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Fabrication and assembly of the majority of control surfaces for Boeing’s 777X airplane is completed at the Boeing Defense, Space and Security (BDS) site in St. Louis, Missouri. The former 777 airplane has been revamped to compete with affordability goals and contentious markets requiring cost-effective production technologies with high maturity and reliability. With tens of thousands of fasteners per shipset, the tasks of drilling, countersinking, hole inspection, and temporary fastener installation are automated. Additionally and wherever possible, blueprint fasteners are automatically installed. Initial production is supported by four (4) Electroimpact robotic systems embedded into a pulse-line production system requiring strategic processing and safeguarding solutions to manage several key layout, build and product flow constraints.

Both humans and onboard radiosensitive systems (electronics, materials, payloads and experiments) are exposed to the deleterious effects of the harsh space radiations found in the space environment. The purpose of this paper is to present the space radiation environment extended to deep space based on environment models for the moon, Mars, Jupiter, and Saturn and compare these radiation environments with the earth's radiation environment, which is used as a comparative baseline. The space radiation environment consists of high-energy protons and electrons that are magnetically “trapped” in planetary bodies that have an intrinsic magnetic field; this is the case for earth, Jupiter, and Saturn (the moon and Mars do not have a magnetic field). For the earth this region is called the “Van Allen belts,” and models of both the trapped protons (AP-8 model) and electrons (AE-8 model) have been developed.

Solar proton events (SPEs) represent the single-most significant source of acute radiation exposure during space missions. Historically, an exponential in rigidity (particle momentum) fit has been used to express the SPE energy spectrum using GOES data up to 100 MeV. More recently, researchers have found that a Weibull fit better represents the energy spectrum up to 1000 MeV (1 GeV). In addition, the availability of SPE data extending up to several GeV has been incorporated in analyses to obtain a more complete and accurate energy spectrum representation. In this paper we discuss the major SPEs that have occurred over the past five solar cycles (~50+ years) in detail - in particular, Aug 1972 and Sept & Oct 1989 SPEs. Using a high-energy particle transport/dose code, radiation exposure estimates are presented for various thicknesses of aluminum. The effects on humans and spacecraft systems are also discussed in detail.

A dual-membrane gas trap is currently used to remove gas bubbles from the Internal Thermal Control System (ITCS) coolant on board the International Space Station (ISS). The gas trap consists of concentric tube membrane pairs, comprised of outer hydrophilic tubes and inner hydrophobic fibers. Liquid coolant passes through the outer hydrophilic membrane, which traps the gas bubbles. The inner hydrophobic fiber allows the trapped gas bubbles to pass through and vent to the ambient atmosphere in the cabin. The gas trap was designed to last for the entire lifetime of the ISS, and therefore was not designed to be repaired. However, repair of these gas traps is now a necessity due to contamination from the on-orbit ITCS fluid and other sources on the ground as well as a limited supply of flight gas traps. This paper describes a novel repair technique that has been developed that will allow the refurbishment of contaminated gas traps and their return to flight use.

This paper identifies an approach to the definition of a National Airspace System (NAS) architecture which will support the future development of the U.S. air transportation system, consistent with long-range needs of the various users of the NAS. The approach outlined identifies the development of an FAA preliminary design methodology, with supporting tools and processes to provide the basis for NAS modernization. This approach begins with the quantification of the primary long-range objectives of the NAS, which the system architecture must support over its design life. These objectives are the basis of the mission analysis and requirements development, which, in turn, are used for technology tradeoff studies and the baselining of an architecture for evaluation.

A study was conducted to investigate the impacts of obstacles on pilot performance, workload, and perceptions of safety in a visual flight rule (VFR) obstacle-rich environment (ORE). The study was conducted using a piloted simulation of a single-rotor, multi-engine helicopter operating in a highly detailed urban visual scene database. The database contained multiple obstacle types, with variable obstacle heights and densities. Nine pilots completed the approaches and departures into and out of a heliport located in the center of the generic urban environment. Two flight routes offered unique presentations of terrain and obstacle types. Obstacle height/density and time of day/lighting parameters were systematically manipulated. A multi-dimensional data collection methodology employing the simultaneous collection of direct aircraft state, pilot performance data, pilot physiological data and pilot subjective responses was employed.

The characteristics of the friction materials used in aircraft brakes are extremely important to the performance and safe operation of transport airplanes. These characteristics can change during exposure to environmental effects in the duty cycle, which can lead to problems, such as abnormally low friction, or brake induced vibration. Water vapor in the atmosphere produces a direct lubricant effect on carbon. Observed transition temperatures within the range of 140°C to 200°C, associated with increases in friction and wear of carbon brake materials, are attributed to water vapor desorption. Friction and wear transitions in the range of 500°C to 900°C may be associated with oxygen desorption.

