Search NASA⌕ Search

SEARCH · Search NASA

Results for “shuttle effects”

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.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 271 records · Page 15

The Development of a Stochastic Model of the Atmosphere Between 30 and 90 Km to Be Used in Determining the Effect of Atmospheric Variability on Space Shuttle Entry Parameters

A stochasitc model of the atmosphere between 30 and 90 km was developed for use in Monte Carlo space shuttle entry studies. The model is actually a family of models, one for each latitude-season category as defined in the 1966 U.S. Standard Atmosphere Supplements. Each latitude-season model generates a pseudo-random temperature profile whose mean is the appropriate temperature profile from the Standard Atmosphere Supplements. The standard deviation of temperature at each altitude for a given latitude-season model was estimated from sounding-rocket data. Departures from the mean temperature at each altitude were produced by assuming a linear regression of temperature on the solar heating rate of ozone. A profile of random ozone concentrations was first generated using an auxiliary stochastic ozone model, also developed as part of this study, and then solar heating rates were computed for the random ozone concentrations.

Campbell, J. W.↗

Space shuttle vehicle ferry configuration afterbody fairing effects on 140A/B orbiter aerodynamic characteristics using an .0405 scale model orbiter (43-0) in the Rockwell International 7.75 x 11 ft low speed wind tunnel (OA123)

The primary test objectives were to define ferry configuration afterbody fairing effects on orbiter stability and control characteristics and to substantiate wind tunnel results. Parametric variations consisted entirely of testing different afterbody fairing contours in an effort to improve both the orbiter drag levels and lateral-directional control characteristics. The three afterbody contours that were tested consisted of the Boeing TC3 beavertail, the new Rockwell-Boeing TC4 fairing, and a modification of an existing short bumblebee fairing redesignated TC6.

Mennell, R. C.↗

Effects of modifications to the space shuttle entry guidance and control systems

A nonlinear six degree of freedom entry simulation study was conducted to identify space shuttle guidance and control system software modifications which reduce the control system sensitivity to the guidance system sampling frequency. Several modifications which eliminated the control system sensitivity and associated control limit cycling were examined. The result of the modifications was a reduction in required reaction control system fuel.

Powell, R. W.↗

Flying qualities of an aircraft with strong lateral-directional coupling

Flying qualities of aircraft with strong lateral-directional coupling may be unsatisfactory without command and stability augmentation. Although sensitivity to stability derivative variation may be decreased by such a flight control system (FCS), deficiencies associated with control derivative uncertainty may persist or worsen. This is especially true in systems with necessarily high gains, e.g., the Space Shuttle Entry FCS. Effects of stability/control derivative variations on the flying qualities of the Space Shuttle (with and without FCS) have been investigated, and the unaugmented Space Shuttle has been simulated in flight using Princeton's Variable-Response Research Aircraft (VRA).

Stengel, R. F.↗

Lightning Protection System for Space Shuttle

The suitability and cost effectiveness of using a lightning mast for the shuttle service and access tower (SSAT) similar to the type used for the Apollo Soyuz Test Project (ASTP) mobile launcher (ML) was evaluated. Topics covered include: (1) ASTP launch damage to mast, mast supports, grounded overhead wires, and the instrumentation system; (2) modifications required to permit reusing the ASTP mast on the SSAT; (3) comparative costing factors per launch over a 10 year period in repetitive maintenance and refurbishment of the existing and modified masts, mast supports, grounded overhead wires, and ground instrumentation required to sustain mechanical and electrical integrity of the masts; (4) effects of blast testing samples of the ASTP ML type mast (corrosion and electrical flashover); (5) comparison of damages from ASTP launch and from blast testing.

Source record↗

Effects of wing/elevon gap sealing flapper doors on orbiter elevon effectiveness of model 16-0 in the NAAL 7.75 by 11 foot continuous flow wind tunnel (OA119A)

Space shuttle orbiter elevon effectiveness was measured with the 6 inch elevon/elevon and elevon/fuselage gaps and various configurations of wing/elevon upper hingeline gap sealing flapper doors. The elevon configuration parametric variations consisted of sealing the lower hingeline to prevent flow-through and testing a long chord flapper door, a short chord flapper door, no flapper door (elevon/wing gap upper hingeline completely open), and a completely sealed elevon at elevon deflections from +20 deg to -40 deg. Preliminary data analysis indicates loss of elevon effectiveness at deflections more negative than -20 deg, and little or no effect of flapper door configuration on elevon effectiveness. Flow visualization photographs taken at alpha = 15 deg for two flapper door configurations substantiated the force data results. Aerodynamic force and moment data were measured in the body axis by a 2.5 inch task type internal strain gage balance. The model was sting supported through the base region with a nominal angle of attack range of -10 deg less than or equal to alpha less than or equal to 24 deg at a model angle of sideslip of Beta equal to 0 deg.

