Search Results

The system that will be presented consists of a Crawling Portable Robot (CPR) for drilling large air frame components as a part of the whole assembly process of fuselage or wing type sub-structures. Currently, the drilling of such components is massively fulfilled manually in a very labour intensive and “craft-based” manner. The operations are conducted in cramped, dangerous conditions and often involve unhealthy postures. The alternative to this situation consists in the use of large fixed-base multi-axis machines mounted upon a foundation on the shop floor. These machines are quite expensive, and also have a number of operational limitations. Because of their large working envelope, it is difficult for these machines to hold close tolerances over the entire range of all movement axes of the machine. Hence, there is a need to probe and calibrate the machine to the workpiece one or more times during work operations with the consequent negative impact in productivity.

This test method describes a procedure for determining the insoluble contamination level of the downstream side of filter elements. Results of this procedure are intended to be used only for evaluation of the effectiveness of various cleaning treatments, or cleanliness of element as received from manufacturers. The data obtained by this procedure do not necessarily indicate, qualitatively or quantitatively, the contamination which may be released by a filter element into a fluid during service use. Because of the wide variety of conditions which may exist in service applications, it is recommended that the user design and conduct his own particular service performance test. (See paragraph 10.1).

Ames Research Center’s Life Sciences Division has developed and flown an extensive array of spaceflight experiment unique equipment (EUE) during the last decade of the twentieth century. Over this ten year span, the EUE developed at ARC supported a vital gravitational biology flight research program executed on several different platforms, including the Space Shuttle, Spacelab, and Space Station Mir. This paper highlights some of the key EUE elements developed at ARC and flown during the period 1990-1999. Resulting lessons learned will be presented that can be applied to the development of similar equipment for the International Space Station.

The Deployable Vegetable Production System (VEGGIE) was originally developed as a way to produce fresh vegetables on the ISS with minimal resources. We are reassessing this system for use in lunar habitats to produce palatable, nutritious, and safe fresh food, provide a recreational tool, and provide a platform to support biological life support development by allowing in situ study of crop productivity and air and water revitalization. The VEGGIE system consists of plant growth chambers that can be stowed in a volume less than 10% of their deployed volume, while still providing the light output and root zone capabilities necessary to support high plant productivity rates. The system has significantly reduced logistical and operational requirements compared to other plant growth systems, and is of a modular design to allow logistical flexibility in terms of transport options and placement in a habitat structure.

A questionnaire study was conducted to determine the present state-of-the-art in the field of design tool (research and development) flight simulators. The major concern at this time appears to be the simulation of realistic external displays for visual reference by the pilot. Advance study is vitally necessary in the fields of VTOL/ STOL performance.stability and control, and instrumentation and/ or displays for terrain clearance and avoidance during high speed, low altitude flight. Also required are studies of g forces, zero g environment, and the use of drugs or hypnosis to control specific channels of communication in man during studies of his more significant sensors.

The National Aeronautics and Space Administration (NASA) is preparing for a manned mission to Mars to test the sustainment of civilization on the planet Mars. This research explores the requirements and feasibility of autonomously producing fuel on Mars for a return trip back to Earth. As a part of NASA’s initiative for a manned trip to Mars, our team’s work creates and analyzes the allocation of resources necessary in deploying a fuel station on this foreign soil. Previous research has addressed concerns with a number individual components of this mission such as power required for fuel station and tools; however, the interactions between these components and the effects they would have on the overall requirements for the fuel station are still unknown to NASA. By creating a baseline discrete-event simulation model in a simulation software environment, the research team has been able to simulate the fuel production process on Mars.

The SCARLETT European Research Project has the goal to define, develop and validate the concepts of the next generation of IMA (IMA2G). Enhanced File Management capability is central to support next generation IMA Platform properties and the increasing usage of memory mass storage. IMA2G Applications require access to data stored on mass memory independent from their physical location across the Platform; Platform-wide File Services are required. We provide, in the framework of the SCARLETT project, a distributed approach to File Management, which meets the IMA2G requirements. The proposed design aims to move from a module-centric File Management, typical in IMA1G, to a Platform-centric File Management based on a distributed file stack. After examining existing IMA standard solutions concerning File Management, an overview of the ‘Platform File Management’ architecture is given.

The future of human exploration in the solar system is contingent on the ability to exploit resources in-situ to produce mission consumables. Specifically, it has become clear that the success of a manned mission to Mars will likely depend on fuel components created on the Martian surface. While several architectures for an unmanned fuel production surface facility on Mars exist in theory, a simulation of the performance and operation of these architectures has not been created. In this paper, the framework describing a simulation of one such architecture is defined. Within this architecture, each component of the base is implemented as a state machine, with the ability to communicate with other base elements as well as a supervisor. An environment supervisor is also created which governs low level aspects of the simulation such as movement and resource distribution, in addition to higher-level aspects such as location selection with respect to operations specific behavior.

The Ducted Propulsor is proposed as a means of quiet propulsion. In order to demonstrate that very low levels can be realistically achieved, a unit has been built based on a conventional 285 h.p. aircraft reciprocating engine. The problems associated with the design of such a power plant, which include keeping the cost and weight of a production unit in perspective, are discussed along with the chosen solution. The test results will be published later.

A dynamic simulation model has been developed for a vapor-cycle cooling system designed for aircraft applications using the latest technology developments. The heat exchanger models use multiple-, lumped-parameter, fixed-length elements based on coupled thermal and mass storage effects, and flow equations that incorporate the effects of thermal expansion and contraction. This model is developed to include the two-phase constant pressure temperature gradient unique to refrigerant mixtures. The full system model incorporates global mass conservation which is essential for accurate pressure levels and, thus, dynamic response and steady state performance. Phase boundary-based coordinate transformations on the nonazeotropic refrigerant mixture property data result in improved accuracy and computation efficiency. The simulation is developed with modular components with causality defined to minimize connection states and thus execution time.

