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At least 253 records · Page 14

Space Shuttle Orbiter Approach and Landing Test: Final Evaluation Report

The Approach and Landing Test Program consisted of a series of steps leading to the demonstration of the capability of the Space Shuttle orbiter to safely approach and land under conditions similar to those planned for the final phases of an orbital flight. The tests were conducted with the orbiter mounted on top of a specially modified carrier aircraft. The first step provided airworthiness and performance verification of the carrier aircraft after modification. The second step consisted of three taxi tests and five flight tests with an inert unmanned orbiter. The third step consisted of three mated tests with an active manned orbiter. The fourth step consisted of five flights in which the orbiter was separated from the carrier aircraft. For the final two flights, the orbiter tail cone was replaced by dummy engines to simulate the actual orbital configuration. Landing gear braking and steering tests were accomplished during rollouts following the free flight landings. Ferry testing was integrated into the Approach and Landing Test Program to the extent possible. In addition, four ferry test flights were conducted with the orbiter mated to the carrier aircraft in the ferry configuration after the free-flight tests were completed.

Source record↗

Concentrating solar collector - final design

Final report of program to improve commercially available concentrating solar collector describes final hardware, discusses problems encountered, and presents certification statements, photographs, and recommendations for modification.

Parker, J. C.↗

Final design and fabrication of an active control system for flutter suppression on a supercritical aeroelastic research wing

The final design and hardware fabrication was completed for an active control system capable of the required flutter suppression, compatible with and ready for installation in the NASA aeroelastic research wing number 1 (ARW-1) on Firebee II drone flight test vehicle. The flutter suppression system uses vertical acceleration at win buttock line 1.930 (76), with fuselage vertical and roll accelerations subtracted out, to drive wing outboard aileron control surfaces through appropriate symmetric and antisymmetric shaping filters. The goal of providing an increase of 20 percent above the unaugmented vehicle flutter velocity but below the maximum operating condition at Mach 0.98 is exceeded by the final flutter suppression system. Results indicate that the flutter suppression system mechanical and electronic components are ready for installation on the DAST ARW-1 wing and BQM-34E/F drone fuselage.

Hodges, G. E.↗

Final STS-11 (41-B) best estimate trajectory products: Development and results from the first Cape landing

The STS-11 (41-B) postflight data processing is completed and the results published. The final reconstructed entry trajectory is presented. The various atmospheric sources available for this flight are discussed. Aerodynamic Best Estimate of Trajectory BET generation and plots from this file are presented. A definition of the major maneuvers effected is given. Physical constants, including spacecraft mass properties; final residuals from the reconstruction process; trajectory parameter listings; and an archival section are included.

Kelly, G. M.↗

The final COS-B database now publicly available

The data obtained by the gamma ray satellite COS-B was processed, condensed and integrated together with the relevant mission and experiment parameters into the Final COS-B Database. The database contents and the access programs available with the database are outlined. The final sky coverage and a presentation of the large scale distribution of the observed Milky Way emission are given. The database is announced to be available through the European Space Agency.

Mayer-Hasselwander, H. A.↗

Final stages of transition to turbulence in plane channel flow

This paper involves a numerical simulation of the final stages of transition to turbulence in plane channel flow at a Reynolds number of 1500. Three-dimensional incompressible Navier-Stokes equations are numerically integrated to obtain the time evolution of two- and three-dimensional finite-amplitude disturbances. Computations are performed on the CYBER-203 vector processor for a 32 x 51 x 32 grid. Solutions indicate the existence of structures similar to those observed in the laboratory and characteristics of the various stages of transition that lead to final breakdown. In particular, evidence points to the formation of a upside-down-V-shaped vortex and the subsequent system of horseshoe vortices inclined to the main flow direction as the primary elements of transition. Details of the resulting flow field after breakdown indicate the evolution of streaklike formations found in turbulent flows. Although the flow field does approach a steady state (turbulent channel flow), the introduction of subgrid-scale terms seems necessary to obtain fully developed turbulence statistics.

Biringen, S.↗

Simulated final approach path captures using the microwave landing system

Computer simulation results are presented for intercepting final approach paths using various Microwave Landing System (MLS) path capture concepts. This study, conducted under the Advanced Transport Operating System (ATOPS) program, simulated these captures using the MD-80 aircraft as the study model. Several different capture concepts were investigated. Systems that could be retrofitted into existing aircraft with minimum hardware and software changes were considered. An enhanced ILS look-alike capture provided improved tracking performance over conventional ILS without using a full-up path computer. The other concepts used waypoint databases and path computers to provide smart captures. These captures included lateral path intercepts as well as vertical path control. Winds, turbulence, and MLS noise were included in the simulation. In all cases, acceptable tracking errors were obtained during transition to the final approach path.

