N89-27675# Naval Postgraduate School, Monterey, CA. (AD-A208512) Avail: NTIS HC A07/MF A01 CSCL 01/1 A 3-D numerical analysis of the Jet Engine Hush House located at Naval Air Station Jacksonville, Florida was developed using the PHOENICS computer code. The PHOENICS code was used to determine the steady state aerothermal characteristics in the Hush House produced by a Navy F-4 (Phantom 2) J-79-GE-8 gas turbine engine with afterburner. The PHOENICS generated pressure, velocity, and temperature fields of the test cell facility based on the k-epsilon turbulence model are compared with results generated by a model incorporating a temperature dependent kinematic turbulent viscosity. In addition, for the k-epsilon turbulence model, the effect of augmenter tube length on system behavior was investigated. Lessons learned and recommendations in obtaining a converged solution are included to aid in further applications of the PHOENICS code. GRA N89-27676# General Dynamics Corp., Fort Worth, TX. Atlee M. Cunningham, Jr., Todd Bushlow, John R. Mercer, Tim A. (Contract N00014-85-C-0419) (AD-A208539) Avail: NTIS HC A07/MF A01 CSCL 01/1 Force testing of small-scale models in either a small wind tunnel or a water tunnel was investigated as an inexpensive and quick means to obtain meaningful dynamic force and moment data representative of rapidly maneuvering full-scale aircraft. Force tests of flat-plate semi-span models were conducted in the General Dynamics Aerodynamic Development Facility (ADF) which is a small 14-in. x 14-in. low speed wind tunnel. Oscillatory model motions up to 48 deg (peak to peak) amplitude were tested at frequencies of 1 to 3 Hz. Force tests of flat and three-dimensional full span models were conducted in G.D.'s Hydroflow Facility (HFF) which is a horizontal flow water tunnel with a 24-in. x 24-in. test section. Pitch/pulse model motions were tested for conditions similar to those tested in the ADF. The test velocities were 100 fps in the ADF and 0.8 fps in the HFF which yielded nominal Reynolds numbers of 0.6 million and 0.06 million respectively (based on root chord). This volume presents the data base generated from tests in the ADF. The normal force, pitching moment and rolling moment data are in plotted and tabulated form for the straked wing, 55 deg and 70 deg delta wings and 70 deg/30 deg cranked wing semi-span models. Steady results along with unsteady results for two frequencies are included for the overall incidence range of 0 deg to 80 deg. Geometric data for the models are also given. GRA N89-27677# Melbourne Univ., Parkville (Australia). David S. Russell-Head and William F. Budd Apr. 1989 69 p Only small areas near the margins of the ice cap in Antarctica are ice-free, and only a few of these exposed sites are suitable for the construction of conventional runways. Wheeled aircraft have operated successfully on hard sea ice and exposed glacial ice, and skis have been fitted to a wide range of aircraft for use on snow. There has been a resurgence of interest in making snow runways suitable for use by conventional wheeled aircraft. Laboratory and field work has confirmed that low-density surface snow can be compacted in several ways to yield strong, uniform, load-bearing pavement that can support heavy wheeled aircraft. The Soviets have constructed several full-scale runways in Antarctica. This report provides some of the technical background for the design and construction of compacted-snow runways in Antarctica. The technology is not particularly difficult, and it's likely that the next few decades will see substantial changes to Antarctic air transportation as more snow runways are constructed GRA throughout the continent. N89-27678# Auburn Univ., AL. Dept. of Civil Engineering. A COMPARISON OF RUTTING BEHAVIOR OF ASPHALT CONCRETE UNDER THE F-4C/G AND F-15C/D AIRCRAFT Final Report, Jul. - Dec. 1987 James G. Murfee Jun. 1988 145 p (AF Proj. 2104) (AD-A208911; AFESC/ESL-TR-88-48) Avail: NTIS HC A07/MF A01 CSCL 13/2 The effect of the F-4 and the F-15 aircraft on rutting performance of standard