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The orbit maneuvering engines provide the propulsive thrust to increase or decrease the velocity of the space shuttle orbiter while in earth orbit. The design and operational philosophy of the shuttle vehicle and orbital maneuvering system are discussed along with the design characteristic and selection rational for the current baseline orbit maneuvering system. The need for long life and economic reusability are the new shuttle requirements which must be considered along with traditional factors such as performance, reliability, and weight. Critical development issues and potential alternate designs are also discussed.

The need for increased maneuverability has its genesis from the first aerial combat engagement when two adversaries entangled themselves in a deadly aerial dance trying to gain the advantage over the other. It has only been in the past two decades that technologies have been investigated to increase aircraft control at maneuver attitudes that are typically dominated by highly separated flows. These separated flow regions are aggravated by advanced fighter aircraft shapes required to defeat an electronic enemy. This paper discusses passive and active devices that can be used to enhance the maneuverability of advanced fighter aircraft through vortex flow control, boundary layer control, and innovative flow manipulation.

Missions envisioned for micro air vehicles may require a high degree of autonomy to operate in unknown environments. As such, vision is a critical technology for mission capability. This paper discusses an autopilot that uses vision coupled with GPS and altitude sensors. One use of vision processing analyzes a horizon to estimate roll and pitch information. Another use tracks a feature point to estimate position relative to a target. This paper presents examples of waypoint navigation and homing using vision-based feedback. The examples indicate the vision provides sufficient information to achieve the missions.

A manganese fuel additive, MMT, is now being used in many unleaded gasolines to improve their octane quality. Use of MMT at concentrations up to 0.033 g Mn/ℓ (0.125 g Mn/gal) is expected to increase. To determine the effect of MMT on exhaust emission control systems, five cars were tested for 80 000 km (50,000 miles) using a driving schedule which included 113 km/h (70 mph) steady speed driving. In this type of operation, use of MMT caused: plugging of monolithic converters located close to the exhaust manifold; partial plugging of an underfloor bead converter; an increase of hydrocarbon emissions from the engines; and excessive spark plug deposits. However, use of MMT apparently enhanced catalytic converter oxidizing activity and did not substantially affect octane requirement increase. These preliminary data suggest that use of MMT in commercial gasolines may cause problems with exhaust emission control systems now in use.

A test program was conducted with a carbureted 2.3-liter engine in which a map of engine operating conditions over which intake manifold wall films of appreciable magnitude exist was defined on the basis of visual observations. It was found that the largest maldistributions of fuel/air ratio among the four cylinders of the engine occurred during operation at conditions characterized by the presence of extensive fuel puddles on the intake manifold floor. However, it was also found that while the intake manifold fuel films and puddles could essentially be eliminated by heating the manifold floor, the fuel/air ratio distributions among cylinders under such conditions were virtually identical to those measured under conventional operating conditions.

The effect of an active flow control method is investigated on a 1:4 scale realistic vehicle model called “DrivAer” with notchback geometry. The wind tunnel experiments are conducted at a Reynolds number of Re=3.0·106. Fluidic oscillators are applied at the c-pillars and at the upper rear edge of the window. The actuators are installed inside the hollow designed model emitting a high frequency sweeping jet. The spacing of the actuators, the mass flow rate, and the position of actuation are varied. The effect of the active flow control on the car is investigated with force and surface pressure measurements. The surface trace pattern is visualized with tufts for the active flow control cases and the baseline case. A tuft algorithm analyzes provides statistical data of the flow angles. Moreover, particle image velocimetry measurements are performed in the plane of symmetry for β=0° to capture the flow field at the rear end and the wake.

Many remotely controlled manipulative devices have been designed and operated successfully for extended periods in nuclear, industrial, underwater, underseas, high temperature, inert gas, hard vacuum, space, explosive, corrosive, toxic, and other hazardous environments. This paper describes the environmental protection for typical manipulative devices and discusses design parameters, methods of operation, design features, materials of construction, and, where possible, operating experience to date.

IN 1900, old experienced engine builders were saying “impossible” to an 18 to 22 lb per hp ratio for an engine which was being designed for use in the man-carrying flying machine under development by Dr. S. P. Langley, Secretary of the Smithsonian Institution. By December, 1901, working as Dr. Langley's chief assistant - and having taken personal responsibility for the engine development - Charles Matthews Manly had completed an engine which weighed, net 125 lb, developed 52.4 hp at 950 rpm and had demonstrated its durability in three separate 10-hr full-power endurance runs. This 2.4 lb per hp ratio was not surpassed until the advent of the Liberty engine 16 years later. Dramatic details of this most frequently recorded achievement of the distinguished engineer who was SAE president in 1919 are recorded in this paper as part of an interpretive study of Mr. Manly's broad achievements. Mr.

Partial preliminary designs are presented for two manned - automatic structural assembly systems. Consideration is given to structural sectionalizing, fasteners, structural assembly mechanisms, kinematics, and program logic. The employment of man to enhance system performance is considered.

The 60-Day and 90-Day closed manned chamber tests conducted by the McDonnell Douglas Corporation in the 1960s have been thoroughly reported in the literature. These tests evaluated, among other things, the leading water recycling systems developed at that time. During both tests, crew members ingested water reclaimed from urine and humidity condensate and performed personal hygiene tasks with water recycled in a separate loop. Since then, to this date (1995), no comparable testing has been carried out in the United States. Now, however, plans are being made to test modern water recycling systems in chamber tests with humans. This paper summarizes the earlier testing and highlights the lessons that were learned.

