Performance capability of laser-powered launch vehicles using vertical ascent trajectories

The use of a ground-based high-power laser source to power a vertically launched rocket vehicle is investigated. By using a vertical ascent trajectory, only a single laser source is required. The vertical ascent mode is not applicable to earth orbit destinations but is applicable to missions beyond earth escape. Performance and trajectory characteristics are examined for vertical trajectories to earth escape and solar escape (which may be of interest in the future for radioactive waste disposal). Specific impulse values from 2000 to 5000 seconds are considered. With these values, a single-stage vehicle can deliver payloads to earth escape and beyond, but extremely high power sources (gigawatts) are required

Payload optimization of multistage launch vehicles

Payload optimization of multistage launch vehicle- generalized Bolza problem for maximal payload capability analysi

San Luis Obispo High School FFA Swine Barn Demolition and Enclosure Reconfiguration

The San Luis Obispo High School (SLOHS) FFA program required an upgrade to its deteriorating swine barn. This project came in three unique scopes of work: demolition of the existing barn, proper disposal of materials, and reconfiguration of the enclosure and water lines. This paper will cover specifically the reconfiguration of the enclosures and the redesign of the watering system. This phase of the project required skills in framing and plumbing, which our team had absorbed during specific construction management courses at Cal Poly. The reconfiguration included framing and securing a long span of fencing along the northern side of the project area, as well as tying together existing elements of the barn with newly added structures. Watering systems needed to be completely rerouted with newly added PVC to bring fresh water from the main water supply to each swine enclosure. Some challenges the team had to overcome include ensuring structural integrity and timely resolving water system leaks. The paper incorporates a lesson-learned section that highlights the importance of thorough planning, structural integrity, and adaptability in construction. Ultimately, the collaborative effort improved the safety and functionality of the enclosures, which met the needs of SLOHS\u27s FFA program

Evaluation of proposed Skylab and SSP soap products

Three personal hygiene cleansing agents and one laundry detergent (sodium dodecyl benzene sulfonate), which are all candidates for use on long-duration space missions, were evaluated in terms of dermatological effects on human subjects and effects on microbiological species. None of the four materials exhibited adverse dermatological effects from either skin patch tests of two weeks duration or a simulated Skylab personal hygiene regimen of up to four weeks duration. No significant alterations in skin microflora during the use regimen were found. None of the four materials were found to serve as microbiological support media for the species tested, but a species of air-borne mold was observed to grow rapidly in a neutralized aqueous solution. None of the candidate agents was found to be strongly biocidal

LSS/propulsion interactions studies

Interactions between the LSS and the propulsion system are large, significant, interrelated, and complex. Issues and problems in interfacing include the effects on the structure from static, dynamic, and launch loads, control, thrust distribution, throttling, and the environment. Control interaction, the disposal of debris/obsolete spacecraft, and the constraints of launch to low Earth orbit must also be considered

DUKSUP: A Computer Program for High Thrust Launch Vehicle Trajectory Design and Optimization

From the late 1960's through 1997, the leadership of NASA's Intermediate and Large class unmanned expendable launch vehicle projects resided at the NASA Lewis (now Glenn) Research Center (LeRC). One of LeRC's primary responsibilities --- trajectory design and performance analysis --- was accomplished by an internally-developed analytic three dimensional computer program called DUKSUP. Because of its Calculus of Variations-based optimization routine, this code was generally more capable of finding optimal solutions than its contemporaries. A derivation of optimal control using the Calculus of Variations is summarized including transversality, intermediate, and final conditions. The two point boundary value problem is explained. A brief summary of the code's operation is provided, including iteration via the Newton-Raphson scheme and integration of variational and motion equations via a 4th order Runge-Kutta scheme. Main subroutines are discussed. The history of the LeRC trajectory design efforts in the early 1960's is explained within the context of supporting the Centaur upper stage program. How the code was constructed based on the operation of the Atlas/Centaur launch vehicle, the limits of the computers of that era, the limits of the computer programming languages, and the missions it supported are discussed. The vehicles DUKSUP supported (Atlas/Centaur, Titan/Centaur, and Shuttle/Centaur) are briefly described. The types of missions, including Earth orbital and interplanetary, are described. The roles of flight constraints and their impact on launch operations are detailed (such as jettisoning hardware on heating, Range Safety, ground station tracking, and elliptical parking orbits). The computer main frames on which the code was hosted are described. The applications of the code are detailed, including independent check of contractor analysis, benchmarking, leading edge analysis, and vehicle performance improvement assessments. Several of DUKSUP's many major impacts on launches are discussed including Intelsat, Voyager, Pioneer Venus, HEAO, Galileo, and Cassini

School-Level Predictors of Academic and Athletic Success

The purpose of this study was to determine if specific school-level variables predict a high school’s academic performance and the success of its athletic department. A nonexperimental multivariate ex post facto correlational design and a group comparison design were employed in the study. Georgia public high schools competing in the GHSA classifications AAAAA, AAAA, and AAA during the academic years 2008-2010 were included in the study. Logistic regression was used to determine if the school-level variables predicted a school’s academic performance. A Mann-Whitney U test was used to determine if high-performing and low-performing schools were significantly different in terms of athletic department success. The predictor variables were able to accurately predict academic performance for over 82% of schools. While the percentage of minority students, graduation rate, and GHSGT scores were significant predictors in two out of the three classifications, the percentage of economically disadvantaged students was not a significant predictor. Significant differences existed between high-performing and low-performing schools in terms of overall athletic performance in GHSA classifications AAA and AAAA. Academic predictors (GHSGT scores and graduation rate) were linked to athletic achievement. Demographic variables (percentage of economically disadvantaged students and minority students) were significant predictors in classification AAA, but not in the larger classifications