airfield bituminous mixtures during hot weather conditions were compared. The comparisons and conclusions herein were drawn from trafficking new 4 inch asphalt concrete overlying 12 inches of Portland cement concrete. The asphalt concrete was produced from Ac-30 asphalt cement and 100 percent crushed limestone of 3/4 inch maximum size. Pavement surface temperatures ranged from 80 to 122 F during traffic. Both test strips were trafficked simultaneously, back and forth, in a channelized manner 6,000 times by loadcarts that simulated the heaviest designs of F-4 and F-15 aircraft. In one strip, the F-4 loadcart test wheel was loaded to 27.1 kips with cold tire inflation pressures of 265 psi. In the other strip, the F-15 loadcart test wheel was loaded to 30.5 kips with cold tire inflation pressure of 355 psi. It was learned that it takes 5,000 passes of the F-4 to produce a 0.4 inch rut depth in this particular mix, but only 1,000 passes of the F-15. This rut depth of 0.4 inch was far from failure of the layer and was the maximum reached in the F-4 test strip. The dominant mode of rutting was densification with plastic flow of the mixture estimated to have caused about 12 percent of the rutting. GRA N89-27679# Dayton Univ., OH. Research Inst. James A. Kleiss and David C. Hubbard May 1989 24 p Altitude control in simulated low-level flight improves significantly when three-dimensional objects are added to simulator visual scenes. However, the limited processing capacity of computer image generators (CIGs) may be used either to increase the density of objects at the expense of individual object detail and realism, or to increase the detail of objects at the expense of object density. The present investigation sought to determine whether object density or object detail is the more important factor in simulated low-level flight. Three types of three-dimensional object were employed: (1) control condition consisting of inverted tetrahedrons (the simplest possible three-dimensional shape); (2) highly detailed and realistic pine tree; and (3) a mixture of oak trees, pine trees, and bushes. The four levels of object density employed ranged from 3 objects per square mile to 175 objects per square mile. The task required a perceptual judgement to discriminate a change in altitude and a control action to reestablish the initial target altitude. Results indicated that object density had a greater effect on performance. Limited CIG processing capacity may, therefore, be more effectively used by increasing object density rather than individual object detail. GRA For Global Positioning System (GPS) satellite orbit determination, the most accurate observable available is carrier phase, differenced between observing stations and between satellites to cancel both transmitter and receiver related errors. For maximum accuracy, the integer cycle ambiguities of such observations must be resolved. To perform this ambiguity resolution, a bootstrapping strategy is effective. This strategy requires the tracking stations to have a wide ranging progression of spacings. Then, by conventional integrated Doppler processing of the observations from the most widely spaced stations, the orbits can be determined well enough to permit resolution can reduce the uncertainty of the orbit determination enough to enable ambiguity resolution for more widely spaced stations, which will reduce the orbital uncertainty further, and enable ambiguity resolution for still more widely spaced stations, and so on. This strategy is tested with two different tracking networks. This limited ambiguity resolution reduced both the formal and the actual errors of GPS orbit determinations by a factor of two. In the second twelve stations were arranged in a spiral with geometrically increasing spacings from 10 to 330 km. By bootstrapping, all ambiguities for baselines up to about 100 km long were resolved. The distance was limited by strong ionospheric variability. Still, orbit-determination uncertainty (3 sigma) was reduced to about 1:1,000,000. GRA No abstracts in this category. 