Manual attitude control of the lunar module
Manual attitude control for Lunar Module employing directional stability, coordinated turn and attitude command
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Manual attitude control for Lunar Module employing directional stability, coordinated turn and attitude command
Wind tunnel tests of propellor driven, deflected slipstream, short takeoff aircraft model to determine longitudinal and lateral-directional stability when in ground effect
Numerous wind tunnel tests conducted on the evolving delta-wing orbiters have generated a fairly large aerodynamic data base over the entire entry operation range of these vehicles. A limited assessment is made of some of the aerodynamics of the current HO type orbiters, and several specific problem areas selected from the broad data base are discussed. These include, from a subsonic viewpoint, discussions of trim drag effect; effects of the installation of main rocket engine nozzles, OMS and RCS packages, Reynolds number effects, lateral-directional stability characteristics, and landing characteristics.
An early version of an external hydrogen-oxygen tank orbiter was used as a baseline vehicle to experimentally evaluate: (1) nose shape and canopy effects on longitudinal, lateral, and directional stability and trim, and (2) yaw due to aerodynamic roll control at hypersonic speeds. Nose alterations were examined since that part of the vehicle may be subject to modifications because of internal packaging requirements, alleviation of potential high heating areas, and/or possible improvements in aerodynamic stability and control. There was also some concern about the effect of the rather high profile canopy on the aerodynamics; therefore its removal was examined. In addition, roll-yaw coupling was investigated because of its impact on the RCS fuel requirements for entry maneuvers.
An existing deHavilland C-8A airplane has been modified into an augmentor wing flight test vehicle. Research objectives are to verify the augmentor flap concept and to produce data for STOL airworthiness criteria. The Modified C-8A provides the means for jet-STOL flight research down to a 60 knot approach speed. The airplane has a high thrust-to-weight ratio, high-lift flap system, vectored thrust, powerful flight controls, and lateral-directional stability augmentation system. Normal performance and handling qualities are expected to be satisfactory. Analysis and piloted simulator results indicate that stability and control characteristics in conventional flight are rated satisfactory. Handling qualities in the STOL regime are also generally satisfactory, although pilot workload is high about the longitudinal axis.
A series of comparisons made on the longitudinal and lateral directional stability and control characteristics of the baseline 040A space shuttle orbiter configuration is documented. The data used for the comparisons were obtained from five wind tunnel tests conducted in four different wind tunnel facilities. The media for comparison were the aerodynamic slope values plotted as a function of Mach number for the different facilities. The slopes were computed using the SADSAC system and have been reduced relative to a common reference system. Data used for the comparison were selected based on a common baseline configuration. Identical configurations were available in all cases except MSFC 551 where an off-baseline vertical tail was tested. Some of the factors considered in comparing the various data were balance operating ranges and sensitivities, Reynolds number differences, scaling effects and control deflection accuracies.
An experimental investigation was conducted in an 11- by 11-foot wind tunnel to determine the aerodynamic characteristics of an oblique high aspect ratio wing in combination with a high fineness-ratio Sears-Haack body. Longitudinal and lateral-directional stability data were obtained at wing yaw angles from 0 deg to 60 deg over a test Mach number range from 0.6 to 1.4 for angles of attack between minus 6 deg and 9 deg. The effects of changes in Reynolds number, dihedral, and trailing-edge angle were studied along with the effects of a roughness strip on the upper and lower surfaces of the wing. Flow-visualization studies were made to determine the nature of the flow on the wing surfaces.
Description of a practical procedure for computing the wing leading-edge thrust distribution by the finite element method. When incorporated into a wing-body aerodynamic computer program, the technique is capable of predicting (at subsonic and supersonic speeds) the leading-edge thrust distribution (and therefore, the lateral-directional stability derivatives due to roll) and the nonlinear aerodynamic characteristics of low aspect-ratio wings with leading edge separation due to the application of suction technology.
Experimental aerodynamic investigations were conducted in the NASA/Ames 3.5-Foot Hypersonic wind Tunnel during the interim April 9-18, 1973 on a 0.015-scale model of the Rockwell International Space Shuttle Orbiter, configuration 2A. Six component aerodynamic force and moment data were recorded over an angle of attack range from -3 deg to 42 deg at 0 deg angle of sideslip and from -10 deg to 10 deg sideslip at 0 deg and 45 deg constant angle of attack. Test Mach numbers were 5.27 and 7.32 at unit Reynolds number of 2.5 million per foot. Various elevon, rudder, speedbrake, and body flap deflections were tested to determine longitudinal and lateral-directional stability characteristics and to establish trim capability.
The experimental longitudinal and lateral-directional stability characteristics of a Langley conceptual space shuttle orbiter design have been obtained for a series of inboard planform fillets in a unitary plan wind tunnel. Fillet sweep angles up to 78 deg were investigated while holding the spanwise intersection of the fillet and wing constant. The data were obtained at Mach numbers of 2.36 to 4.63 and at Reynolds numbers (depending on Mach number) of 1.5 million to 2.5 million per foot. The angle of attack was varied from about minus 2 deg to 44 deg at 0 deg and 3 deg of sideslip.
