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There are a large number of space structures, orbital replacement units (ORUs) and other components that must be transported to orbit on a regular basis for the assembly and maintenance of the International Space Station (ISS). Some of this hardware will be ferried on the Spacelab Logistics Pallet (SLP), which has a long and reliable history of space flight successes. The carrier is well used, well qualified, and very adaptable for repeated use in accommodating cargoes of various sizes and shapes. This paper presents an overview of past, present and future hardware design solutions that accommodate EVA operations on the SLP. It further demonstrates how analysis techniques and design considerations have influenced the hardware development, EVA operations, and compliance with human engineering requirements for the SLP.

A review of the current extended-range twin-engine operations (ETOPS) and the modifications to the standards and processes that led to its successful operational record has contributed to the feasibility of developing an airplane and preparing an operator for ETOPS at entry into service. The airplane and engine manufacturers and component suppliers have continued to expand on these modified standards and processes in their design, build, test and support programs to meet regulatory authority ETOPS requirements and to facilitate the development of regulatory authority criteria for substantiating ETOPS capability prior to entry into service. Airlines, in conjunction with the manufacturers, have also developed improved processes that meet regulatory authority requirements for preparing an operator to integrate a new airplane into its existing ETOPS programs at entry into service.

This paper reviews the recent G189A computer program developments in the area of humidity control for the U.S. Lab Module in the Space Station. The humidity control function is provided as an indirect or passive function by the Common Cabin Air Assemblies (CCAA) in pressurized elements or modules in the Space Station. The CCAAs provide active cabin temperature control through implementation of a digital/electromechanical control system (i.e., a proportional/integral (PI) control system). A selected cabin temperature can be achieved by this control system as long as the sensible and latent heat loads are within specified limits. In this paper three pertinent analytical cases directed to determining minimum or maximum dew point temperatures are discussed. In these cases the basic sensible heat loads are set at constant values.

A new process has been developed to cold work fastener holes on commercial aircraft flap tracks fabricated of 4340M steel. The process consists of pressing a high strength solid mandrel through a previously prepared hole in a defined manner. This process exhibits high tool life, low overall cost and eliminates the necessity for a final ream operation.

A considerable amount of integrated Environmental Control and Life Support System (ECLSS) analysis has been performed and documented for the proposed habitable Space Station. Earlier analytic activities have resulted in highly refined models simulating Temperature and Humidity Control (THC) and Atmosphere Revitalization (AR) hardware. As the mechanisms by which these items affect the Space Station environment have become better understood (along with the effects due to operation of various Man Systems utilities), the next stage of the integrated analysis task has been accomplished; i.e., the simulation of the Atmosphere Control and Supply (ACS) subsystem. The focus of the present paper is upon the ACS function in the overall life support system. Modeling of the ACS is unique among the life support disciplines in that it requires accurate representation of all other ECLSS subsystems that interact with the cabin atmosphere (which has now been achieved) in order to be realistic.

Fastener selection entails two functions, a staff function to select a group of fasteners for consideration and a design function to select the most suitable fastener for a specific function. This paper itemizes in detail the considerations that enter into each function in selecting fasteners for commercial and military aircraft, military unmanned vehicles, and space vehicles. Characteristics of specific bolts and fasteners are also tabulated.

The key results of a NASA-sponsored study of a large multipurpose launch concept are summarized. The study evolved, through parametric performance and detailed design analyses, the characteristics of an attractive launch vehicle approach for consideration in future mission planning studies. The reported vehicle system has only two stages: a LOX/LH2 main stage and a solid-motor strap-on stage. The main stage has the performance capability to fly single-stage-to-orbit and the structural capability to accommodate strap-on stages to achieve a broad range of payload flexibility. The salient features of the vehicle system, sized to deliver one to four million pounds to low earth orbit, are described. The major resource and technology implications of the system are discussed.

An overview of composite structure required for manned orbiting space stations is presented. Following a brief introduction of typical configurations and major subsystems, the major structural areas requiring composite structure and their particular functions and requirements are discussed. A summary weight breakdown is presented to assess the dependence of launch weight on these areas. To illustrate, the primary wall composite structure is presented in detail. The design interplay of boost, pressure, meteoroid, radiation, and thermal control requirements are presented. Resultant composite structure for each remaining major structural area is presented in summary form with a brief description of typical design compromises required.

Space Station Freedom (SSF) has an extended mission duration of 30 years. Trade studies for extended missions of manned spacecraft almost invariably show that large resupply weight and consequent cost savings can be achieved by recovering potable water from wastewater sources. This rationale has led to the present baseline Water Recovery and Management (WRM) system for the Permanently Manned Capability (PMC) phase of SSF. The baseline WRM includes the Vapor Compression Distillation (VCD) subsystem for recovering water from urine. This process serves as a preliminary processing step in achieving potable water from wastewater sources. The basic principle of the VCD is that water is evaporated from urine and then condensed in a zero-gravity device containing an evaporator and a condenser in a rotating drum. The VCD was selected for the baseline WRM following the assessment of test results from competitive urine processing subsystems obtained from the Comparative Test (CT) program.

During a recent International Space Station (ISS) flight (Flight 2A.1), an improper ventilation event might have occurred and resulted in stuffy air, as reported by the crew. Even though no air samples were analyzed, the accumulation of metabolic CO2 in the ISS was suspected as the cause of the crew sickness. With no possibility of conducting an on-orbit test of this kind, it was decided to utilize Computational Fluid Dynamics (CFD) analysis to investigate this problem. Based on the Flight 2A.1 and 2A.2a configurations, a CFD model of the air distribution system was built to characterize airflow between the ISS elements. This model consists of Inter-module Ventilation (IMV) covering the Functional Cargo Block (FGB), two Pressurized Mating Adapters (PMA-1 and PMA-2), the Node-1, and portions of the Orbiter volume.

