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A baseline design has been selected for the Space Station Habitat (HAB) element. The HAB provides the primary living space to support man's permanent presence in space. The HAB element is designed to provide an environment that maximizes safety and human productivity. This paper outlines some of the current design features including the common core elements and the man-systems hardware. The HAB is arranged in three areas based on crew activity and acoustical considerations. The first area is the quiet zone, which contains the crew quarters. The second area is a buffer zone for noise suppression, where the stowage, medical facilities, and personal hygiene facilities are located. The third area is the active zone which contains the galley/wardroom, laundry and exercise facilities. Each of these three areas will be discussed together with the applicable requirements, the common utility elements, and the man-systems hardware furnishings.

Lithium-ion batteries have become prominent in many applications, because of their high energy-to-weight ratio. Unlike other types of cells, lithium-ion cells do not exhibit natural cell-to-cell balancing mechanisms. Over time, lithium-ion batteries may become unbalanced, leading to one or more cells becoming overcharged, causing cell damage. Cell balancing is required to achieve the maximum mission life for a lithium-ion battery, by reducing the possibility of overcharging or deep discharging. A BEU has been developed that uses a high-efficiency autonomous balancing circuit to maintain uniform charge on the series cells in a 24-cell battery. The balancing circuits operate continuously in all modes of operation, including charge, discharge and standby. The cell balancing currents are proportional to the voltage difference between the cells, gradually diminishing to zero as the cells achieve balance.

Affordable, reliable endo- and exoatmospheric transportation, for both the military and commercial sectors, grows in importance as the world grows smaller and space exploration and exploitation increasingly impact our daily lives. However, the impact of disciplinary, operational, and technological uncertainties inhibit the design of the requisite hypersonic vehicles, an inherently multidisciplinary and non-deterministic process. Without investigation, these components of design uncertainty undermine the designers’ decision-making confidence. In this paper, the authors propose a new probabilistic design method, using Bayesian Statistics techniques, which allows assessment of the impact of disciplinary uncertainty on the confidence in the design solution. The proposed development of a two-stage reusable launch vehicle configuration highlights the means to first quantify the fidelity of the disciplinary analysis tools utilized, then propagate such to the vehicle system level.

This paper presents an application of Bayesian Belief Networks for modeling the uncertainty in aircraft safety diagnostics. Belief networks or influence diagrams represent possible means to efficiently model uncertain causal relationships among components of a system. HUGIN is a software for the construction of knowledge based systems based on Bayesian networks. A HUGIN prototype is dicussed to illustrate how a Bayesian approach could be used to support the decision search routine of aircraft safety inspectors when diagnosing equipment of subsystem malfunctions. The example focuses on diagnostic procedures for assessing aircraft tire condition.

A low pressure axial fan for benchmarking numerical methods in the field of aerodynamics and aeroacoustics is presented. The generic fan for this benchmark is a typical fan to be used in commercial applications. The design procedure was according to the blade element theory for low solidity fans. A wide range of experimental data is available, including aerodynamic performance of the fan (fan characteristic curve), fluid mechanical quantities on the pressure and suction side from laser Doppler anemometer (LDA) measurements, wall pressure fluctuations in the gap region and sound characteristics on the suction side from sound power and microphone array measurements. The experimental setups are described in detail, as to ease reproducibility of measurement positions. This offers the opportunity of validating aerodynamic and aeroacoustic quantities, obtained from different numerical tools and procedures.

A low pressure axial fan for benchmarking numerical methods in the field of aerodynamics and aeroacoustics is presented. The generic fan for this benchmark is a typical fan to be used in commercial applications. The design procedure was according to the blade element theory for low solidity fans. A wide range of experimental data is available, including aerodynamic performance of the fan (fan characteristic curve), fluid mechanical quantities on the pressure and suction side from laser Doppler anemometer (LDA) measurements, wall pressure fluctuations in the gap region and sound characteristics on the suction side from sound power and microphone array measurements. The experimental setups are described in detail, as to ease reproducibility of measurement positions. This offers the opportunity of validating aerodynamic and aeroacoustic quantities, obtained from different numerical tools and procedures.

As space missions become longer in duration, the need to recycle waste into useful compounds rises dramatically. This problem can be addressed through the integration of human and plant modules in an ecological life support system. One of the waste streams leaving the human module is urine. In addition to the reclamation of water from urine, recovery of the nitrogen is important because it can be used as a nutrient for the plant module. A 3-step biological process for the conversion of nitrogenous waste (urea) to resource (nitrate) is proposed. Mathematical modeling was used to investigate the bioreactor system, with the goal of maximizing the ratio of performance to volume and energy requirements. Calculations show that separation of the two microbial conversions into two steps requires a smaller total reactor volume than combining them in a single bioreactor.

Bioregenerative life support systems have the potential to reduce the need for resupply from Earth for extraterrestrial habitats. The proposed advanced life support system, developed by an international and interdisciplinary team, is an innovation combination of current and near term research and technologies. The system combines physico-chemical methods with algae, aquaculture and higher plants to purify wastes and provide consumables. A closed loop percentage of 90-95% percent is expected with additional supplies for dietary supplement and maintenance. The information gained from the development of the proposed artificial biosphere can also help to solve sustainability problems currently prevalent on Earth.

