Spacecraft design project: Low Earth orbit communications satellite

This is the final product of the spacecraft design project completed to fulfill the academic requirements of the Spacecraft Design and Integration 2 course (AE-4871) taught at the U.S. Naval Postgraduate School. The Spacecraft Design and Integration 2 course is intended to provide students detailed design experience in selection and design of both satellite system and subsystem components, and their location and integration into a final spacecraft configuration. The design team pursued a design to support a Low Earth Orbiting (LEO) communications system (GLOBALSTAR) currently under development by the Loral Cellular Systems Corporation. Each of the 14 team members was assigned both primary and secondary duties in program management or system design. Hardware selection, spacecraft component design, analysis, and integration were accomplished within the constraints imposed by the 11 week academic schedule and the available design facilities

Effects of Surface Application of Dairy Manure on the Infiltration Rate and Quality of Surface Runoff

Dairy manure was surface spread on 12 ft x 12 ft plots on an established fescue pasture in the summer and fall of 1981 and 1982. The soil was a Maury silt loam. A simulated rainfall was applied to plots to test the effects of nitrogen loading rate (75, 150, and 300 #N/acre) time delay between manure application and the simulated rainfall events (0, 3, 6, 24, 48, 96 hours and a 120 hour test repeated on 0 hr plot with 300 #N/acre), and type manure (semi-solid - 1981 and liquid - 1982) on the concentrations of pollutants in the surface runoff. The pollutants measured were COD, TSS, FSS, VSS, TS, FS, VS, N03, NH4 , N, P, and K. The simulated rainfall rates were 3.42 in/hr for 1981 and 4.02 in hr for 1982. The average field infiltration rate for the non-manured test plots were 3.40 in/hr in 1981 and 4.42 in/hr in 1982. The infiltration rates of the manured plots were reduced by 5.8 to 15 percent for semi-solid manure and 23 to 31 percent for liquid manure for zero hour time delay plots. The infiltration rates increased to within 92 percent of the control plots after 120 hour time delay. The pollutant yields increased with nitrogen loading rate except for FSS yield which remained below the control plot yields. The NO3 yields was below the control plot except for 300 #N/acre plots. The reduction in pollutant yields with increased time delay was found to average 46 and 76 percent for the 24 and 48 hour time delays for semi-solid manure and 75 and 94 percent for liquid manure. The yields for TSS, FSS and VSS for liquid manured plots did not exceed the control plot yields until after the 48 hour time delay

Development of a Turbidity Prediction Methodology for Runoff-Erosion Models

Surface water bodies can be impaired by turbidity and excessive sediment loading due to urban development, construction activities, and agricultural practices. Turbidity has been considered as a proxy for evaluating water quality, aquatic habitat, and aesthetic impairments in surface waters. The US Environment Protection Agency (USEPA) has listed turbidity and sediment as major pollutants for construction site effluent. Recently proposed USEPA regulations for construction site runoff led to increased interest in methods to predict turbidity in runoff based on parameters that are more commonly predicted in runoff- erosion models. In this study, a turbidity prediction methodology that can be easily incorporated into existing runoff-erosion models has been developed using fractions of sand, silt, and clay plus suspended sediment concentration of eight parent soils from locations in Oklahoma and South Carolina, USA

Spacecraft Design Project Low Earth Orbit Communications Satellite

AE-4871 Advance Spacecraft DesignNASA-CR-192038This report is the final product of the spacecraft design project completed to fulfill the academic requirements of the Spacecraft Design and Integration II course (AE-4871) taught at the U.S. Naval Postgraduate School.NASA/Universities Space Research Association Advanced Design Progra