak acceleration levels that are normal components of vibration signal and those that exhibit damaging characteristics. Device aborts test only when statistical properties of vibration signal change significantly or when catastrophic transient occurs.

Woodbury, R. C.↗
NASA NTRS1976

Fail-safe hydraulic shaker protection

Nine channel system controls acceleration and force on structure undergoing vibration stress testing. System has automatic and manually operative abort feature.

Woodbury, R. C.↗
NASA NTRS1975

Space shuttle orbiter reaction control system jet interaction study

The space shuttle orbiter has forward mounted and rear mounted Reaction Control Systems (RCS) which are used for orbital maneuvering and also provide control during entry and abort maneuvers in the atmosphere. The effects of interaction between the RCS jets and the flow over the vehicle in the atmosphere are studied. Test data obtained in the NASA Langley Research Center 31 inch continuous flow hypersonic tunnel at a nominal Mach number of 10.3 is analyzed. The data were obtained with a 0.01 scale force model with aft mounted RCS nozzles mounted on the sting off of the force model balance. The plume simulations were accomplished primarily using air in a cold gas simulation through scaled nozzles, however, various cold gas mixtures of Helium and Argon were also tested. The effect of number of nozzles was tested as were limited tests of combined controls. The data show that RCS nozzle exit momentum ratio is the primary correlating parameter for effects where the plume impinges on an adjacent surface and mass flow ratio is the parameter where the plume interaction is primarily with the external stream. An analytic model of aft mounted RCS units was developed in which the total reaction control moments are the sum of thrust, impingement, interaction, and cross-coupling terms.

Rausch, J. R.↗
NASA NTRS1975

An experimental investigation of the NASA space shuttle external tank at hypersonic Mach numbers

Pressure and heat transfer tests were conducted simulating flight conditions which the space shuttle external tank will experience prior to break-up. The tests were conducted in the Calspan 48-inch Hypersonic Shock Tunnel and simulated entry conditions for nominal, abort-once-around (AOA), and return to launch site (RTLS) launch occurrences. Surface pressure and heat-transfer-rate distributions were obtained with and without various protuberences (or exterior hardware) on the model at Mach numbers from 15.2 to 17.7 at angles of attack from -15 deg to -180 deg and at several roll angles. The tests were conducted over a Reynolds number range from 1300 to 58,000, based on model length.

Wittliff, C. E.↗
NASA NTRS1975

Genetic technology: Promises and problems

Issues concerning the use of genetic technology are discussed. Some areas discussed include treating genetic disease, prenatal diagnosis and selective abortion, screening for genetic disease, and genetic counseling. Policy issues stemming from these capabilities are considered.

Frankel, M. S.↗
NASA NTRS1975

The NATA code; theory and analysis. Volume 2: User's manual

The NATA code is a computer program for calculating quasi-one-dimensional gas flow in axisymmetric nozzles and rectangular channels, primarily to describe conditions in electric archeated wind tunnels. The program provides solutions based on frozen chemistry, chemical equilibrium, and nonequilibrium flow with finite reaction rates. The shear and heat flux on the nozzle wall are calculated and boundary layer displacement effects on the inviscid flow are taken into account. The program contains compiled-in thermochemical, chemical kinetic and transport cross section data for high-temperature air, CO2-N2-Ar mixtures, helium, and argon. It calculates stagnation conditions on axisymmetric or two-dimensional models and conditions on the flat surface of a blunt wedge. Included in the report are: definitions of the inputs and outputs; precoded data on gas models, reactions, thermodynamic and transport properties of species, and nozzle geometries; explanations of diagnostic outputs and code abort conditions; test problems; and a user's manual for an auxiliary program (NOZFIT) used to set up analytical curvefits to nozzle profiles.

Bade, W. L.↗
NASA NTRS1976

Microprocessor-based multichannel flutter monitor using dynamic strain gage signals

Two microprocessor-based multichannel monitors for monitoring strain gage signals during aerodynamic instability (flutter) testing in production type turbojet engines were described. One system monitors strain gage signals in the time domain and gives an output indication whenever the signal amplitude of any gage exceeds a pre-set alarm or abort level for that particular gage. The second system monitors the strain gage signals in the frequency domain and therefore is able to use both the amplitude and frequency information. Thus, an alarm signal is given whenever the spectral content of the strain gage signal exceeds, at any point, its corresponding amplitude vs. frequency limit profiles. Each system design is described with details on design trade-offs, hardware, software, and operating experience.

Smalley, R. R.↗
NASA NTRS1976

Thruster endurance test

A test system was built and several short term tests were completed. The test system included, in addition to the 30-cm ion thruster, a console for powering the thruster and monitoring performance, a vacuum facility for simulating a space environment, and a storage and feed system for the thruster propellant. This system was used to perform three short term tests (one 100-hour and two 500-hour tests), an 1108-hour endurance test which was aborted by a vacuum facility failure, and finally the 10,000-hour endurance test. In addition to the two 400 series thrusters which were used in the short term and 1100-hour tests, four more 400 series thrusters were fabricated, checked out, and delivered to NASA. Three consoles similar to the one used in the test program were also fabricated and delivered.