Data obtained from a wind tunnel test of a 0.015-scale 140A/B configuration SSV orbiter model are presented. This test was conducted with runs at Mach numbers of 2.5, 3.9, and 4.6 for a constant Reynolds number of 2.5 x 1,000,000/foot. Only one model configuration, the complete 140A/B orbiter vehicle, was investigated; various control-surface settings were run through angles-of-attack from -4 to +42 degrees at 0 and +3 degrees of yaw and through angles-of-sideslip from -4 to +6 degrees at 0, +10, +20, and +30 degrees pitch. The purpose of this test was to establish and verify longitudinal and lateral-directional stability and control characteristics for the updated SSV configuration.
An experimental investigation was conducted in a 9- by 7-foot supersonic wind tunnel to determine the effect of plume-induced flow separation and aspiration effects due to operation of both the orbiter and the solid rocket motors on a 0.019-scale model of the launch configuration of the space shuttle vehicle. Longitudinal and lateral-directional stability data were obtained at Mach numbers of 1.6, 2.0, and 2.2 with and without the engines operating. The plumes exiting from the engines were simulated by a cold gas jet supplied by an auxiliary 200 atmosphere air supply system, and by solid body plume simulators. Comparisons of the aerodynamic effects produced by these two simulation procedures are presented. The data indicate that the parameters most significantly affected by the jet plumes are the pitching moment, the elevon control effectiveness, the axial force, and the orbiter wing loads.
Experimental aerodynamic investigations were conducted in a 3.5-foot hypersonic wind tunnel. The model used for this test was a 0.010-scale of the Configuration 2 Space Shuttle Orbiter and the External Tank. Six-component aerodynamic force and moment data were recorded over an angle of attack range from -8 deg to +30 deg at 0 deg and 5 deg angles of sideslip. Data was also recorded during beta sweeps of -8 deg to +10 deg at angles of attack of -10 deg, 0 deg, and 30 deg. All testing was done at Mach 7.3. Various elevon, rudder and orbiter to external tank attaching structures and fairings were tested to determine longitudinal and lateral-directional stability characteristics. Non-metric exhaust plumes were installed during a portion of the testing to determine the effects of the main propulsion system rocket plumes.
The effect of plume-induced flow separation and aspiration effects due to operation of both orbiter and the solid rocket motors on a 0.019-scale model of the launch configuration of the Space Shuttle Vehicle is determined. Longitudinal and lateral-directional stability data were obtained at Mach numbers of 1.6, 2.0, and 2.2 with and without the engines operating. The plumes exiting from the engines were simulated by a cold-gas jet supplied by an auxiliary 200-atm air supply system and solid-body plume simulators. The aerodynamic effects produced by these two simulation procedures are compared. The parameters most significantly affected by the jet plumes are pitching moment, elevon control effectiveness, axial force, and orbiter wing loads. The solid rocket motor (SRM) plumes have the largest effect on the aerodynamic characteristics. The effect of the orbiter plumes in combination with the SRM plumes is also significant. Variations in the nozzle design parameters and configuration changes can reduce the jet plume-induced aerodynamic effects.
Longitudinal and lateral-directional stability characteristics of the 139-B orbiter (model 32-0) were obtained in a continuous flow hypersonic tunnel at Mach 10.3. Tests were made at Reynolds numbers of 1.04 million and 2.17 million (based on body length) over an angle of attack range of 12 deg to 36 deg at sideslip angles of 0 deg and minus 5 deg. Data were obtained at three elevon/body flap settings.
The longitudinal and summary lateral-directional stability characteristics have been obtained for a variety of irregular planform wings applied to a conceptual space shuttle orbiter. Three basic wing planforms with leading-edge sweep angles of 53.2 deg, 46.8 deg, and 35 deg were studied in conjunction with a series of inboard planform fillets with sweep angles up to 78 deg. The spanwise intersection point of the fillets and the basic wings was held constant. The data were obtained in the Langley 22-inch helium tunnel at a Mach number of 20.3 and a Reynolds number of 2.10 million based on model length. Model angle-of-attack range was from 0 deg to 54 deg at sideslip angles of 0 deg and minus 3.8 deg. Also included are results of a flow-visualization study consisting of electron-beam-illuminated flow and surface oil-flow patterns.
Wind tunnel tests were conducted of the NASA/Rockwell 0.015 scale configuration 4 mated space shuttle vehicle. Data were obtained for a range of Mach numbers from 1.60 to 4.63 and angles of attack from minus 10 degrees to plus 10 degrees. A complete model build-up was performed. Longitudinal and lateral directional stability and control data were obtained for the tank alone, tank plus solid rocket boosters, and mated configuration of tank plus orbiter plus solid rocket boosters. Single component rudder hinge moment data were obtained at rudder deflections of zero degrees and minus 20 degrees for each Mach number tested.
Wind tunnel tests were conducted to obtain aerodynamic force data for Mach numbers from 0.60 to 1.20. Data were obtained for an alpha range of -10 deg to +10 deg (beta = 0 deg beta = 5 deg) and beta range of -10 deg to +10 deg (alpha = 0 deg). Longitudinal and lateral-directional stability and control data were obtained for tank alone, tank plus SRB's, tank plus Orbiter, and mated configuration of tank + Orbiter + SRB's. Also, single-component rudder hinge moment data were obtained at rudder deflections of 0 and -20 deg for each Mach number tested. Plots of aerodynamic coefficients vs. Mach number are presented, using data from both test IA41 and tests LRC-UPWT-1056, 1073 (IA42A/B) for Mach numbers of 1.60 to 4.63. The model tested in IA42A/B was the same model as tested in IA41.