13 ASTRODYNAMICS Includes powered and free-flight trajectories; and orbital and launching dynamics. N89-27680# Instituto de Pesquisas Espaciais, Sao Jose dos OPTIMIZATION OF MANEUVERS OF A SPIN-STABILIZED [OTIMIZACAO DE MANOBRAS DE SATELITES ESTABILIZADOS POR SPIN, UTILIZANDO BOBINAS Victor Orlando GamarraRosado Dec. 1988 86 P In (INPE-4778-TDL/350) Avail: NTIS HC A05/MF A01 Open-loop controls are developed which minimize the attitude maneuver time of a spin-stabilized satellite through the optimization of both polarity and time intervals of actuation of a magnetic coil type actuator. The maneuver control torque is generated by the interaction between the magnetic moment of this coil and the geomagnetic field. The proposed maneuver optimization consists of two phases, both with suboptimal approaches: (1) the optimization of the coil's operating intervals, covering every orbital period separately; and (2) the maneuver global optimization, using the intervals obtained in the previous phase as the starting parameters. The theoretical foundations for the formulation of the problem, the modelling of the satellite attitude dynamics, the optimization treatment to obtain the control, and numerical tests to evaluate the behavior of the procedure are presented. Simulations have verified the feasibility of formulating and obtaining the proposed optimal control. Author N89-27681# Massachusetts Inst. of Tech., Cambridge. R. E. Abbot, C. C. Counselman, III, S. A. Gourevitch, and J. W. (Contract F19628-86-K-0009) (AD-A209974; AFGL-TR-89-0039; SR-3) Avail: NTIS HC A03/MF A01 CSCL 22/3 MD. SMALL SCALE TESTING OF A MASS-STABILIZED James M. Garner and Alexander E. Zielinski Mar. 1989 31 p (AD-A206916; BRL-MR-3740) Avail: NTIS HC A03/MF A01 CSCL 19/1 Few electromagnetic (EM) gun projectiles that incorporate aerodynamic aspects have been fired from an EM gun. A practical EM gun projectile, to be used in atmospheric conditions, should consider how efficiently the projectile package is accelerated as well as the flight characteristics. This report details the firing of a full-bore projectile from an electromagnetic gun. Background projectile design criteria, test procedures, and results are GRA discussed. The launch window studies establish a relatively significant phase in mission analysis of a given space program. The final result of such an analysis is the time interval of the day during some particular days of the year in which the spacecraft launch could be achieved. The main task is to identify and to formulate mathematically, the several constraints concerning the launch that restrain or modify the launch window. An overview is presented of the launch window studies made for the Data Collecting Satellite (DCS) of the Brazilian Space Program (MECB). Author N89-27684# Army Stategic Defense Command, Huntsville, AL. HIGH ENDOATMOSPHERIC DEFENSE INTERCEPTOR (HEDI) TECHNOLOGY TESTING PROGRAM ENVIRONMENTAL ASSESSMENT Dru Barrineau 31 May 1989 231 p (AD-A210006) Avail: NTIS HC A11/MF A01 CSCL 15/3 The High Endoatmospheric Defense Interceptor (HEDI) is one of the many technologies being considered in the strategic defense initiative (SDI) technology research program and has the potential to support the requirements for the strategic defense system. The purpose of this environmental assessment (EA) is to analyze the environmental consequences of testing activities for the HEDI technology test program in compliance with the National Environmental Policy Act. The HEDI is a technology that would employ ground-based missiles to intercept and destroy hostile submarine-launched ballistic missiles and intercontinental ballistic missiles during that portion of flight that puts the target in the high endoatmosphere (the terminal portion of an attacking missile trajectory). The HEDI vehicle would consist of a two-stage launch vehicle (booster) and kill vehicle with a conventional warhead. The basic thrust of the efforts already accomplished has been to assess the operational utility of HEDI in the context of a complete strategic defense