3,246 research outputs found
Orbiter Entry Heating Lessons Learned from Development Flight Test Program
The Space Shuttle orbiter's thermal protection system (TPS), designed mainly on the basis of wind tunnel test data, has successfully completed its design, development, and flight test program. The flight test data provide an exceptional opportunity to evaluate the use of wind tunnel test data for the design of TPS for reentry vehicles. Comparisons of flight test data against wind tunnel data used to design the orbiter's TPS were developed. These flight data, though still in the preliminary analysis phases, generally support the use of wind tunnel test data in the design of TPS for hypersonic reentry vehicles
Space shuttle wing leading edge heating environment prediction derived from development flight data
An analytical program is in progress at Rockwell International to revise wing leading edge heating predictions in order to improve correlation with STS-1 to -5 flight radiometer data. This paper discusses the methods that have been used to improve agreement between prediction and flight and summarizes the aerodynamic correlations which, when updated, will be used to analyze future orbiter missions
Continuity of object tracking
2022 Spring.Includes bibliographical references.The demand for object tracking (OT) applications has been increasing for the past few decades in many areas of interest: security, surveillance, intelligence gathering, and reconnaissance. Lately, newly-defined requirements for unmanned vehicles have enhanced the interest in OT. Advancements in machine learning, data analytics, and deep learning have facilitated the recognition and tracking of objects of interest; however, continuous tracking is currently a problem of interest to many research projects. This dissertation presents a system implementing a means to continuously track an object and predict its trajectory based on its previous pathway, even when the object is partially or fully concealed for a period of time. The system is divided into two phases: The first phase exploits a single fixed camera system and the second phase is composed of a mesh of multiple fixed cameras. The first phase system is composed of six main subsystems: Image Processing, Detection Algorithm, Image Subtractor, Image Tracking, Tracking Predictor, and the Feedback Analyzer. The second phase of the system adds two main subsystems: Coordination Manager and Camera Controller Manager. Combined, these systems allow for reasonable object continuity in the face of object concealment
Computational wing optimization and comparisons with experiment for a semi-span wing model
A computational wing optimization procedure was developed and verified by an experimental investigation of a semi-span variable camber wing model in the NASA Ames Research Center 14 foot transonic wind tunnel. The Bailey-Ballhaus transonic potential flow analysis and Woodward-Carmichael linear theory codes were linked to Vanderplaats constrained minimization routine to optimize model configurations at several subsonic and transonic design points. The 35 deg swept wing is characterized by multi-segmented leading and trailing edge flaps whose hinge lines are swept relative to the leading and trailing edges of the wing. By varying deflection angles of the flap segments, camber and twist distribution can be optimized for different design conditions. Results indicate that numerical optimization can be both an effective and efficient design tool. The optimized configurations had as good or better lift to drag ratios at the design points as the best designs previously tested during an extensive parametric study
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Remote detection and location of explosive volcanism in Alaska with the EarthScope Transportable Array
A Phase I Cultural Resource Survey for the Proposed Six Mile Boat Ramp Expansion Project (Texas Antiquities Permit #9155)
Cultural Resource Analysts, Inc., personnel completed a records review and cultural resource survey for the proposed expansion of the existing Six Mile Boat Ramp in Sabine County, Texas. This work was performed to assist the Sabine River Authority of Texas in complying with Section 106 of the National Historic Preservation Act of 1966 (Public Law 89-665, 16 U.S.C. 470h-2) as an applicant for a Section 404 Clean Water Act Permit from the US Army Corps of Engineers, and the provisions of the Texas Administrative Code regarding archaeological resources on public lands. The Texas Administrative Code requires review of projects on state-owned lands by the Texas Antiquities Commission. The Sabine River Authority of Texas is considered a political subdivision of the State of Texas, and therefore it has a responsibility to provide the Texas Antiquities Commission an opportunity to review projects that may affect potential or designated archaeological sites. This project was performed under Texas Antiquities Permit (No. 9155). All work was performed pursuant to the guidelines published by the Council of Texas Archeologists and adopted by the Texas Historical Commission, and this report was prepared following the short report format in the Guidelines for Cultural Resource Management Reports published by the Council of Texas Archeologists.