Feather, J. B.↗

A study of the stratospheric final warming of 1982 in the Southern Hemisphere

Data obtained from stratospheric sounding units on board the NOAA-6 satellite were used to investigate the three-dimensional evolution of the final warming that takes place in the stratosphere of the Southern Hemisphere during spring, with particular attention given to the events of spring 1982. Evidence is presented for a strong influence of the topography of the Southern Hemisphere on the evolution of the final warming. An association was found between the location of anticylones in the upper stratosphere, warm pools of air in the lower stratosphere, and a climatological split of the westerly jet stream in the upper troposphere.

Mechoso, C. R.↗

Simulator evaluation of the final approach spacing tool

The design and simulator evaluation of an automation tool for assisting terminal radar approach controllers in sequencing and spacing traffic onto the final approach course is described. The automation tool, referred to as the Final Approach Spacing Tool (FAST), displays speed and heading advisories for arrivals as well as sequencing information on the controller's radar display. The main functional elements of FAST are a scheduler that schedules and sequences the traffic, a 4-D trajectory synthesizer that generates the advisories, and a graphical interface that displays the information to the controller. FAST was implemented on a high performance workstation. It can be operated as a stand-alone in the Terminal Radar Approach Control (TRACON) Facility or as an element of a system integrated with automation tools in the Air Route Traffic Control Center (ARTCC). FAST was evaluated by experienced TRACON controllers in a real-time air traffic control simulation. Simulation results show that FAST significantly reduced controller workload and demonstrated a potential for an increase in landing rate.

Davis, Thomas J.↗

Flight set 360L007 (STS-33) insulation component. Volume 3: Final release

Volume 3 of this postfire report deals with the insulation component of the RSRM. The report is released twice for each flight set. The interim release contract date is on or before 60 days after the last field joint or nozzle to case joint is disassembled at KSC and contain the results of the KSC visual evaluation. The data contained in Volume 3 interim release supersedes the insulation data presented in the KSC 10 day report. The final release contract data is on or before 60 days after the last factory joint is disassembled at the Clearfield H-7 facility and contains the results of all visual evaluations and a thermal safety factor analysis. The data contained in the Volume 3 final release supersedes the interim release and the insulation data presented in the Clearfield 10 day report.

Hicken, Steve↗

Simulator evaluation of the Final Approach Spacing Tool

The design and simulator evaluation of an automation tool for assisting terminal radar approach controllers in sequencing and spacing traffic onto the final approach course is described. The automation tool, referred to as the Final Approach Spacing Tool (FAST), displays speed and heading advisories for arrivals and sequencing information on the controller's radar display. The main functional elements of FAST are a scheduler that schedules and sequences the traffic, a four-dimensional trajectory synthesizer that generates the advisories, and a graphical interface that displays the information to the controller. FAST has been implemented on a high-performance workstation. It can be operated stand-alone in the terminal radar approach control (TRACON) facility or as an element of a system integrated with automation tools in the Air Route Traffic Control Center). Simulation results show that FAST significantly reduced controller workload and demonstrated a potential for an increase in landing rate.

Davis, Thomas J.↗

Design and evaluation of an air traffic control Final Approach Spacing Tool

This paper describes the design and simulator evaluation of an automation tool for assisting terminal radar approach controllers in sequencing and spacing traffic onto the final approach course. The automation tool, referred to as the Final Approach Spacing Tool (FAST), displays speed and heading advisories for arriving aircraft as well as sequencing information on the controller's radar display. The main functional elements of FAST are a scheduler that schedules and sequences the traffic, a four-dimensional trajectory synthesizer that generates the advisories, and a graphical interface that displays the information to the controller. FAST has been implemented on a high-performance workstation. It can be operated as a stand-alone in the terminal radar approach control facility or as an element of a system integrated with automation tools in the air route traffic control center. FAST was evaluated by experienced air traffic controllers in a real-time air traffic control simulation. simulation results summarized in the paper show that the automation tools significantly reduced controller work load and demonstrated a potential for an increase in landing rate.

Davis, Thomas J.↗

Shaving Ceramic Tiles To Final Dimensions

Combination of template and routing tool cuts ceramic tiles to final dimensions. Template guides router along precisely defined planes to accurately and uniformly shave chamfers on edge of tiles. Legs of template temporarily bonded to workpiece by double-backed adhesive tape. Adaptable to in-situ final machining of other nominally flat, narrow surfaces.