Mennell, R.↗

Manned maneuvering unit mission definition study. Volume 3: MMU ancillary support equipment and attachment concepts

An analysis of Manned Maneuvering Units (MMU) ancillary support equipment and attachment concepts is presented. The major objectives of the study are defined as: (1) identifying MMU applications which would supplement space shuttle safety and effectiveness, (2) to define general MMU performance and control requirements to satisfy candidate shuttle applications, (3) to develop concepts for attaching MMUs to various worksites and equipment, and (4) to identify requirements and develop concepts for MMU ancillary equipment.

Source record↗

The effect of sensor spacing on wind measurements at the Shuttle Landing Facility

This document presents results of a field study of the effect of sensor spacing on the validity of wind measurements at the Space Shuttle landing Facility (SLF). Standard measurements are made at one second intervals from 30 foot (9.1m) towers located 500 feet (152m) from the SLF centerline. The centerline winds are not exactly the same as those measured by the towers. This study quantifies the differences as a function of statistics of the observed winds and distance between the measurements and points of interest. The field program used logarithmically spaced portable wind towers to measure wind speed and direction over a range of conditions. Correlations, spectra, moments, and structure functions were computed. A universal normalization for structure functions was devised. The normalized structure functions increase as the 2/3 power of separation distance until an asymptotic value is approached. This occurs at spacings of several hundred feet (about 100m). At larger spacings, the structure functions are bounded by the asymptote. This enables quantitative estimates of the expected differences between the winds at the measurement point and the points of interest to be made from the measured wind statistics. A procedure is provided for making these estimates.

Merceret, Francis J.↗

The influence of the launch site operational environment on Space Shuttle scientific payloads

The effects of prelaunch assembly, testing, and integration activities on the scientific payload at the KSC are examined. The functions of the Shuttle and payload organizations of the KSC are discussed. The processing of the various types of pyaloads, and the amount of access to the payload during processing and after landing are described. The KSC facility contains: an Operations and Checkout Building, a Vertical Processing Facility, Cargo Integration and Test Equipment, an Orbiter Processing Facility, a Payload Changeout Room, payload transportation equipment, and Shuttle launch pads.

Schuiling, Roelof L.↗

Comparison of pilot effective time delay for cockpit controllers used on space shuttle and conventional aircraft

A study was conducted at the Dryden Flight Research Facility of NASA Ames Research Center (Ames-Dryden) to compare pilot effective time delay for the space shuttle rotational hand controller with that for conventional stick controllers. The space shuttle controller has three degrees of freedom and nonlinear gearing. The conventional stick has two degrees of freedom and linear gearing. Two spring constants were used, allowing the conventional stick to be evaluated in both a light and a heavy configuration. Pilot effective time delay was obtained separately for pitch and roll through first-order, closed-loop, compensatory tracking tasks. The tasks were implemented through the space shuttle cockpit simulator and a critical task tester device. A total of 900 data runs were made using four test pilots and one nonpilot (engineer) for two system delays in pitch and roll modes. Results showed that the heavier conventional control stick had the lowest pilot effective time delays. The light conventional control stick had pilot effective time delays similar to those of the shuttle controller. All configurations showed an increase in pilot effective time delay with an increase in total system delay.

Privoznik, C. M.↗

Space shuttle: Static aerodynamic characteristics characteristics and control effectiveness for McDonnell-Douglas orbiter configuration for Mach number range of 0.4 to 5.0

An experimental aerodynamic wind tunnel investigation was conducted employing a 0.00325 scale model of the McDonnell-Douglas space shuttle orbiter configuration. This investigation was conducted in the NASA/Marshall Space Flight Center 14- by 14- inch trisonic wind tunnel. The investigation was to determine the aerodynamic characteristics of the orbiter over the Mach number range of 0.4 to 5.0, an angle of attack variation from -4 degrees to 50 degrees, and -6 degrees to 9 degrees angle of sideslip. Control surface effectiveness was investigated for elevator, aileron, and rudder deflections.