Certain standard parts in the aerospace industry require qualification as a prerequisite to manufacturing, signifying that the manufacturer’s capacity to produce parts consistent with the performance specifications has been audited by a neutral third-party auditor, key customer, and/or group of customers. In at least some cases, a certifying authority provides manufacturers with certificates of qualification which they can then present to prospective customers, and/or lists qualified suppliers in a Qualified Parts List or Qualified Supplier List available from that qualification authority. If this list is in an infrequently updated and/or inconsistently styled format as might be found in a print or PDF document, potential customers wishing to integrate qualification information into their supplier tracking systems must use a potentially error-prone manual process that could lead to later reliance on out-of-date or even forged data.

Boiling heat transfer in a water heat pipe is investigated with the objective of relating heat flux and temperature drop across the evaporator. Nucleate boiling has been postulated as the heat transfer mechanism at and near the wall. A correlation has been obtained that relates evaporator heat flux and temperature drop to various screen-wick and working fluid properties. It is shown to agree well with other available experimental data.

Northrop Grumman, ASW and Ship Systems has pioneered a new thermal battery chemistry that combines high power and high energy density with multi-hour life capability. A large sonobuoy thermal battery with three hours of active life has been demonstrated and efforts are underway to extend life to four hours. Northrop Grumman believes this technology is ideally suited to weight and volume critical missile and aircraft applications. Recently, we tested a 28.5 lb., nominal 28 volt, 28 Ah battery designed to demonstrate the capability of a large thermal battery to provide prime power for missiles. Features of our thermal battery chemistry and computer design capability will be described. Performance of these large, multi-hour thermal batteries will be presented to illustrate their applicability to airborne applications.

This paper discusses various engine installations in Naval aircraft, looking especially at their costs of maintenance. Fuel systems, fuel control systems, and several engine accessories are discussed for present and future engines. It is concluded that simple, reliable equipment is necessary to keep aircraft in the air instead of in maintenance areas on the ground.

This paper describes how airplane control surface rate limiting can enable a ‘cliff-like’ onset of Pilot-Induced Oscillation, (P.I.O.) and how the danger can be erased by implementation of Conditionally Enabled Phase Compensated Rate Limiters, (PCRLs), in the design of the airplane's flight control system. The application is particularly important for large airplanes where control surface actuator sizing and the associated hydraulic system volumetric flow rate capability cannot be generously over-sized without large weight and cost penalties. It is shown that the PCRL can remain inactive during normal airplane operations where RMS control commands are relatively small thus avoiding adverse control surface response effects that have hindered earlier PCRL acceptance.

A short survey of wing tip geometries for drag reduction is presented. These devices have been divided into two broad categories of passive and active. The first category is made of fixed geometries, while the second group is made of those employing moving parts. The former group is further divided into planar and nonplanar designs. In every case, a brief explanation of the underlying logic is given. Altogether, more than fifteen completely different designs and over seventy references have been cited. Some of these designs, such as winglets, have been explored for many years and have proven to be very effective at reducing the induced drag at higher values of lift coefficient. Some others, such as wing tip turbines, have just begun to attract attention. Wing tip fuel tanks, not being solely employed for drag reduction, have not been included in this paper.

Some of the methods used for experimental detection and examination of wake vortices are presented. The aim of the article is to provide the reader a brief overview of the available methods. The material is divided into two major sections, one dealing with methods used primarily in the laboratory, and the second part devoted to those used in field operations. Over one hundred articles are cited and briefly discussed.

With reusability accepted as a means of reducing operating costs, the size of the initial investment (research and development) is likely to determine the choice for the next generation boosters. High volume utilisation lifting bodies propelled by LH/LOX rockets in a vertical take-off mode are shown to be superior to several other concepts. This is largely due to the low manufactured weight without undue complexity or use of exotic materials, leading to low R&D and low unit cost. Even lower costs can be shown for a modular concept (MUSTARD) in which basically identical lifting bodies units are utilised as both boosters and spacecraft. The concept is shown to be feasible, and progress on some aspects of the associated structural analysis is described.

Europe has embarked on a new programme of space exploration involving the development of rover, lander and probe missions to visit planets, moons and near Earth objects (NEOs) throughout the Solar System. Rovers and landers will require testing under simulated planetary, and NEO conditions to ensure their ability to land on and traverse the alien surfaces. ESA has begun work on a building project that will provide an enclosed and controlled environment for testing rover and lander functions such as landing, mobility, navigation and soil sampling. The facility will first support the European ExoMars mission due for launch in 2013. This mission will deliver a robotic rover to the Martian surface. This paper, the first of several on the project, gives an overview of its design configuration and construction phasing. Future papers will cover its applications and operations.

The business jet aircraft market continues to be a strong and growing market. Products must satisfy unique customer requirements. Significant competition in the market creates an entrepreneurial atmosphere that promotes aeronautical innovation. Examples of recent advancements are discussed. The expectation of dramatic future advances occurring within the business aircraft environment is unavoidable.

Thermal engineering has long been left out of the concurrent engineering environment dominated by CAD (computer aided design) and FEM (finite element method) software. Current tools attempt to force the thermal design process into an environment primarily created to support structural analysis, which results in inappropriate thermal models. As a result, many thermal engineers either build models “by hand” or use geometric user interfaces that are separate from and have little useful connection, if any, to CAD and FEM systems. This paper describes the development of a new thermal design environment called the Thermal Desktop. This system, while fully integrated into a neutral, low cost CAD system, and which utilitizes both FEM and FD methods, does not compromise the needs of the thermal engineer.