The current proposed project includes the expansion of the Six Mile Boat Ramp on the Toledo Bend Reservoir in Sabine County, Texas. The proposed development includes the addition of a handicap-accessible floating boat ramp, the clearing of approximately 0.4 ha (1.0 acre) of trees, the construction of a parking area, the addition of a vault toilet, the addition of two tables on concrete platforms, and the clearing of trees along the shoreline to provide an enhanced scenic view. In order to provide some flexibility in siting these facilities, the direct and visual areas of potential effect for this project were within a polygon adhering on its southern and western boundaries to the property line, and roughly buffered to the north and east by the existing shoreline of the Toledo Bend Reservoir. It is estimated that the area of potential effect for this project measures 1.2 ha (3.0 acres), of which approximately 0.9 ha (2.2 acres) could be surveyed, excluding paved surfaces.
The records review for this project was conducted on October 18, 2019, prior to the commencement of the field survey, to identify cultural resources or cultural resource investigations previously documented within the area. This file search utilized online files maintained by the Texas Archaeological Research Laboratory at the University of Texas. Additionally, historic maps were examined to identify the locations of any potential historic archaeological sites. The records review indicated that one previously documented site, 41SB58, was located within approximately 50 m (164 ft) to the north of the proposed project area. Additionally, one historic structure was depicted within the project area on historic mapping.
Fieldwork was conducted on November 19, 2019, and was completed in 11.5 person hours. The project area was systematically investigated by pedestrian survey and screened shovel tests spaced at a 30 m (98 ft) interval on pedestrian transects spaced at 30 m. The fieldwork for this project resulted in one newly recorded isolated find that is not eligible for designation as a Texas State Archeological Landmark or for listing in the National Register of Historic Places. Based on the findings of this work, it is recommended that the project area be considered cleared from a cultural resource perspective
New approaches for estimating risk from exposure to diethylstilbestrol.
A subgroup from a National Institute of Environmental Health Sciences, workshop concerned with characterizing the effects of endocrine disruptors on human health at environmental exposure levels considered the question, If diethylstilbestrol (DES) were introduced into the market for human use today and likely to result in low-dose exposure of the human fetus, what would be required to assess risk? On the basis of an analysis of the quality of data on human DES exposure, the critical times and doses for inducing genital tract malformations and cancer must be determined. This would be facilitated through analysis of the ontogeny of estrogen receptor expression in the developing human genital tract. Models of low-dose estrogenic effects will have to be developed for human and rodent genital tract development. Mouse models offer many advantages over other potential animal models because of the wealth of the earlier literature, the availability of sensitive end points, the availability of mutant lines, and the possibility of generating genetically engineered model systems. Through multidisciplinary approaches, it should be possible to elucidate the cellular and molecular mechanisms of endocrine disruption elicited by estrogens during development and facilitate an assessment of risk to humans
Issues Associated with a Hypersonic Maglev Sled
Magnetic levitation has been explored for application from motors to transportation. All of these applications have been at velocities where the physics of the air or operating fluids are fairly well known. Application of Maglev to hypersonic velocities (Mach greater than 5) presents many opportunities, but also issues that require understanding and resolution. Use of Maglev to upgrade the High Speed Test Track at Holloman Air Force Base in Alamogordo New Mexico is an actual hypersonic application that provides the opportunity to improve test capabilities. However, there are several design issues that require investigation. This paper presents an overview of the application of Maglev to the test track and the issues associated with developing a hypersonic Maglev sled. The focus of this paper is to address the issues with the Maglev sled design, rather than the issues with the development of superconducting magnets of the sled system
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