Previous violent controversies concerning the value of manned versus unmanned space exploration are being resolved to a significant degree. Improved understanding of man's role in space exploration and more effective means of utilizing man as a part of “automatic,” “remotely controlled,” and “directly manned” space exploration systems are evolving. The advocates of both manned and unmanned space exploration are making progress in a direction providing mutual support. As a result, an overall increase in the rate and effectiveness of the gathering of knowledge from space is likely. This paper describes current developments.

Man’s knowledge of outer space far surpasses his knowledge of the oceans’ depths, but the development of functional submersibles has provided new pathways to factual information of suboceanic phenomena. These vehicles afford many advantages over remote controlled devices, as this paper points out. However, experience has proved that adequate investigation can be accomplished only by manned vehicles, utilizing trained operators in situ and the uncomparable observational capability of the human eye.

Design requirements and operational constraints are reviewed for a small manually controlled flying vehicle which could provide astronauts with mobility for lunar exploration. Numerous flight trajectories and the vehicle performance have been analyzed and are presented. It is concluded that to attain the desired flight ranges, the flight velocities must be relatively high (200 fps or more). The range of thrust level required is determined. Flyer configuration is highly dependent on the method of control (either mechanical engine gimballing or kinesthetic control); the optimum method is still unresolved.

In the overall planning of a manned mission to Mars, all the issues related to human involvement are critical. To a certain extent, they dictate the most severe constraints on the mission scenario and spacecraft architecture. Despite this unanimously recognized importance, limited efforts have been devoted up to now to dedicated research activities on human-related aspects, partially neglected w.r.t. more technical areas like orbital dynamics, propulsion, power generation, etc. This paper summarizes the major results of a survey on the human factors of long duration missions performed by Alenia Spazio in the frame of an ESA study, MARSEMSI, whose aim was to identify possible scenarios and related infrastructure requirements for a manned mission to Mars.

The introduction of the Space Transportation System provides opportunities for improved space operations, reliability and cost effectiveness by taking advantage of man's presence. The astronaut with the proper machines can augment the Shuttle to an extent that tasks never performed in space, such as maintenance and repair of satellites and the construction of large structures can now be done. This paper addresses an evolution of one of these machines, the Manned Remote Work Station (MRWS). The MRWS is a series of EVA platforms and crew cabins that perform roles which are common on the ground such as cherry pickers, crane turrets, emergency repair vehicles and short haul transporters. Concepts and their space applications will be delineated for near term applications in support of the Space Shuttle and future applications in support of the Space Station.

A rationale will be presented,as to why a lunar base should be the next logical step of a future scenario for manned space flight preceding a flight to Mars. In this respect, the lunar base and the Mars flight examples and their life support systems will be addressed. An overview of past experiences, especially Apollo, and the current knowledge is given concerning both lunar missions and life support systems. Also, critical areas of mission design and preparation, like the necessity of precursor missions, the potential of resource utilization, radiation shielding, and life support system evolution, are addressed. This paper decribes a general development scenario for future manned missions to the Moon and Mars and why a “dress rehearsal” of a mission to Mars in the Earth-Moon-system will be necessary, and what lessons can be learned from the development of a lunar base for missions to Mars.

A description is given of a computer program developed at the National Aeronautics and Space Administration (NASA) Langley Research Center (LaRC) for the assessment of manned space station environmental control and life support systems (ECLSS) technology. The program methodology along with the data base and mission model variables are given for 17 candidate technologies that show potential for supplying metabolic oxygen and water on manned space missions. The data base includes metabolic design loads associated with crew activity, engineering design parameters for each technology option, and cost data required for candidate life cycle cost comparisons. The method for ranking the candidate options in order to provide recommendations for space station application or subsequent development is presented.

The large difference between the total numbers of manned and unmanned spacecraft and their respective missions is discussed. The environmental and functional requirements having different effects on the two spacecraft types are described. The materials characteristics involved in those requirements and the resulting typical configurations are reviewed. It is concluded that vibration and pressurized gas containment have the outstanding influence on spacecraft structural systems. It is noted that new structural factors of safety have not been derived on the basis of any rational consideration of the design conditions for stability or pressure critical structure.

The Manpower, Personnel, and Training (MPT) in Acquisition Decision Support System (DSS) is an Air Force program providing the first integrated tool for addressing MPT requirements during system acquisition and design. New weapon system development and major modifications have historically neglected how our most important and costly resource - people - will maintain and support the fielded system. Inadequate planning for training and deploying the human element has often delayed system operational dates. This DSS will assist acquisition managers and analysts to effectively integrate people issues (numbers, characteristics, proficiency) with equipment (aircraft) early in the acquisition cycle. Acquisition specialists can use the structured analysis approach provided by the MPT DSS to ensure that system people costs are affordable, jobs are properly structured, and people are trained prior to the system becoming operational.

Due to an increase in spacecraft traffic forecasted for the space station era, researchers are investigating manual control and other aspects of docking operations with hopes of increasing safety, productivity, and likelihood of success while decreasing cost. Experiments have been performed which revealed the effect of approach velocity, in-flight anomalies, and control mode. Displays have been designed to enable flight planners to more easily overcome the difficulties presented by orbital mechanics. Improved understanding of human factors in the docking mission and other orbital maneuvers will play a significant role in design tradeoffs concerning thruster size, docking fixture style and mass, and on-board trajectory planning displays.