system. GRA (Contract F33615-81-C-3617) (AD-A210128; AFWAL-TR-86-3091-Vol-2) Avail: NTIS HC A07/MF A01 CSCL 16/4 The computer code is capable of addressing a wide variety of conventional missile designs. For the purposes of this document, a conventional missile is one which is comprised of the following: an axisymmetric or elliptically-shaped body, one to four fin sets located along the body between the nose and base. Each fin set can be comprised of one to eight identical panels attached around the body at a common longitudinal position, and an airbreathing propulsion system. To minimize the quantity of input data required, commonly used values for many inputs are assumed as defaults. However, all program defaults can be over-ridden by the user in order to more accurately model the configuration of interest. GRA 16 SPACE TRANSPORTATION Includes passenger and cargo space transportation, e.g., shuttle operations; and space rescue techniques. For related information see also 03 Air Transportation and Safety and 18 Spacecraft Design, Testing and Performance. For space suits see 54 Man/System Technology and Life Support. N89-27686# Battelle Columbus Labs., OH. ENVIRONMENTAL EFFECTS OF SPACE SHUTTLE EXHAUST ON MATERIALS Final Report, Apr. 1986 - Aug. 1987 W. H. Abbott Jan. 1989 42 p (Contract F08635-85-C-0122; AF Proj. 1900) (AD-A208813; AFESC/ESL-TR-87-71) Avail: NTIS HC A03/MF A01 CSCL 22/5 Studies were conducted at Vandenberg Air Force Base to monitor the indoor environments associated with ground-based electronics at Shuttle Launch Complex 6 (SLC-6). Phase 1, which is summarized in this report, was designed to determine baseline data prior to first launch of the space shuttle from this facility. During the course of the program, additional but similar studies were made at Vandenberg SLC-4 and Sunnyvale Air Force Station. Results at SLC-6 showed very low indoor pollutant levels, particularly with respect to reactive chlorides. Severity levels, as defined by corrosion monitoring, were exceptionally low at all locations, indicating that baseline conditions were very satisfactory for modern electronics. However, humidity and humidity cycling problems associated with HVAC operations were demonstrated at several locations. This raised the possibility for high corrosion rates on electronic components where reactive chloride infiltration occurred. Significantly higher chloride levels were detected at SLC-4 for both prelaunch and post launch environments. This site was considered marginal with respect to both analyzed and potential corrosion phenomena on electronics. 17 SPACE COMM., SPACECRAFT COMM., COMMAND & TRACKING GRA Includes telemetry; space communications networks; astronavigation and guidance; and radio blackout. For related information see also 04 Aircraft Communications and Navigation and 32 Communications and Radar. S. J. Katzberg et al 28 Apr. 1989 738 p (NASA-TM-101586-Vol-1; NAS 1.15:101586-Vol-1) Avail: NTIS HC A99/MF E03 CSCL 22B The results of a NASA in-house team effort to develop a concept definition for a Commercially Developed Space Facility (CDSF) are presented. Science mission utilization definition scenarios are documented, the conceptual configuration definition system performance parameters qualified, benchmark operational scenarios developed, space shuttle interface descriptions provided, and development schedule activity was assessed with respect to the establishment of a proposed launch date. Author N89-27691# Boston Coll., Chestnut Hill, MA. Space Data Analysis Lab. DATABASE DEVELOPMENT FOR THE DMSP (DEFENSE METEOROLOGICAL SATELLITE PROGRAM) SSIES EXPERIMENT Scientific Report No. 1, 1 Jan. 1987 - 31 Dec. 1988 Dennis E. Delorey, Paul N. Pruneau, and Carolyn M. Parsons 28 Feb. 1989 41 p (Contract F19628-87-K-0008; AF Proj. 7601) (AD-A208712; BC-SDAL-89-1; GL-TR-89-006; SR-1) Avail: NTIS CSCL 04/1 HC A03/MF A01 Processed data bases for the Special Sensor for lons, Electrons and Scintillators (SSIES) experiments flown on-board the F8 and F9 DMSP vehicles have been created over the lifetime