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Necessary conditions for a multistage bolza- mayer problem involving control variables and having inequality and finite equation constraints

A multiplier rule and analogues of the Weierstrass and Clebsch conditions are developed for a multistage Bolza-Meyer calculus of variations problems. The number of stages is fixed, but partition points defining state boundaries are variable. Discontinuities are allowed in variables finite equations and inequalities, as well as differential equations, all of which involve control variables. An appendix summarizes some of the results obtained by C. H. Denbow, as modified by R. W. hunt, for a generalized Bolza problem. The appendix is independent of the rest of the paper.

Differential equation↗

Optimum Interplanetary Rendezvous Trajectories With Powerlimited Vehicles

The optimum-thrust equations for both variable and constant thrust are presented. These thrust programs are used to generate rendezvous trajectories from the Earth to Mars for various flight times and launch dates during the years 1968-71. The manner in which the propulsion requirements vary with flight time and launch date are considered, and a comparison of vehicle performance using the variable- and constant-thrust programs is presented. The optimization of the pro- pulsion system parameters is discussed, and the existence of optimum launch dates is interpreted in terms of certain transversality conditions derivable from the calculus of variations. A brief comparison of the advanced propulsion vehicle and the ballistic vehicle propulsion requirements is made for Earth-Mars rendezvous trajectories. An appendix considering the analytical basis for this work is included.

INTERPLANETARY TRAJECTORY↗

A Research Program in Flight Sciences

Since its inception in January 2003, thc program has provided support for 1 faculty and a total of 7 Graduate Research Scholar Assistants, of these all 7 have completed their MS degree program. The program has generated 5 MS thesis and 2 MS project reports. Attachment: Appendix A, B, C, and D.

Whitesides, John L.↗

Challenger STS-17 (41-G) post-flight best estimate trajectory products: Development and summary results

Results from the STS-17 (41-G) post-flight products are presented. Operational Instrumentation recorder gaps, coupled with the limited tracking coverage available for this high inclination entry profile, necessitated selection of an anchor epoch for reconstruction corresponding to an unusually low altitude of h approx. 297 kft. The final inertial trajectory obtained, BT17N26/UN=169750N, is discussed in Section I, i.e., relative to the problems encountered with the OI and ACIP recorded data on this Challenger flight. Atmospheric selection, again in view of the ground track displacement from the remote meteorological sites, constituted a major problem area as discussed in Section II. The LAIRS file provided by Langley was adopted, with NOAA data utilized over the lowermost approx. 7 kft. As discussed in Section II, the Extended BET, ST17BET/UN=274885C, suggests a limited upper altitude (H approx. 230 kft) for which meaningful flight extraction can be expected. This is further demonstrated, though not considered a limitation, in Section III wherein summary results from the AEROBET (NJ0333 with NJ0346 as duplicate) are presented. GTFILEs were generated only for the selected IMU (IMU2) and the Rate Gyro Assembly/Accelerometer Assembly data due to the loss of ACIP data. Appendices attached present inputs for the generation of the post-flight products (Appendix A), final residual plots (Appendix B), a two second spaced listing of the relevant parameters from the Extended BET (Appendix C), and an archival section (Appendix D) devoting input (source) and output files and/or physical reels.

Kelly, G. M.↗

Health Monitoring of RLV Airframe Structures

This final report is divided into three sections on health monitoring technologies: 1) Analysis of Optical Fiber Bragg Grating Sensor Data from Composite Wing Box Experiment; 2) Current Optical Fiber Bragg Grating Sensor Data Acquisition Design; and 3) Damages Identification of a Composite Plate by Prestack Reverse-Time Migration Technique. The report also includes an appendix, 'Group Velocities of Flexural Waves in a Composite Plate'.

Yuan, F. G.↗

Distribution and moments of radial error

An investigation of the moments and probability distribution of the resultant of two normally distributed random variables is presented. This is the so-called generalized Rayleigh distribution which has many applications in the study of wind shear, random noise, and radar. The most general formula was derived, and two special cases were considered for which tables of the moments and probability distribution functions are included as an appendix. One of the special cases was generalized to n-dimensions.

White, R. G.↗

United Nations principles on remote sensing - Report on developments, 1970-1980

The paper deals with the efforts of the United Nations Committee on the Peaceful Uses of Outer Space (COPUOS) to reach a consensus on legal principles governing the international use of remote sensing of the earth from space. The proceedings of the Working Group from 1971 to 1974 and the Legal Subcommittee from 1973 to 1980 are presented. Though the Committee has reached agreement on certain points, some key questions remain unresolved relative to dissemination of data and to the need for or method of classifying remote sensing data based on spatial resolution. An appendix of texts and draft principles worked out by COPUOS is also presented.