A discussion is given of the ongoing research related to laminar flow airfoils, nacelles, and wings where the laminar flow is maintained by a favorable pressure gradient, surface suction or a combination of the two. Design methologies for natural laminar flow airfoil sections and wings for both low and high speed applications are outlined. Tests of a 7-foot chord, 23° sweep laminar-flow-control-airfoil at high subsonic Mach numbers are described along with the associated stability theory used to design the suction system. The state-of-the-art of stability theory is simply stated and a typical calculation illustrated. In addition recent computer simulations of transition using the time dependent Navier-Stokes (N-S) equations are briefly described. Advances in wind tunnel capabilities and instrumentation will be reviewed followed by the presentation of a few results from both wind tunnels and flight. Finally, some suggestions for future work will complete the paper.

McDonnell Douglas Aircraft in St. Louis, MO manufacturers various transport and fighter military aircraft such as the C-17 and the F/A-18. With shrinking military budgets and increased competition, market forces demand high quality parts at lower cost and shorter lead times. Currently, a large number of different fastener types which include both solid rivets and interference bolts are used to fasten these assemblies. The majority of these fasteners are installed by hand or by using manually operated C-Frame riveters. MDA engineers recognized that in order to reach their goals they would be required to rethink all phases of the assembly system, which includes fastener selection, part fixturing and fastener installation methods. Phase 1 of this program is to identify and to develop fastener installation processes which will provide the required flexibility. The EMR fastening process provides this flexibility.

New technologies, evolving customer requirements, different process procedures, part changes, inequities between CAD model and actual fixtures and parts, and other problems all require a flexible process environment. However, increased process complexities place a burden on production operators. CIMCORP has developed a flexible environment for drilling, routing and waterjet cutting composites. The system accepts off-line CAD/CAM generated part programs, allows on-line creation and editing of programs, integrates customer expertise to help optimize production, yet maintains a simple production level environment. The environment utilizes pop-up menus and pull down interaction windows to reduce operator input to known values. An on-line RS-274 editor, communication with intelligent peripheral devices, and system administration screens for reconfiguration of process parameters are also included.

CIRA is currently designing an Unmanned Aerial Research System, featuring high structural flexibility and light weight, code named HAPD. The project is framed within the Italian Aerospace Research Program, under the “UAV” Chapter. This UAS is mainly aimed at developing and validating advanced modeling methodologies for flexible aircrafts, where structural natural frequencies may overlap with flight dynamics frequencies. This peculiar condition challenges the command and control logics, as it requires an accurate modeling of the elastic behavior of the aircraft together with an actuation policy able to guarantee that maneuvering will not result in structural modes excitation. The vehicle will be given both remote piloting functions, either fully direct or mediated by a stability and control augmentation system, and fully autonomous flight capabilities.

The BRIC-LED (Biological Research In Canisters-Light Emitting Diode) PDFU (Petri Dish Fixation Unit) apparatus was originally developed to support the on-orbit growth and subsequent fixation of any biological material amenable to petri dish culture in space. The PDFU component has been modified to support a two-stage fluid provision option so that investigations can incorporate an initial injection of a biologically active solution followed by a subsequent fixative injection to terminate the experiment in space. Crew-operated actuator tools initiate the delivery of the liquid treatments. Aseptic protocols have been developed which permit the entire experiment to be conducted under sterile conditions.

Management of technology development is a key aspect of any technology-dependent program, but at present, NASA does not manage technology development within a context of agency goals and visions spanning decades. We propose here a management framework that requires development of a technology portfolio that can be applied to achieving long term strategic goals in accordance with decade spanning vision. This process integrates program direction, maturity and time, and allows a manager to understand where to accept development risk, where to apply significant amounts of resources, and how to manage technology development as a separate element in a program.

Presented in this paper is a framework for the implementation of a robotic percussive riveting system, a new robot application for aircraft assembly. It is shown here that a successful robot application to the automation of a process requires in-depth research of the process and the interaction with the robot. For this purpose, a process planning-driven approach is proposed to guide a robot application research. A typical process planning will involve a list of key considerations including: process sequence, process parameters, process tooling, and process control. Through this list, a number of key research issues are identified for robotic percussive riveting, such as rivet pattern planning, riveting time determination, riveting tooling design and rivet insertion control. The detailed research on these issues has effectively created know-how for the successful implementation of our robotic percussive riveting system.

The influence of altitude (ambient pressure) on the auto-ignition phenomenon is a fuel property that has been studied indirectly in terms of octane-response studies involving large fleets of test vehicles. The magnitude of the measured altitude-octane response has varied from study to study and the phenomenon lacks a definitive answer. The present paper presents a simple theoretical analysis based on the response of the end-gas auto-ignition to pressure which is used to predict the altitude-octane effect. A series of tests were conducted using a standard CFR engine operating at an altitude of 1485 meters above sea-level to evaluate and confirm the theoretical findings which indicated clearly that the altitude-octane effect is an intrinsic fuel property. The magnitude of the effect was shown to vary depended on the fuel itself, but was typically in the range -1.0 to -1.5 ON/300 m for modern commercial fuels.

This AIR is a general overview of typical airborne vibration monitoring (AVM) systems with an emphasis on system hardware design considerations. It describes AVM Systems currently in use.