Flight testing of aircraft under natural icing conditions can be extremely tedious, time consuming, costly, and somewhat risky. However, such testing has been required to demonstrate the effectiveness of anti-icing systems and to certify new aircraft models. To reduce the need for extensive flight testing, Boeing has built a new icing tunnel that has the capability for developing ice shapes and evaluating anti-icing features on full scale sections of critical parts of the aircraft. The icing tunnel was made by modifying an existing 5 ft by 8 ft Boeing Wind Tunnel to add icing capabilities. This paper describes the design specifications, the tunnel capabilities, and the major equipment systems and presents the results of the tunnel calibration relative to the specified requirements.

Assembly techniques for the majority of expendable and reusable launch vehicles have not changed much over the last thirty years. Some progress has been made, specifically on new programs, however, improvements on existing expendable launch vehicle production lines can be difficult to justify; even more so for one or two reusable vehicles. This presentation will focus on techniques and systems used for manual and automated assembly of expendable and reusable launch vehicle primary structures. Today's assembly is characterized by manual operations involving fixtures and templates, and all tasks are carried out primarily with single function hand tools. Typical assembly approaches used for metallic and composite primary structures will be discussed. Potential opportunities for process improvements utilizing advanced hand tools, mechanized and/or automated equipment will be addressed.

Recent applications of numerical optimization to the design of advanced airfoils for transonic aircraft have shown that low-drag sections can be developed for a given design Mach number without an accompanying drag increase at lower Mach numbers. This is achieved by imposing a constraint on the drag coefficient at an off-design Mach number while the drag at the design Mach number is the objective function. Such a procedure doubles the computation time over that for single design-point problems, but the final result is worth the increased cost of computation. The ability to treat such multiple design-point problems by numerical optimization has been enhanced by the development of improved airfoil shape functions. Such functions permit a considerable increase in the range of profiles attainable during the optimization process.

Since the advent of the turbojet engine, there has been much research by aircraft and engine manufacturers into the source of aircraft noise and its reduction. A review of this research is presented delineating the transition from turbojet engines to turbofan engines to the high by-pass ratio engines being introduced today, and the progress that has been made. Application of the current state-of-the-art to existing airplanes through engine replacement, nacelle retrofit, and flight procedures are also discussed.

The new 757/767 transports will be the first Boeing Commercial aircraft to commit advanced graphite composite material to initial production. Composite materials, mainly fiberglass in an epoxy matrix, have been used in Boeing military and commercial aircraft in ever increasing amounts for the past twenty (plus) years. Recently, the state-of-the-art of Advanced Composites (graphite and graphite/Kevlar hybrids in an epoxy matrix) progressed to the level that it could be committed to full-scale production. This production commitment resulted in a multi-year, multi-million dollar development program. This was to assure technical and production readiness, and product reliability to meet the stringent performance and safety standards of modern commercial transport.

The joint development of an augmentor wing jet STOL research aircraft by NASA and the Canadian Government Department of Industry, Trade, and Commerce has progressed to the point that the design of the modifications to the de Havilland C-8A Buffalo are complete and the engines are being tested. The predicted performance shows that the airplane will be able to take off and land in less than 1500 ft. Simulation studies indicate that the handling qualities of the airplane, with stability augmentation, will be acceptable for STOL research missions.

Results are presented of a preliminary study into the major factors which affect the design of spacecraft for manned explorations of Mars. Two basic manned missions are considered, Mars orbiting and Mars landing. For the latter, two modes are considered, Mars orbital rendezvous with landing to be accomplished by an excursion vehicle detached from the parent orbiting spacecraft, and direct landing in which the entire spacecraft is landed on Mars. System weights are presented for these modes in terms of number of men in the crew, trip time, and stay time on Mars. Considerations are made of the types of life support and propulsion systems used. Major problem areas are identified.

Understanding the friction behavior of brake lining materials is fundamental to the ability to predict brake system performance. Of particular interest to the aviation community, where carbon/carbon composite heatsinks are commonly used, is the aircraft response at deceleration onset. There are two performance measures defining brake system performance at braking onset: deceleration onset rate and system response time. The latter is strictly a function of the brake system hydraulics and is not affected by brake lining friction. The former performance measure is a function of both system hydraulics and brake lining friction. Previously to the work herein, carbon heatsink friction was thought to be unpredictable at braking onset. That being the case, a predictive capability for deceleration onset rate was not previously undertaken. This meant that assessment of this performance measure waited until aircraft taxi tests were performed.

This paper concerns a new technique designed to provide high performance reaction control systems for sounding rockets. Proportional control of differential thrust and simple adaptive control of thrust magnitude (based on the level of demanded thrust) is utilized. The control is being implemented with a combination of electronic and fluidic components for an Aerobee 150 sounding rocket payload whose goal is a pointing stability of 0.1 arc second.

This paper addresses the three questions: “Is V/STOL capability economically viable for business aircraft, and if so, how does the viability depend on the aircraft concept?”; “How is a V/STOL concept chosen to match a given mission, and what are some of the promising V/STOL concepts for future business aircraft?”; and “What unique operational requirements are likely to be imposed on users of future V/STOL business aircraft?” A cost-benefit analysis is presented which indicates that a VTOL business aircraft would be more viable economically than a contemporary turbine-powered business aircraft. The combinations of traveler's time value and trip distance for which each aircraft dominates is shown. A discussion is presented on the significance of disc loading as it relates to V/STOL concept application. Preliminary design configuration studies for three different business-aircraft-sized V/STOLs, using three concepts covering a range of disc loading, are presented as examples.