Ellis, R. R.↗

Effect of Clouds on Optical Imaging of the Space Shuttle During the Ascent Phase: A Statistical Analysis Based on a 3D Model

Clouds are highly effective in obscuring optical images of the Space Shuttle taken during its ascent by ground-based and airborne tracking cameras. Because the imagery is used for quick-look and post-flight engineering analysis, the Columbia Accident Investigation Board (CAIB) recommended the return-to-flight effort include an upgrade of the imaging system to enable it to obtain at least three useful views of the Shuttle from lift-off to at least solid rocket booster (SRB) separation (NASA 2003). The lifetimes of individual cloud elements capable of obscuring optical views of the Shuttle are typically 20 minutes or less. Therefore, accurately observing and forecasting cloud obscuration over an extended network of cameras poses an unprecedented challenge for the current state of observational and modeling techniques. In addition, even the best numerical simulations based on real observations will never reach "truth." In order to quantify the risk that clouds would obscure optical imagery of the Shuttle, a 3D model to calculate probabilistic risk was developed. The model was used to estimate the ability of a network of optical imaging cameras to obtain at least N simultaneous views of the Shuttle from lift-off to SRB separation in the presence of an idealized, randomized cloud field.

FROM↗

Space Shuttle utilization characteristics with special emphasis on payload design, economy of operation and effective space exploitation

The reusable manned Space Shuttle has made new and innovative payload planning a reality and opened the door to a variety of payload concepts formerly unavailable in routine space operations. In order to define the payload characteristics and program strategies, current Shuttle-oriented programs are presented: NASA's Space Telescope, the Long Duration Exposure Facility, the West German Shuttle Pallet Satellite, and the Goddard Space Flight Center's Multimission Modular Spacecraft. Commonality of spacecraft design and adaptation for specific mission roles minimizes payload program development and STS integration costs. Commonality of airborne support equipment assures the possibility of multiple program space operations with the Shuttle. On-orbit maintenance and repair was suggested for the module and system levels. Program savings from 13 to over 50% were found obtainable by the Shuttle over expendable launch systems, and savings from 17 to 45% were achievable by introducing reuse into the Shuttle-oriented programs.

Turner, D. N.↗

Modeling the Nonlinear, Strain Rate Dependent Deformation of Shuttle Leading Edge Materials with Hydrostatic Stress Effects Included

An analysis method based on a deformation (as opposed to damage) approach has been developed to model the strain rate dependent, nonlinear deformation of woven ceramic matrix composites, such as the Reinforced Carbon Carbon (RCC) material used on the leading edges of the Space Shuttle. In the developed model, the differences in the tension and compression deformation behaviors have also been accounted for. State variable viscoplastic equations originally developed for metals have been modified to analyze the ceramic matrix composites. To account for the tension/compression asymmetry in the material, the effective stress and effective inelastic strain definitions have been modified. The equations have also been modified to account for the fact that in an orthotropic composite the in-plane shear response is independent of the stiffness in the normal directions. The developed equations have been implemented into LS-DYNA through the use of user defined subroutines (UMATs). Several sample qualitative calculations have been conducted, which demonstrate the ability of the model to qualitatively capture the features of the deformation response present in woven ceramic matrix composites.

Goldberg, Robert K.↗

Effects of surface roughness on the aerodynamic characteristics of the Space Shuttle Orbiter configuration

An investigation has been conducted to determine the effects of surface roughness on two Space Shuttle Orbiter models. The tests were conducted over a Mach number range from 0.2 to 6.0 in the Langley Low Turbulance Pressure Tunnel, 8-foot Transonic Pressure Tunnel, Unitary Plan Wind Tunnel, 20-Inch Mach 6 Tunnel, and the Vought High Speed Tunnel. Analytical estimates of the degradation of the subsonic performance resulting from the roughness were made and are presented. The investigation also included tests to explore the possibility of asymmetric flow separation or attachment over the wings during transition from high to low angles of attack that might cause roll divergence.

Ware, G. M.↗

Debris/Ice/TPS Assessment and Integrated Photographic Analysis for Shuttle Mission STS-49

A debris/ice/Thermal Protection System (TPS) assessment and integrated photographic analysis was conducted for Shuttle Mission STS-49. Debris inspections of the flight elements and launch pad were performed before and after launch. Ice/frost conditions on the External Tank were assessed by the use of computer programs, nomographs, and infrared scanner data during cryogenic loading of the vehicle followed by on-pad visual inspection. High speed photography was analyzed after launch to identify ice/debris sources and evaluate potential vehicle damage and/or in-flight anomalies. Debris/ice/TPS conditions and integrated photographic analysis of Shuttle Mission STS-49, and the resulting effect on the Space Shuttle Program are discussed.

Katnik, Gregory N.↗