Collett, C.↗
NASA NTRS1975

RTLS entry load relief parameter optimization

The results are presented of a study of a candidate load relief control law for use during the pullup phase of Return-to-Launch-Site (RTLS) abort entries. The control law parameters and cycle time which optimized performance of the normal load factor limiting phase (load relief phase) of an RTLS entry are examined. A set of control law gains, a smoothing parameter, and a normal force coefficient curve fit are established which resulted in good load relief performance considering the possible aerodynamic coefficient uncertainties defined. Also, the examination of various guidance cycle times revealed improved load relief performance with decreasing cycle time. A .5 second cycle provided smooth and adequate load relief in the presence of all the aerodynamic uncertainties examined.

Crull, T. J.↗
NASA NTRS1976

Heat transfer test of an 0.006-scale thin-skin thermocouple space shuttle model (50-0, 41-T) in the NASA-Ames Research Center 3.5-foot hypersonic wind tunnel at Mach 5.3 (IH28), volume 1

Data obtained from a heat transfer test conducted on an 0.006-scale space shuttle orbiter and external tank in the NASA-Ames Research Center 3.5-foot Hypersonic Wind Tunnel are presented. The purpose of this test was to obtain data under simulated return-to-launch-site abort conditions. Configurations tested were integrated orbiter and external tank, orbiter alone, and external tank alone at angles of attack of 0, + or - 30, + or - 60, + or - 90, and + or - 120 degrees. Runs were conducted at Mach numbers of 5.2 and 5.3 for Reynolds numbers of 1.0 and 4.0 million per foot, respectively. Heat transfer data were obtained from 75 orbiter and 75 external tank iron-constantan thermocouples.

Cummings, J. W.↗
NASA NTRS1975

Return-to-launch-site trajectory shaping

The results are presented of a study to show the effect on flyback trajectories of constant inertial attitude during the fuel dissipation phase of a return-to-launch-site abort. It is shown that the value of the constant inertial attitude can be chosen to shape the flyback trajectory.

Bown, R. L.↗
NASA NTRS1975

Return-to-launch-site three degree of freedom analysis, constant inertial attitude during the fuel dissipation phase

Results are presented of a study to show the effect of selecting a constant inertial attitude during the fuel dissipation phase of a return-to-launch-site abort. Results are also presented which show that the selection of the constant inertial attitude will affect the arrival point on the range-velocity target line. An alternate selection of the inertial attitude will provide control over the trajectory shape.

Bown, R. L.↗
NASA NTRS1976

Return-to-launch-site variable range-velocity line

The effect of moving the return-to-launch-site (RTLS) range-velocity (R-V) line closer to the landing site was studied. Results are presented which show that a five nautical mile shift in R-V line causes the last RTLS abort to occur approximately one second earlier and that the excess range capability to terminal-area-energy-management interface can be dissipated without an excessive roll angle history.

Bown, R. L.↗
NASA NTRS1975

Integrated auxiliary propulsion for the Space Tug

This paper summarizes the results of a design study which considered several possible methods for applying the liquid-liquid cryogenic oxygen/hydrogen auxiliary propulsion concept to the Space Tug. This concept, which is based on maintaining the propellant in the liquid phase from storage to thruster inlet, is much simpler than previous oxygen/hydrogen systems which converted the propellant to vapor for distribution to the thrusters. The paper describes the selected liquid-liquid concept which is an integrated design that uses the Tug main propulsion tanks as a propellant source. The characteristics of this integrated system are compared with dedicated storable propellant systems. The integrated concept is found to have only slightly superior mission payload performance, but provides inherent vehicle versatility through the interchangeable availability of main and auxiliary propellant. Propellant interchange also was found to permit the auxiliary system to provide abort backup capability in the event of most main engine failures. This capability implies Tug program cost savings which more than offset the higher development costs of the integrated auxiliary propulsion system.

Nichols, J. F.↗
NASA NTRS1976

Technical challenges of integrating the Space Shuttle

A review is presented of the technology involved in integrating the Space Shuttle system. A powered flight analysis of the Shuttle is presented, touching upon the following areas: ascent profile and abort mode integration, sizing and design, control of load factor by a stage thrust shaping, structural load constraints, flight performance reserve and trajectory design for the orbital flight test. A discussion is presented of aerothermodynamics including aerodynamic and plume heating. Flight control and separation is considered with attention paid to liftoff, ascent to booster staging, elevon load relief, booster tailoff thrust mismatch and gimbal limitations and booster separation. Structural analysis and dynamics is examined, considering: vehicle loads and modes and the pogo effect. Propulsion aspects (hydraulics, the LH2 recirculation system, the antigeyser system, the pressurization system, etc.), ground vibration tests, separation system verification and flight readiness firing are all described.

Martin, A. C.↗