Shaw, Ernest↗

Final design report of a personnel launch system and a family of heavy lift launch vehicles

The objective was to design both a Personnel Launch System (PLS) and a family of Heavy Lift Launch Vehicles (FHLLVs) that provide low cost and efficient operation in missions not suited for the Shuttle. The PLS vehicle is designed primarily for space station crew rotation and emergency crew return. The final design of the PLS vehicle and its interior is given. The mission of the FHLLVs is to place large, massive payloads into Earth orbit with payload flexibility being considered foremost in the design. The final design of three launch vehicles was found to yield a payload capacity range from 20 to 200 mt. These designs include the use of multistaged, high thrust liquid engines mounted on the core stages of the rocket.

Tupa, James↗

Final design proposal: Theta Group-The Hotbox. A proposal in response to a commercial air transportation study

The Hotbox is a 40 passenger commercial aircraft designed to have a minimum range of 5500 ft and cruise at a velocity of 30 ft/sec. The aircraft is designed to serve the longer range overseas market in Aeroworld. In order to serve all the airports in the overseas market, the Hotbox was required to be able to use a five foot gate. A weight requirement was set a 4.5 lbs in order to maximize aircraft efficiency. Finally, a single engine system was chosen because it minimized system weight, complexity and cost. The Hotbox is estimated to cost $152,000 Aeroworld dollars and will sell for $200.000. The propulsion system for the Hotbox consists of a nose mounted Astro 15 electric powered motor and a Top Flight 12-6 propeller. A Spica airfoil was selected for the Hotbox based on the ease of construction of its flat bottom and its positive lift and drag characteristics. A fuselage of rectangular cross section will internally contain the propulsion system, control system, and a passenger bay with 2x20 seating. A combination of directional and longitudinal control will enable the Hotbox to maneuver. The final design of the Hotbox provides for takeoff distance in 26.5 ft and normal cruise range of 17,000 ft.

Source record↗

State-selected chemical reaction dynamics at the S matrix level - Final-state specificities of near-threshold processes at low and high energies

State-to-state reaction probabilities are found to be highly final-state specific at state-selected threshold energies for the reactions O + H2 yield OH + H and H + H2 yield H2 + H. The study includes initial rotational states with quantum numbers 0-15, and the specificity is especially dramatic for the more highly rotationally excited reactants. The analysis is based on accurate quantum mechanical reactive scattering calculations. Final-state specificity is shown in general to increase with the rotational quantum number of the reactant diatom, and the trends are confirmed for both zero and nonzero values of the total angular momentum.

Chatfield, David C.↗

Design definition of the Laser Atmospheric Wind Sounder (LAWS), phase 2. Volume 2: Final report

Lockheed personnel, along with team member subcontractors and consultants, have performed a preliminary design for the LAWS Instrument. Breadboarding and testing of a LAWS class laser have also been performed. These efforts have demonstrated that LAWS is a feasible Instrument and can be developed with existing state-of-the-art technology. Only a commitment to fund the instrument development and deployment is required to place LAWS in orbit and obtain the anticipated science and operational forecasting benefits. The LAWS Science Team was selected in 1988-89 as were the competing LAWS phase 1/2 contractor teams. The LAWS Science Team developed requirements for the LAWS Instrument, and the NASA/LAWS project office defined launch vehicle and platform design constraints. From these requirements and constraints, the lockheed team developed LAWS Instrument concepts and configurations. A system designed to meet these requirements and constraints is outlined. The LAWS primary subsystem and interfaces - laser, optical, and receiver/processor - required to assemble a lidar are identified. Also identified are the support subsystems required for the lidar to function from space: structures and mechanical, thermal, electrical, and command and data management. The Lockheed team has developed a preliminary design of a LAWS Instrument System consisting of these subsystems and interfaces which will meet the requirements and objectives of the Science Team. This final report provides a summary of the systems engineering analyses and trades of the LAWS. Summaries of the configuration, preliminary designs of the subsystems, testing recommendations, and performance analysis are presented. Environmental considerations associated with deployment of LAWS are discussed. Finally, the successful LAWS laser breadboard effort is discussed along with the requirements and test results.

Wilson, D. J.↗

Two neural network algorithms for designing optimal terminal controllers with open final time

Multilayer neural networks, trained by the backpropagation through time algorithm (BPTT), have been used successfully as state-feedback controllers for nonlinear terminal control problems. Current BPTT techniques, however, are not able to deal systematically with open final-time situations such as minimum-time problems. Two approaches which extend BPTT to open final-time problems are presented. In the first, a neural network learns a mapping from initial-state to time-to-go. In the second, the optimal number of steps for each trial run is found using a line-search. Both methods are derived using Lagrange multiplier techniques. This theoretical framework is used to demonstrate that the derived algorithms are direct extensions of forward/backward sweep methods used in N-stage optimal control. The two algorithms are tested on a Zermelo problem and the resulting trajectories compare favorably to optimal control results.

Plumer, Edward S.↗