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In part two of a two-part series, Richard Gardner discusses various aerospace propulsion innovations and continued work by aerospace engineers and scientists to advance aircraft engine technologies to increase efficiency and lower emissions.

Catalytic combustion coupled with activated carbon and molecular sieve adsorbents is applicable to all areas of air and gas clean up ranging from high to low levels of pollutants and trace contaminants control in a spacecraft environment is of no exception. In this study we propose a combined activated charcoal and catalytic combustion system based on a 70 watt power input achieving 350°C, operating on a 6 hour per 24 hour day catalytic cycle with an actual flow of 10.6 l min-1 in a residual free volume of 60 m3.

Trends towards lower vehicle fuel consumption and smaller environmental impact will increase the share of Diesel hybrids and Diesel Range Extended Vehicles (REV). Because of the Diesel engine presence and the ever tightening soot particle emissions, these vehicles will still require soot particle emissions control systems. Ceramic wall-flow monoliths are currently the key players in the Diesel Particulate Filter (DPF) market, offering certain advantages compared to other DPF technologies such as the metal based DPFs. The latter had, in the past, issues with respect to filtration efficiency, available filtration area and, sometimes, their manufacturing cost, the latter factor making them less attractive for most of the conventional Diesel engine powered vehicles. Nevertheless, metal substrate DPFs may find a better position in vehicles like Diesel hybrids and REVs in which high instant power consumption is readily offered enabling electrical filter regeneration.

This paper describes the development of a packaging technique using the new dual in-line package. Part one tells why this package was developed and gives some advantages this technique has over present trends in packaging. Part two gives a complete explanation and description of the component parts of the package. The third part elaborates on the heart of the package, namely the interconnection matrix. Details are given on converting from a systems logic diagram to a graphic format used in the development of the matrix layout. Part four explains the step by step procedure used in manufacturing the dual in-line module on both the prototype and production level. The fifth and final part of the paper tells of other packaging techniques using as a basic building block, the internal parts of the dual in-line module.

For the removal of NOx from the oxygen-rich diesel exhaust in mobile applications the selective catalytic reduction (SCR) is one of the most favored technologies. Well established NH₃-SCR technique uses either V₂O₅/WO₃-TiO₂ or Zeolite-based catalysts, NOx being continuously reduced by NH₃ resulting in the selective formation of nitrogen and water. A major drawback of V₂O₅-based formulations is their lower thermal stability and low temperature activity, in addition, V₂O₅ release poses serious environmental and toxicity problems. In active filter regeneration performed by post-injection of fuel the temperature may increase up to 800°C resulting in drastic loss of activity (due to poor stability of V₂O₅-based formulations) as well as discharge of V₂O₅.

As electronic components and circuits get smaller the problems of mounting and interconnecting elements into a system become more difficult. This paper indicates how one packaging concept using a carrier-mother board, rack approach, interconnected by wire-wrap techniques solves some of the problems imposed by these small components. Flexibility, cost, reliability and their influence on the selection of the final configuration are investigated. The application of hot gas soldering for mounting flat packs to carriers is described along with the advantages gained by its use.

Pyrolysis processing is one of several options for solid waste resource recovery in space. It has the advantage of being relatively simple and adaptable to a wide variety of feedstocks and it can produce several usable products from typical waste streams. The objective of this study is to produce a prototype mixed solid waste pyrolyzer for spacecraft applications. A two-stage reactor system was developed which can process about 1 kg of waste per cycle. The reactor includes a pyrolysis chamber where the waste is heated to temperatures above 600°C for primary pyrolysis. The volatile products (liquids, gases) are transported by a N2 purge gas to a second chamber which contains a catalyst bed for cracking the tars at temperatures of about 1000 °C −1100 °C. The tars are cracked into carbon and additional gases. Most of the carbon is subsequently gasified by oxygenated volatiles (CO2, H2O) from the first stage.

The Regenerable Trace Contaminant Control System (RTCCS) is a system designed to meet all of the size, weight, power use, contaminant removal rate, and operational requirements of the International Space Station (ISS) Trace Contaminant Control Subassembly (TCCS) without the need to replace an approximately 80 lb charcoal bed every 90 days. It is designed to remove every class of contaminants found in spacecraft cabin air, including alcohols, aldehydes, aromatics, ethers, esters, chlorocarbons, halocarbons, fluorosilanes, hydrocarbons, ketones, silicones, sulfides, and inorganics, and it is designed to operate continuously with minimal maintenance or periodic replacement major components. The RTCCS is comprised primarily of a pre-sorbent bed, regenerable bed, catalyst bed subassembly, post sorbent bed, blower, and associated valves and instruments.

A review of the progress in the aeronautical and aerospace spares management which has occurred roughly from the mid 1940's through 1963. Areas covered include Commercial Airline, Army, Navy, Air Force and NASA. It includes some of the past history of spares management and improvements gained. The paper covers, in each of the above areas, the range of spares management from provisioning, ordering, inventory control and distribution through packaging and handling. Progress has been considerable over the past 20 years, and it is anticipated that more efficient spares management is imminent as refinements and improvements are continued.