of the two satellites. An historical overview of the DMSP project is presented. The data processing system developed for the SSIES experiments, the payloads on-board the spacecraft and the computer software associated with the data processing are described. The formats of the data bases associated with each phase of the processing are described. GRA N89-27692# Massachusetts Inst. of Tech., Cambridge. FEASIBILITY OF MILLIMETER-ACCURACY GEODETIC POSITIONING AND VEHICLE TRACKING WITH REPEATER SATELLITES M.S. Thesis Laureano A. Cangahuala 27 Jan. 1989 77 p (Contract F19628-86-K-0009) (AD-A209958; AFGL-TR-89-0031; SR-2) Avail: NTIS HC A05/MF A01 CSCL 08/5 The feasibility of the GeoBeacon system is studied. In this system, low power radio transmitters are placed on vehicles or at other points whose positions are to be monitored. Tropospheric and ionospheric refraction are also monitored. The number of transmitters is practically unlimited. Signals from all transmitters in view are repeated by satellites to a central site where detection, measurement, and data processing take place. To enable precise geodetic positioning, signals would be emitted at multiple frequencies, including relatively low (e.g., 100 MHz) and relatively high (several GHz) frequencies. The lower frequency signals would aid in the acquisition and tracking of the higher frequency signals in order to reduce transmitter power requirements. Power requirements are calculated as functions of frequency from 100 MHz to 50 GHz, considering both natural phenomena and interference from accidental and intentional radio transmissions. An algorithm is developed for the selection of frequencies by which aided tracking of the highest frequency signal can be maintained. This algorithm is based on a stochastic description of the kinematic and ionospheric contributions to the received signal frequencies and phases. Discrete Kalman filter equations are derived for estimating the covariances of phase and frequency estimates. GRA N89-28236# Dept. Contraves Corp., Zurich (Switzerland). Space THE SPACE-RIGIDISED THERMAL SHIELD FOR THE ESA (Contract ESTEC-6324/85/NL/PB(SC)) Copyright Avail: NTIS HC A99/MF A01; ESA Publications Div., ESTEC, Noordwijk, Netherlands, 80 Dutch guilders or 45 US dollars N89-28251# Dornier System G.m.b.H., Friedrichshafen (Germany, THERMAL ANALYSIS OF ROSAT IN LOW-EARTH ECLIPSE K. Honnen In ESA, Third European Symposium on Space Thermal Control and Life Support Systems Dec. 1988 P 267-271 (For primary document see N89-28214 22-54) N89-28256# Aeritalia S.p.A., Turin (Italy). THE THERMAL CONTROL OF EUTELSAT-2 E. Sacchi and M. Koedinger (Aerospatiale, Cannes La Bocca, Avail: NTIS HC A99/MF A01; ESA Publications Div., ESTEC, Noordwijk, Netherlands, 80 Dutch guilders or 45 US dollars N89-28257# Aerospatiale, Cannes La Bocca (France). A. Lanteri and B. Henning (Telefonaktiebolaget L. M. Ericsson, p 319-326 (For primary document see N89-28214 22-54) Copyright Avail: NTIS HC A99/MF A01; ESA Publications Div., ESTEC, Noordwijk, Netherlands, 80 Dutch guilders or 45 US dollars N89-28258# Fokker B.V., Amsterdam (Netherlands). Space and Systems Div. A THERMAL CONTROL DESIGN FOR THE QUASAT H. Petersen In ESA, Third European Symposium on Space N89-28259# Aerospatiale, Cannes La Bocca (France). S. Zaninotti In ESA, Third European Symposium on Space p 333-337 (For primary document see N89-28214 22-54) Copyright Avail: NTIS HC A99/MF A01; ESA Publications Div., ESTEC, Noordwijk, Netherlands, 80 Dutch guilders or 45 US dollars N89-28260# Fokker B.V., Amsterdam (Netherlands). Space and Systems Div. PREPARING ULYSSES FOR LAUNCH H. Petersen In ESA, Third European Symposium on Space Thermal Control and Life Support Systems Dec. 1988 p 339-344 (For primary document see N89-28214 22-54) Copyright Avail: NTIS HC A99/MF A01; ESA Publications Div., ESTEC, Noordwijk, Netherlands, 80 Dutch guilders or 45 US dollars N89-28261# Dornier System G.m.b.H., Friedrichshafen (Germany, THERMAL ASPECTS OF THE ERS-1 SAR ANTENNA G. Jander, F. Zilly, and R. Bisanz In ESA, Third European |