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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 paper presents the results of a CFD study for predictions of ventilation characteristics and convective heat transfer within the Shuttle Orbiter middeck cabin in the presence of seven suited crewmember simulation and Individual Cooling Units (ICU). For two ICU arrangements considered, the thermal environmental conditions directly affecting the ICU performance have been defined for landing operation. These data would allow for validation of the ICU arrangement optimization.

Estimates of the effectiveness of the high-hydrogen containing materials, sodium alanate and ammonia borane, are made by calculating dose and dose equivalent for the 1977 solar minimum and 1970 solar maximum galactic cosmic ray spectra and for the large solar particle event spectra from the space era event of August 1972 and comparing their shielding effectiveness with that of polyethylene.

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.

The Carbon Dioxide Removal Assembly (CDRA) is a part of the International Space Station (ISS) Environmental Control and Life Support (ECLS) system. The CDRA provides carbon dioxide (CO2) removal from the ISS on-orbit modules. Currently, the CDRA is the secondary removal system on the ISS, with the primary system being the Russian Vozdukh. Within the CDRA are two Desiccant/Adsorbent Beds (DAB), which perform the carbon dioxide removal function. The DAB adsorbent containment approach required improvements with respect to adsorbent containment. These improvements were implemented through a redesign program and have been implemented on units on the ground and returning from orbit. This paper presents a DAB design modification implementation description, a hardware performance comparison between the unmodified and modified DAB configurations, and a description of the modified DAB hardware implementation into the on-orbit CDRA.

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.

Protecting astronauts from space radiation exposure is an important challenge for mission design and operations for future exploration-class and long-duration missions. Crew members are exposed to sporadic solar particle events (SPEs) as well as to the continuous galactic cosmic radiation (GCR). If sufficient protection is not provided the radiation risk to crew members from SPEs could be significant. To improve exposure risk estimates and radiation protection from SPEs, detailed evaluations of radiation shielding properties are required. A model using a modern CAD tool ProE™, which is the leading engineering design platform at NASA, has been developed for this purpose. For the calculation of radiation exposure at a specific site, the cosine distribution was implemented to replicate the omnidirectional characteristic of the 4π particle flux on a surface.

There is an increasing demand in the aerospace industry for automated machinery that is portable, flexible and light. This paper will focus on a joint project between BROETJE-Automation and Boeing called the Universal Splice Machine (USM). The USM is a portable, flexible and lightweight automated drilling and fastening machine for longitudinal splices. The USM is the first machine of its kind that has the ability not only to drill holes without the need to deburr, (burrless drilling) but also to insert fasteners. The Multi Function End Effector (MFEE) runs on a rail system that is mounted directly on the fuselage using a vacuum cup system. Clamp up is achieved through the use of an advanced electromagnet. A control cart follows along next to the fuselage and includes an Automated Fastener Feeding System. This paper will show how this new advancement has the capabilities to fill gaps in aircraft production that automation has never reached before.

Excessive impact pressures can develop when an evacuated system is filled with liquid. Such a process is usually highly chaotic, especially when the system geometry is complex. Available computational methods by themselves cannot provide the necessary answers. The International Space Station (ISS) heat exchanger has a complex flow system, and a synthesis of computational and experimental methods was necessary to design the system. The FLOW-NET two-phase flow program was used to determine the range of loss coefficients and the liquid-vapor interface mass and energy transfer that would fit the measured impact pressures. These loss coefficients could then be used to compute the impact pressures for a design configuration similar to the one tested at a range of operating conditions.

A multi-element fixed control volume integrated air interchange system performance computer model has been developed and upgraded for the evaluation/assessment of atmospheric characteristics inside the crew compartments of the mated Orbiter and International Space Station (ISS). In order to ensure a safe, comfortable, and habitable environment for all the astronauts during the Orbiter/ISS docked period, this model was utilized to conduct the analysis for supporting the early ISS assembly missions. Two ISS assembly missions #2A and #4A were selected and analyzed.

The temperature and humidity of the air within the habitable areas of the International Space Station are controlled by a set of hardware and software collectively referred to as the Temperature and Humidity Control (THC) subassembly. This subassembly 1) controls the temperature of the cabin air based on a crew selected temperature, 2) maintains humidity within defined limits, and 3) generates a ventilation air flow which circulates through the cabin. This paper provides descriptions of the components of the THC subassembly, their performance ranges, and the control approach of the hardware. In addition, the solutions of the design challenges of maintaining a maximum case radiated noise level of NC 45, controlling the cabin air temperature to within ±2°F of a setpoint temperature, and providing a means of controlling microbial growth on the heat exchanger surfaces are described.

As pieces of the International Space Station (ISS) enter their test phase, access to information and data from the test laboratories must be made immediately available to analysts, managers, and customers. The Virtual Laboratory (VLAB) concept provides remote access to laboratory test data and other information, indirectly as archived data or directly as real-time data off the test bed. We applied VLAB to a life support system hardware test (the Trace Contaminant Control System, TCCS) in the Life Support Technology Center (LSTC). In this paper we describe the VLAB concept in the context of the TCCS hardware test.