Mossinghoff, G. J.↗

Near infrared photographic sky survey - A field index

The book presents an index of previously cataloged objects located in the fields of the northern sky included in the Steward Observatory Near Infrared Photographic Sky Survey, which was intended to be used for identification purposes in an effort to locate extremely red objects. The objects included in the index were taken from 16 catalogs of bright nebulae, dark nebulae, infrared objects, reflection nebulae, supernova remnants and other objects, and appear with their corresponding field numbers, computed field center coordinates, object name and 1950 epoch equatorial coordinates, as well as supplementary descriptive information as available. An appendix is also provided in which the center coordinates of each field are listed.

Rossano, G. S.↗

Opportunities for Cooperation: Themis and RBSP

This document outlines potential joint scientific studies involving the THEMIS and RBSP missions as a function of mission phase from the commissioning of RBSP in August 2012 through the end of its prime mission in the summer of 2014. It describes consensus recommendations for interspace craft separation, fast survey and burst mode strategies for THEMIS that will enable the two missions to achieve and exceed their common objectives. An appendix describes the need for careful intercalibration of THEMIS and RBSP particle observations.

Sibeck, D. G.↗

Summary of airborne chlorine and hydrogen chloride gas measurements for August 20 and September 5, 1977 Voyager launches at Air Force Eastern Test Range, Florida

Airborne chlorine and hydrogen chloride measurements were made in the tropospheric ground cloud following the Voyager launches of August 20 and September 5, 1977. The maximum observed hydrogen chloride concentration for both launches was about 25 to 30 parts per million (ppm) occurring typically 2 to 6 minutes after launch. By completion of the sampling mission (1-1/2 hours for August, 4-1/2 hours for September), the maximum in-cloud concentration decayed to about 1 to 2 ppm. Maximum observed chlorine concentrations were about 40 to 55 parts per billion (ppb) about 2 to 8 minutes after launch; by about 15 minutes after launch, chlorine concentrations were less than 10 ppb (detection limit). In-cloud chlorine concentrations were well below 1 percent of hydrogen chloride concentrations. The appendix of the report discusses the chlorine instrument and the laboratory evaluation of the detector.

Gregory, G. L.↗

Quiet Clean Short-haul Experimental Engine (QCSEE). Aerodynamic and aeromechanical performance of a 50.8 cm (20 inch) diameter 1.34 PR variable pitch fan with core flow

The fan aerodynamic and aeromechanical performance tests of the quiet clean short haul experimental engine under the wing fan and inlet with a simulated core flow are described. Overall forward mode fan performance is presented at each rotor pitch angle setting with conventional flow pressure ratio efficiency fan maps, distinguishing the performance characteristics of the fan bypass and fan core regions. Effects of off design bypass ratio, hybrid inlet geometry, and tip radial inlet distortion on fan performance are determined. The nonaxisymmetric bypass OGV and pylon configuration is assessed relative to both total pressure loss and induced circumferential flow distortion. Reverse mode performance, obtained by resetting the rotor blades through both the stall pitch and flat pitch directions, is discussed in terms of the conventional flow pressure ratio relationship and its implications upon achievable reverse thrust. Core performance in reverse mode operation is presented in terms of overall recovery levels and radial profiles existing at the simulated core inlet plane. Observations of the starting phenomena associated with the initiation of stable rotor flow during acceleration in the reverse mode are briefly discussed. Aeromechanical response characteristics of the fan blades are presented as a separate appendix, along with a description of the vehicle instrumentation and method of data reduction.

Giffin, R. G.↗

Development of an Aeroelastic Analysis Including a Viscous Flow Model

Under this grant, Version 4 of the three-dimensional Navier-Stokes aeroelastic code (TURBO-AE) has been developed and verified. The TURBO-AE Version 4 aeroelastic code allows flutter calculations for a fan, compressor, or turbine blade row. This code models a vibrating three-dimensional bladed disk configuration and the associated unsteady flow (including shocks, and viscous effects) to calculate the aeroelastic instability using a work-per-cycle approach. Phase-lagged (time-shift) periodic boundary conditions are used to model the phase lag between adjacent vibrating blades. The direct-store approach is used for this purpose to reduce the computational domain to a single interblade passage. A disk storage option, implemented using direct access files, is available to reduce the large memory requirements of the direct-store approach. Other researchers have implemented 3D inlet/exit boundary conditions based on eigen-analysis. Appendix A: Aeroelastic calculations based on three-dimensional euler analysis. Appendix B: Unsteady aerodynamic modeling of blade vibration using the turbo-V3.1 code.

Keith, Theo G., Jr.↗