SCIENTIFIC AND TECHNICAL AEROSPACE REPORTS

A Biweekly Publication of the National Aeronautics and Space Administration
VOLUME 43, ISSUE 19 - SEPTEMBER 23, 2006

18 SPACECRAFT DESIGN, TESTING AND PERFORMANCE
Includes satellites; space platforms; space stations; spacecraft systems and components such as thermal and environmental controls; and spacecraft control and stability characteristics.

For life support systems see 54 Man/System Technology and Life Support.

For related information see also 05 Aircraft Design, Testing and Performance; 39 Structural Mechanics; and 16 Space Transportation and Safety.

20050210092 NASA Glenn Research Center, Cleveland, OH, USA

Advanced Vibration Analysis Tools and New Strategies for Robust Design of Turbine Engine Rotors

Min, James B.; Research and Technology 2001; March 2002; 3 pp.; In English; No Copyright; Avail: CASI; A01, Hardcopy

The adverse effects of small, random structural irregularities among the blades, called mistuning, can result in blade forced-response amplitudes and stresses that are much larger than those predicted for a perfectly tuned rotor. Manufacturing tolerances, deviations in material properties, or nonuniform operational wear causes mistuning; therefore, mistuning is unavoidable. Furthermore, even a small mistuning can have a dramatic effect on the vibratory behavior of a rotor because it can lead to spatial localization of the vibration energy (see the following photographs). As a result, certain blades may experience forced response amplitudes and stresses that are substantially larger than those predicted by an analysis of the nominal (tuned) design. Unfortunately, these random uncertainties in blade properties, and the immense computational effort involved in obtaining statistically reliable design data, combine to make this aspect of rotor design cumbersome. Derived from text

Dynamic Structural Analysis; Vibration; Turbine Engines; Rotors

20050212037 NASA Langley Research Center, Hampton, VA, USA

X-43D Conceptual Design and Feasibility Study

Johnson, Donald B.; Robinson, Jeffrey S.; [2005]; 12 pp.; In English; 13th AIAA/CIRA International Space Planes and Hypersonic Systems Technologies Conference, 16-20 May 2005, Capua, Italy Contract(s)/Grant(s): 23-065-50-SL Report No.(s): AIAA Paper 2005-3416; Copyright; Avail: CASI; A03, Hardcopy

NASA s Next Generation Launch Technology (NGLT) Program, in conjunction with the office of the Director of Defense Research and Engineering (DDR&E), developed an integrated hypersonic technology demonstration roadmap. This roadmap is an integral part of the National Aerospace Initiative (NAI), a multi-year, multi-agency cooperative effort to invest in and develop, among other things, hypersonic technologies. This roadmap contains key ground and flight demonstrations required along the path to developing a reusable hypersonic space access system. One of the key flight demonstrations required for systems that will operate in the high Mach number regime is the X-43D. As currently conceived, the X-43D is a Mach 15 flight test vehicle that incorporates a hydrogen-fueled scramjet engine. The purpose of the X-43D is to gather high Mach number flight environment and engine operability information which is difficult, if not impossible, to gather on the ground. During 2003, the NGLT Future Hypersonic Flight Demonstration Office initiated a feasibility study on the X-43D. The objective of the study was to develop a baseline conceptual design, assess its performance, and identify the key technical issues. The study also produced a baseline program plan, schedule, and cost, along with a list of key programmatic risks. Author

Flight Test Vehicles; Hypersonic Flight; Mach Number; Feasibility; Project Planning; Flight Tests

20050212421 NASA Goddard Space Flight Center, Greenbelt, MD, USA

Nonlinear Attitude Filtering Methods

Markley, F. Landis; Crassidis, John L.; Cheng, Yang; July 14, 2005; 32 pp.; In English; AIAA Guidance, Navigation and Control Conference, 15-18 Aug. 2005, San Francisco, CA, USA; Copyright; Avail: CASI; A03, Hardcopy

This paper provides a survey of modern nonlinear filtering methods for attitude estimation. Early applications relied mostly on the extended Kalman filter for attitude estimation. Since these applications, several new approaches have been developed that have proven to be superior to the extended Kalman filter. Several of these approaches maintain the basic structure of the extended Kalman filter, but employ various modifications in order to provide better convergence or improve other performance characteristics. Examples of such approaches include: filter QUEST, extended QUEST, the super-iterated extended Kalman filter, the interlaced extended Kalman filter, and the second-order Kalman filter. Filters that propagate and update a discrete set of sigma points rather than using linearized equations for the mean and covariance are also reviewed. A two-step approach is discussed with a first-step state that linearizes the measurement model and an iterative second step to recover the desired attitude states. These approaches are all based on the Gaussian assumption that the probability density function is adequately specified by its mean and covariance. Other approaches that do not require this assumption are reviewed, including particle filters and a Bayesian filter based on a non-Gaussian, finite-parameter probability density function on SO(3). Finally, the predictive filter, nonlinear observers and adaptive approaches are shown. The strengths and weaknesses of the various approaches are discussed. Author