Crew health is dependent on the concentration of carbon dioxide in the atmosphere breathed. Often, models used for concentration have used the assumption that each module of the space station is well mixed, i.e. that the CO2 concentration is constant throughout the module. In this paper, Computational Fluid Dynamics (CFD) modeling is used to assess and validate the accuracy of that assumption. The concentration of carbon dioxide as calculated by CFD was compared to the concentration as calculated by a lumped parameter model. The assumption that the module is well mixed allows the use of relatively simple models, which can be developed and run quickly in order to support decisions for on-orbit analysis. CFD models generate more detailed information, such as CO2 gradients within the modules and airflow and mixing characteristics. However, CFD models, particularly transient models, take longer to develop and use.

An air quality simulation and assessment (AQSA) model was developed to simulate/evaluate the integrated system performance and obtain air quality characteristics and air contaminants inside the habitable compartments. This model applies both fixed control volume and quasi-steady-state approach for a multi-volume system to assess system performance, operating constraints, and capabilities. The model also integrates a state-of-the-art probabilistic analysis tool, UNIPASS, to compute failure probability due to the uncertainties of variables. In addition, this integrated model also predicts the most likely outcomes for analyzing risks and uncertainties as well as for quantitative toxicological evaluation. This model has been successfully and independently corrected/verified by NASA/JSC to be a very effective, reliable, and accurate tool, while providing savings in both the cost and time of the analysis.

Currently scheduled to be delivered to the International Space Station (ISS) in 2009, Crew Quarters (CQs) will be installed in the Node 2 Module. The CQs provide crewmembers with private space, a place to sleep, and minimal storage. Analysis is to be performed to determine if the United States Operational Segment (USOS) Node 2 can maintain temperature between 47°C and 62°C (65°F and 80°F) [units are CCGS with U.S unit in parenthesis] within the CQ. The analysis will concentrate on the nominal hot environmental case. Environmental heat is due to solar heating of the external shell of the ISS. Configurations including both three and four CQs are examined, as well as multiple configurations of the Low Temperature Loop (LTL) that flows through the Node 2 Common Cabin Air Assembly (CCAA). This paper describes the analysis performed to determine if Node 2 will be able to maintain cabin temperature between 47°C and 62°C (65°F and 85°F).

This paper presents results of the CFD study aimed at evaluation of the CO2 concentration within the Shuttle Orbiter Middeck during the Launch on Need (LON) Crew Rescue flight. An assessment of the Middeck ventilation characteristics has been performed for two possible ventilation arrangements. A recommendation to use the ventilation system configuration with the open aft floor diffuser has been made on the basis of a three-dimensional airflow and CO2 gradient analysis.

Recent efforts have been pursued to establish the usefulness of Space Shuttle Orbiter lithium hydroxide (LiOH) canisters beyond their certified two-year shelf life, at which time they are currently considered “expired.” A stockpile of Orbiter LiOH canisters are stowed on the International Space Station (ISS) as a backup system for maintaining ISS carbon dioxide Canisters with older (CO2) control. Canister with older pack dates must routinely be replaced with newly packed canisters off-loaded from the Orbiter Middeck. Since conservation of upmass is critical for every mission, the minimization of canister swap-out rate is paramount. LiOH samples from canisters with expired dates that had been returned from the ISS were tested for CO2 removal performance at the NASA Johnson Space Center (JSC) Crew and Thermal Systems Division (CTSD). Through this test series and subsequent analysis, performance degradation was established.

An ongoing effort is underway at NASA Ames Research Center (ARC) to develop an On-line Project Information System (OPIS) for the Advanced Life Support (ALS) Program. The objective of this three-year project is to develop, test, revise and deploy OPIS to enhance the quality of decision-making metrics and attainment of Program goals through improved knowledge sharing. OPIS will centrally locate detailed project information solicited from investigators on an annual basis and make it readily accessible by the ALS Community via a Web-accessible interface. The data will be stored in an object-oriented relational database (created in MySQL®) located on a secure server at NASA ARC. OPIS will simultaneously serve several functions, including being an research and technology development (R&TD) status information hub that can potentially serve as the primary annual reporting mechanism for ALS-funded projects.

