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Since the 1960's, lightning protection of aircraft has been an important design aspect, a concern for the flying public, aircraft manufacturers and the Federal Aviation Administration (FAA). With the implementation of major aircraft structures fabricated from carbon fiber reinforced plastic (CFRP) materials, lightning protection has become a more complicated issue to solve. One widely used material for lightning strike protection of CFRP structures within the aerospace industry is expanded metal foil (EMF). EMF is currently used in both military and commercial passenger aircraft. An issue that has historically been an area of concern with EMF is micro cracking of paint on the composite structure which can result in corrosion of the metal foil and subsequent loss of conductivity. This paper addresses the issues of stress and displacement in the composite structure layup which contribute to paint cracking caused by aircraft thermal cycling.

The technology selected for waste processing has a major effect on system closure and mission equivalent system mass (ESM). In particular, recovery of the water content of solid waste can make the difference between a mission being water poor and water rich. Potential alternative sources of water that need to be considered would include recovery of water from carbon dioxide reduction, and in situ resources. This paper looks at a range of waste-processing scenarios and calculated system ESM impacts related to these options. The lowest ESM approach is generally storage or dumping. However, other issues also need to be considered. Processing may be driven by requirements such as the need to recover commodities like water, prevent release of toxic gases into the spacecraft environment, planetary protection requirements, and interface loads.

Clothing can constitute a major logistical problem for advanced missions. Current and historical clothing systems for space missions have been assessed, as has the viability of using a washing machine to clean (recycle) clothing. Modern fabrics can reduce the mass and increase the functionality of clothing, including reducing the risk of fire, for all missions. The increased cost of acquisition of even high tech commercial off the shelf (COTS) items is trivial compared to the cost of shipping the clothing and disposing of it as trash. Washing can be cost effective when water is recycled efficiently, provided the mission is long enough. The breakeven time for clothes-washing depends on the specifics of the mission, particularly the mass equivalencies of infrastructure, but is of the order of weeks rather than years.

One of the most critical functions of ECLSS is to maintain the atmospheric oxygen concentration within habitable limits. On the ISS, this function is provided by the Major Constituent Analyzer (MCA). During ISS (International Space Station) crew increments 7 thru 9, the MCA was at risk of imminent failure as evident by sustained high ion-pump current levels. In the absence of continuous constituent measurement by the MCA, manual methods of estimating partial pressure of oxygen (ppO2) and concentration levels need to be developed and validated to: (1) ensure environmental control and life support, (2) prohibit ISS system and hardware damage, and (3) enable planned ISS activities that effect constituent balance.

Increased nickel concentrations in the IATCS coolant prompted a study of the corrosion rates of nickel-brazed heat exchangers in the system. The testing has shown that corrosion is occurring in a silicon-rich intermetallic phase in the braze filler of coldplates and heat exchangers as the result of a decrease in the coolant pH brought about by cabin carbon dioxide permeation through polymeric flexhoses. Similar corrosion is occurring in the EMU de-ionized water loop. Certain heat exchangers and coldplates have more silicon-rich phase because of their manufacturing method, and those units produce more nickel corrosion product. Silver biocide additions did not induce pitting corrosion at silver precipitate sites.

The Internal Thermal Control System (ITCS) has been developed jointly by Boeing Corporation, Huntsville, Alabama and Honeywell Engines & Systems, Torrance, California to meet the internal thermal control needs for the International Space Station (ISS). The ITCS provides heat removal for the critical life support systems and thermal conditioning for numerous experiment racks. The ITCS will be fitted on a number of modules on the ISS. The first US Element containing the ITCS, Node 1, was launched in December 1998. Since Node 1 does not contain a pump to circulate the fluid it was not filled with ITCS fluid until after the US Laboratory Module was installed. The second US Element module, US Laboratory Module, which contains the pumps and all the major ITCS control hardware, was launched in February 2001. The third US Element containing the ITCS, the US Airlock, was launched in July 2001.

Clothing accounts for a surprisingly large quantity of resupply and waste on the International Space Station (ISS), of the order of 14% of the equivalent system mass (ESM). Efforts are underway in the ISS program to reduce this, but much greater changes are likely to be possible and justifiable for long duration missions beyond low Earth orbit (LEO). Two approaches are being assessed for long duration missions: to reduce the mass of the wardrobe through use of lighter fabrics, and to clean clothing on board for reuse. Through good design including use of modern fabrics, a lighter weight wardrobe is expected to be feasible. Collateral benefits should include greater user comfort and reduced lint generation. A wide variety of approaches to cleaning is possible. The initial evaluation was made based on a terrestrial water-based washer and dryer system, as this represents the greatest experience base.

The International Space Station (ISS) will be the largest structure ever built in space. Differences between ISS and previous NASA vehicles led to developing new labeling methods, conventions and material. The challenge was to provide clear and meaningful identification, location, operations and safety information for the crews who will assemble, maintain and live onboard ISS.

Work defining advanced life support (ALS) technologies and evaluating their applicability to various long-duration missions has continued. Time-dependent and time-invariant costs have been estimated for a variety of life support technology options, including International Space Station (ISS) environmental control and life support systems (ECLSS) technologies and improved options under development by the ALS Project. These advanced options include physicochemical (PC) and bioregenerative (BIO) technologies, and may in the future include in-situ-resource utilization (ISRU) in an attempt to reduce both logistics costs and dependence on supply from Earth. PC and bioregenerative technologies both provide possibilities for reducing mission equivalent system mass (ESM). PC technologies are most advantageous for missions of up to several years in length, while bioregenerative options are most appropriate for longer missions. ISRU can be synergistic with both PC and bioregenerative options.

The significant problem of engine power-loss and damage associated with ice crystal icing (ICI) was first formally recognized by the industry in a 2006 publication [1]. Engine events described by the study included: engine surge, stall, flameout, rollback, and compressor damage; which were triggered by the ingestion of ice crystals in high concentrations generated by deep, moist convection. Since 2003, when ICI engine events were first identified, Boeing has carefully analyzed event conditions documenting detailed pilot reports and compiling weather analyses into a database. The database provides valuable information to characterize environments associated with engine events. It provides boundary conditions, exposure times, and severity to researchers investigating the ICI phenomenon. Ultimately, this research will aid in the development of engine tests and ICI detection/avoidance devices or techniques.