Genomic prediction of dry matter intake in dairy cattle from an international data set consisting of research herds in Europe, North America, and Australasia

peer-reviewedFinancial support for gDMI from CRV (Arnhem, the Netherlands), ICBF (Cork, Ireland), CONAFE (Madrid, Spain), DairyCo (Warwickshire, UK) directly to the gDMI consortium, and The Natural Science and Engineering Research Council of Canada and DairyGen Council of Canadian Dairy Network (Guelph, ON, Canada) is gratefully appreciated, as well as the EU FP7 IRSES SEQSEL (Grant no. 317697).With the aim of increasing the accuracy of genomic estimated breeding values for dry matter intake (DMI) in Holstein-Friesian dairy cattle, data from 10 research herds in Europe, North America, and Australasia were combined. The DMI records were available on 10,701 parity 1 to 5 records from 6,953 cows, as well as on 1,784 growing heifers. Predicted DMI at 70 d in milk was used as the phenotype for the lactating animals, and the average DMI measured during a 60- to 70-d test period at approximately 200 d of age was used as the phenotype for the growing heifers. After editing, there were 583,375 genetic markers obtained from either actual high-density single nucleotide polymorphism (SNP) genotypes or imputed from 54,001 marker SNP genotypes. Genetic correlations between the populations were estimated using genomic REML. The accuracy of genomic prediction was evaluated for the following scenarios: (1) within-country only, by fixing the correlations among populations to zero, (2) using near-unity correlations among populations and assuming the same trait in each population, and (3) a sharing data scenario using estimated genetic correlations among populations. For these 3 scenarios, the data set was divided into 10 sub-populations stratified by progeny group of sires; 9 of these sub-populations were used (in turn) for the genomic prediction and the tenth was used for calculation of the accuracy (correlation adjusted for heritability). A fourth scenario to quantify the benefit for countries that do not record DMI was investigated (i.e., having an entire country as the validation population and excluding this country in the development of the genomic predictions). The optimal scenario, which was sharing data, resulted in a mean prediction accuracy of 0.44, ranging from 0.37 (Denmark) to 0.54 (the Netherlands). Assuming near-unity among-country genetic correlations, the mean accuracy of prediction dropped to 0.40, and the mean within-country accuracy was 0.30. If no records were available in a country, the accuracy based on the other populations ranged from 0.23 to 0.53 for the milking cows, but were only 0.03 and 0.19 for Australian and New Zealand heifers, respectively; the overall mean prediction accuracy was 0.37. Therefore, there is a benefit in collaboration, because phenotypic information for DMI from other countries can be used to augment the accuracy of genomic evaluations of individual countries.financial support for gDMI from CRV (Arnhem, the Netherlands), ICBF (Cork, Ireland), CONAFE (Madrid, Spain), DairyCo (Warwickshire, UK) directly to the gDMI consortium, and The Natural Science and Engineering Research Council of Canada and DairyGen Council of Canadian Dairy Network (Guelph, ON, Canada) is gratefully appreciated, as well as the EU FP7 IRSES SEQSEL (Grant no. 317697).financial support for gDMI from CRV (Arnhem, the Netherlands), ICBF (Cork, Ireland), CONAFE (Madrid, Spain), DairyCo (Warwickshire, UK) directly to the gDMI consortium, and The Natural Science and Engineering Research Council of Canada and DairyGen Council of Canadian Dairy Network (Guelph, ON, Canada) is gratefully appreciated, as well as the EU FP7 IRSES SEQSEL (Grant no. 317697)

Use-Exposure Relationships of Pesticides for Aquatic Risk Assessment

Field-scale environmental models have been widely used in aquatic exposure assessments of pesticides. Those models usually require a large set of input parameters and separate simulations for each pesticide in evaluation. In this study, a simple use-exposure relationship is developed based on regression analysis of stochastic simulation results generated from the Pesticide Root-Zone Model (PRZM). The developed mathematical relationship estimates edge-of-field peak concentrations of pesticides from aerobic soil metabolism half-life (AERO), organic carbon-normalized soil sorption coefficient (KOC), and application rate (RATE). In a case study of California crop scenarios, the relationships explained 90–95% of the variances in the peak concentrations of dissolved pesticides as predicted by PRZM simulations for a 30-year period. KOC was identified as the governing parameter in determining the relative magnitudes of pesticide exposures in a given crop scenario. The results of model application also indicated that the effects of chemical fate processes such as partitioning and degradation on pesticide exposure were similar among crop scenarios, while the cross-scenario variations were mainly associated with the landscape characteristics, such as organic carbon contents and curve numbers. With a minimum set of input data, the use-exposure relationships proposed in this study could be used in screening procedures for potential water quality impacts from the off-site movement of pesticides