In order to conserve mass and volume, it was proposed that the International Space Station (ISS) control the level of carbon dioxide (CO2) in the Space Shuttle Orbiter while the Orbiter is docked to the ISS. If successful, this would greatly reduce the number of lithium hydroxide (LiOH) canisters required for each ISS-related Orbiter mission. Because of the impact on the Orbiter Environmental Control and Life Support Subsystem (ECLSS), as well as on the Orbiter flight manifest, a Space Shuttle Program (SSP) analysis was necessary. STS-108 (ISS UF1) pre-flight analysis using the Personal Computer Thermal Analyzer Program (PCTAP) predicted that the ISS would be able to control the level of CO2 in the Orbiter (and throughout the stack) under nominal conditions with no supplemental LiOH required. This analysis assumed that the Carbon Dioxide Removal Assembly (CDRA) located in the U.S.

In August 1997 NASA/Marshall Space Flight Center (MSFC) began a test with the objective of monitoring the growth of microorganisms on material simulating the surface of the International Space Station (ISS) Temperature and Humidity Control (THC) Condensing Heat Exchanger (CHX). The test addressed the concerns of potential uncontrolled microbial growth on the surface of the THC CHX subsystem. For this study, humidity condensate from a closed manned environment was used as a direct challenge to the surfaces of six cascades in a test set-up. The condensate was collected using a Shuttle-type CHX within the MSFC End-Use Equipment Testing Facility. Panels in four of the six cascades tested were coated with the ISS CHX silver impregnated hydrophilic coating. The remaining two cascade panels were coated with the hydrophilic coating without the antimicrobial component, silver. Results of the fourteen-month study are discussed in this paper.

The OVERFLOW chimera grid Navier Stokes code was used to analyze a wide variety of airplane configurations. The code performed reliably and was found to have comparable accuracy to the structured grid code TLNS3D. It is easier to develop overlapping grid blocks to represent a complex configuration than it is to develop grid blocks that must abut one another. The process is inherently modular. One can add or subtract components like tip-lights, compound winglets, struts, nacelles, tails and fairings at will. The gain in grid simplicity is offset by the complication in specifying block connectivity, however. The overset blocks are typically of better quality, but there is a drawback in that it is not always possible to guarantee flux conservation. The recent development of software for automatic connectivity holds promise for the routine use of OVERFLOW by design engineers.

The aircraft asset life cycle processes are rapidly being digitalized. Many novel technologies enabled processes of recording these electronic transactions are being emerged. One such technology for recording electronic transactions securely is Blockchain, defined as distributed ledger technologies which includes enterprise blockchain. Blockchain is not widely used in the aerospace industry due to lack of technical understanding and questions about its benefits. Assessment and establishment of business case for implementing blockchain based solution is needed. The aerospace industry is very conservative when it comes to technology adoption and hence it is difficult to change legacy processes. Additionally, the industry is very fragmented. The technology is advancing at a faster rate and applies across geographies under various regulatory oversight which makes blockchain based solution implementation challenging.

The objective of this study is to evaluate ventilation efficiency regarding to the International Space Station (ISS) cabin ventilation during the ISS assembly mission 1J. The focus is on carbon dioxide spatial/temporal variations within the Node 2 and attached modules. An integrated model for CO2 transport analysis that combines 3D CFD modeling with the lumped parameter approach has been implemented. CO2 scrubbing from the air by means of two ISS removal systems is taken into account. It has been established that the ventilation scheme with an ISS Node 2 bypass duct reduces short-circuiting effects and provides less CO2 gradients when the Space Shuttle Orbiter is docked to the ISS. This configuration results in reduced CO2 level within the ISS cabin.

The Centrifuge Accommodation Module (CAM) is designed to be one of the modules of the International Space Station (ISS) for performing on-orbit science experiments over an extended period of time. The common cabin air assembly (CCAA) is utilized as the hardware for air temperature and humidity control (THC) for the CAM module cabin. The CCAA unit contains a variable speed fan, heat exchanger, temperature control valve, water separator, temperature sensor, and electrical interface box. A temperature and humidity simulation model was developed to perform the THC analysis for the CCAA unit inside the CAM. This model applies both fixed control volume and a quasi-steady-state approach for computing critical information for evaluating/assessing CCAA system performance and capabilities.

After launch and activation activities, the Columbus module started its operational life on February 2008 providing resources to the internal and external experiments. In March 2008 two US Payloads were successfully installed into Columbus Module: Microgravity Sciences Glovebox (MSG) and a US payload of the Express rack family, Express Rack 3, carrying the European Modular Cultivation System (EMCS) experiment. They were delivered to the European laboratory from the US laboratory and followed few months later by similar racks; Human Research Facility 1 (HRF1) and HRF2. The following paper provides an overview of US Payloads, giving their main features and experiments run inside Columbus on year 2008. Flight issues, mainly on the hydraulic side are also discussed. Engineering evaluations released to the flight control team, telemetry data, and relevant mathematical models predictions are described providing a background material for the adopted work-around solutions.