The British Royal Navy has no method for removing Carbon Monoxide (CO) from a Disabled Submarine (DISSUB) when the air revitalisation, circulation and monitoring system is shutdown. There is a specific requirement to produce a portable low temperature CO removal unit that does not require power from the submarine. CO levels could rise due to a fire or a leak in the Diesel Generator compartment. A number of incidents have shown that CO concentrations can rise above the Maximum Permissible Concentration 60 minutes continuous period (MPC60) in a short time. This study was compiled from a literature review of commercially available products, methods and techniques and catalysts that are mainly still in development. The system will be required to function in a DISSUB situation and to support the current high temperature catalytic method of CO removal, when needed. Each technique's potential for application has been investigated for this paper.

Currently, proposed water recovery systems for baseline space missions consist of integrated technologies to remove contaminants from graywater for reuse. Lacking in these mission scenarios and in current research efforts is a solid understanding of how photocatalysis might perform as a primary and/or secondary processor. However, one of the major hurdles for slurry-based photocatalysis is the ability to separate the catalyst from solution after mineralization of pollutants is complete. Purifics, a Canadian engineering company, has solved this problem with a patented separation device utilizing a backpressure cycled membrane and automated system (Photo-Cat®). Purifics specifically designed a pilot unit to be used to solve the water recovery problem for long-term space missions. Operating Purifics’ Photo-Cat® as a secondary processor, with and without ammonium bicarbonate demonstrated that the TOC concentration could be reduced to below 0.5 ppm.

Nuclear submarines may remain at sea submerged for weeks or months at a time and a range of equipment is provided aboard to purify and re-vitalise the air in order to maintain a viable atmosphere for the crew to breathe over extended periods. Activated carbon beds are used to remove ppm-level organic contaminants that build up in the atmosphere from, for example, lubricants and the outgassing of materials of construction. These carbon beds require frequent replacement and present a substantial logistic demand. The beds also constitute an increased fire hazard as the amount of adsorbed material builds up. Photocatalysis is a process whereby a semiconductor catalyst material, typically titanium dioxide (TiO2), is irradiated in air with ultraviolet (UV) light. This produces high-energy hydroxyl radicals that are capable of completely oxidising a range of molecules to simple, relatively non-toxic, species. For instance, hydrocarbons are generally oxidised to water and carbon dioxide.

The kinetics of the Sabatier methanation reaction, the reduction of carbon dioxide with hydrogen to methane and water, was investigated for 58 percent nickel on kieselguhr catalyst and 20 percent ruthenium on alumina catalyst. Differential rate data from an experimental program were correlated with a power function rate equation both for forward and reverse reactions. The kinetic parameters of activation energy, frequency rate constant and reaction order were determined for the rate equation. The values of these parameters were obtained from an Arrhenius plot of the experimental differential rate data. Also the carbon monoxide side reaction effect was measured and included in the correlation of parameters. The reaction was found to fit the rate equation experimentally within the temperature range 421°K, where the reaction effectively begins, to 800°K where the reaction rate drops and departs from the rate equation form.

The Cassini spacecraft, NASA's mission to investigate the Saturn system, has undergone a system-level thermal balance test program to permit verification of the engineering subsystem thermal designs in the simulated worst-case environments. Additionally, other objectives such as functional checkouts, collection of thermal data for analytical model adjustment, vacuum drying of propellant tanks, and flight temperature transducer verification were also completed. In the interest of cost and schedule, transient off-Sunpoint conditions were not tested. The testing demonstrated that the required system resources such as heater power and radiator area were adequate for all engineering subsystems. The only changes required from the results were related to the operation of some of the subsystems. In the instance of the thruster cluster assemblies, allowable flight temperature limits were exceeded for the assumed operational environment.

A series of experiments to evaluate performance of catalysts for CELSS System Wet-oxidation process has been carried out. Data obtained from the experiments show that the noble metal selected for the catalyst gives a good performance in oxidizing Organic Carbon and Organic Nitrogen. The data also show that a catalyst with certain amount of the metal (wt%) shows maximum efficiency in the oxidation; in addition, a catalyst with a different amount of metal gives good performance in producing high quality fertilizer.

The Advanced Animal Habitat (AAH) represents the next generation of Space Station based animal research facilities. Building upon previously developed flight hardware and experience, the AAH offers greatly enhanced system capabilities and performance. The design focuses upon the creation of a robust and flexible platform capable of supporting present and future experimental needs. A modular packaging and distributed control architecture leads to increased system adaptability and expandability. The baseline configuration includes group housing capability for up to six rats with automated food and water delivery as well as waste collection. Animals are continuously monitored with three cameras during both day and night cycles. The animals can be accessed while on-orbit through the Life Sciences Glovebox to perform a wide variety of experimental protocols.

This specification covers a two-component compound, an epoxy resin base and a hardener in the form of a paste.