Attitude (Inclination); Kalman Filters; Nonlinear Filters; Satellite Orientation

20050214734 NASA Glenn Research Center, Cleveland, OH, USA

Life-Prediction Parameters of Sapphire Determined for the Design of a Space Station Combustion Facility Window

Salem, Jonathan A.; Research and Technology 2002; March 2003; 2 pp.; In English; No Copyright; Avail: CASI; A01, Hardcopy

To characterize the stress corrosion parameters and predict the life of a sapphire window being considered for use in the International Space Station’s Fluids and Combustion Facility, researchers at the NASA Glenn Research Center conducted stress corrosion tests, fracture toughness tests, and reliability analyses, as shown in the figures. Standardized test methods, developed and updated by the author under the auspices of American Society for Testing and Materials, were employed. One interesting finding is that sapphire exhibits a susceptibility to stress corrosion in water similar to that of glass. In addition to generating the stress corrosion parameters and fracture toughness data, closed-form expressions for the variances of the crack growth parameters were derived. The expressions allow confidence bands to be easily placed on life predictions of ceramic components. Brittle materials such as sapphire and quartz are required for windows in a variety of applications such as the Fluids and Combustion Facility. To minimize the launch weight of such facilities, researchers must design the windows to be as lightweight as possible. The safe use of lightweight, brittle windows in structural applications is limited by two factors: low fracture toughness and slow crack growth, or stress corrosion. Stress corrosion of these and other optical materials can occur in relatively common environments, such as humid air. Access to the data has been requested by designers for use in the life prediction of a Northrop Grumman F16 instrument window and a Jet Propulsion Laboratory instrument window. One Space Act Agreement has been formed. Future work includes the measurement of the life of subscale windows. Author

Sapphire; Combustion Chambers; Space Stations; Stress Corrosion

20050214832 NASA Kennedy Space Center, Cocoa Beach, FL, USA

Return to Flight Resource Reel 1 of 2

August 2005; In English; 1 hr., 1 min., 30 sec. playing time, in color, with sound; No Copyright; Avail: CASI; V04, Videotape-VHS; B04, Videotape-Beta

A video presentation detailing the tests performed on the Space Shuttle Discovery in preparation for its return to flight is shown. The tests include: 1) Reinforced Carbon-Carbon (RCC) Impact Test Article; 2) RCC Foam Impact Testing; 3) Thermal Protection System (TPS) Ice Impact Testing featuring Justin Kerr, Project Engineer; 4) Wing Leading Edge Wireless Sensors featuring Karl Kiefer, President and CEO of Invocon, and Kevin Champaigne of Invocon; 5) TPS Repair Testing KC-135 Zero-G Environment featuring Soichi Noguchi, Mission Specialist; 6) TPS Extravehicular Activity Tool Demonstration; 7) TPS Repair Testing Vacuum Glove box; 8) TPS Repair Testing Human Thermal Vacuum Chamber; 9) TPS Reentry Testing Atmospheric Reentry Materials and Structures Evaluation Facility; 10) TPS Alternative Repair Concept; 11) Lora Bailey Lead Engineer for EVATools; 12) Reinforced Carbon-CarbonATK Thiokol Plug Repair Animation; 13) 3-Percent Model Build-Up; and 14) Wind Tunnel Testing RCC Aging Research Ballistic Testing. CASI

Discovery (Orbiter); Space Transportation System; NASA Space Programs; Spacecraft Maintenance

20050214845 NASA Kennedy Space Center, Cocoa Beach, FL, USA

Return to Flight Resource Reel 2 of 2

August 2005; In English; 51 min., 30 sec. playing time, in color, with sound; No Copyright; Avail: CASI; V03, Videotape-VHS; B03, Videotape-Beta

A continuation of the tests performed on the Space Shuttle Discovery in preparation for its return to flight is presented. The tests include: 1) Shuttle Robot Arm Recertification; 2) Michael Hiltz Systems Group Leader; 3) Orbiter Boom Fabrication; 4) Orbiter Boom Final Development; 5) Gary Searle Manager of Orbiter Boom Sensor System (OBSS) Manufacturing and Assembly; 6) Orbiter Boom Qualification Unit; 7) STS-114 Crew Inspects Orbiter Boom at Kennedy Space Center; 8) Orbiter Boom Inspection of Thermal Protection System Animation; 9) External Tank Bipod Redesign; 10) External Tank Flange Redesign; 11) External Tank Bellows Redesign; 12) Shuttle Main Engine Testing and Delivery to Kennedy Space Center; 13) Ronnie Rigney Project Manager Space Shuttle Main Engine Program Office; 14) Gene Goldmman NASA Project Manager Space Shuttle Main Engine Project; 15) Mike Cosgrove Boeing-Rocketdyne Flow Manager; 16) Shuttle Rocket Booster Build-Up; 17) Ascent Imagery Improvements; and 18) STS-114 Flight Control Team and Mission Management Team. CASI

Discovery (Orbiter); NASA Space Programs; Spacecraft Maintenance; Space Transportation System

Source: NASA.