International Space Station (ISS) Payload Engineering Integration (PEI) organization adopted the advanced computation and simulation technology to develop integrated electrical system models based on the test data of various sub-units. This system model was used end-to-end to mitigate system risk for the integrated Space Shuttle Pre-launch and Landing configurations. The Space Shuttle carries the Multi-Purpose Logistics Module (MPLM), a pressurize transportation carrier, and the Laboratory Freezer for ISS, a freezer rack for storage and transport of science experiments from/to the ISS, is carried inside the MPLM. An end-to-end electrical system model for Space Shuttle Pre-Launch and Landing configurations, including the MPLM and Freezer, provided vital information for integrated electrical testing and to assess Mission success. The Pre-Launch and Landing configurations have different power supplies and cables to provide the power for the MPLM and the Freezer.

The rising cost of fuel prices, in part due to the perception of diminishing supplies of common fuelstocks, as well as worldwide attention to reducing emissions has pushed the need to explore the use of many alternative fuels. The aviation industry has been under recent scrutiny due to its contribution of greenhouse gas emissions (GHG). Current contribution of GHG by airplanes is relatively small, 2% of the total GHG emissions, but world air traffic is anticipated to continue to grow and may have a corresponding increase in emissions. Both commercial and government aviation sectors have efforts to seek ways to lower fuel consumption through efficiency and reduce emissions. Development of a suitable alternative fuel that can be seamlessly used in place of conventional jet fuel is desirable. A strategy to enable this goal is to be fuel flexible; utilizing an array of fuels from bio-diesel to current jet fuel.

Modern aircraft are aerodynamically designed at the edge of flight stability and therefore require high-response-rate flight control surfaces to maintain flight safety. In addition, to minimize weight and eliminate aircraft thermal cooling requirements, the actuator systems have increased power-density and utilize high-temperature components. This coupled with the wide operating temperature regimes experienced over a mission profile may result in detrimental performance of the actuator systems. Understanding the performance capabilities and power draw requirements as a function of temperature is essential in properly sizing and optimizing an aircraft platform. Under the Air Force Research Laboratory's (AFRL's) Integrated Vehicle and Energy Technology (INVENT) Program, detailed models of high performance electromechanical actuators (HPEAS) were developed and include temperature dependent effects in the electrical and mechanical actuator components.

This paper will describe the Efficient Assembly Integration and Test (EAIT) system level project operated as a partnership among Boeing business units, universities, and suppliers. The focus is on the successful implementation and sharing of technology solutions to develop a model based, multi-product pulsed line factory of the future. The EAIT philosophy presented in this paper focuses on a collaborative environment that is tightly woven with the Lean Initiatives at Boeing's satellite development center. The prototype is comprised of a platform that includes a wireless instrumentation system, rapid bonding materials and virtual test of guidance hardware there are examples of collaborative development in collaboration with suppliers. Wireless tools and information systems are also being developed across the Boeing Company. Virtual reality development will include university partners in the US and India.

The Portable Fastener Delivery System or PFDS, has been developed at the Boeing St. Louis facility to streamline the manual fastener installation process. The PFDS delivers various fasteners, on demand, through a delivery tube to an installation tool used by the operator to install the fasteners in an aircraft assembly. This paper describes the PFDS in its current configuration, along with the associated Huck® International (now Alcoa Fastening Systems) installation tooling, as it is being implemented on the F/A-18E/F Nosebarrel Skinning application. As a “portable” system, the PFDS cart can be rolled to any location on the shop floor it might be needed. The system uses a removable storage cassette to cache many sizes and types of fasteners in the moderate quantities that might be required for a particular assembly task. The operator begins the installation sequence by calling for the particular fastener grip length needed using a wireless control pendant.

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.

The International Space Station (ISS) uses high efficiency particulate air (HEPA) filters to remove particulate matter from the cabin atmosphere. Known as Bacteria Filter Elements (BFEs), there are 13 elements deployed on board the ISS's U.S. Segment. The pre-flight service life prediction of 1 year for the BFEs is based upon performance engineering analysis of data collected during developmental testing that used a synthetic dust challenge. While this challenge is considered reasonable and conservative from a design perspective, an understanding of the actual filter loading is required to best manage the critical ISS Program resources. Thus testing was conducted on BFEs returned from the ISS to refine the service life prediction. Results from this testing and implications to ISS resource management are discussed. Recommendations for realizing significant savings to the ISS Program are presented.

The Lithium Hydroxide (LiOH) management plan to control carbon dioxide (CO2) for the Shuttle while docked to the International Space Station (ISS) reduces the mass and volume needed to be launched. For missions before Flight UF-1/STS-108, the Shuttle and ISS each removed their own CO2 during the docked time period. To control the CO2 level, the Shuttle used LiOH canisters and the ISS used the Vozdukh or the Carbon Dioxide Removal Assembly (CDRA) with the Vozdukh being the primary ISS device for CO2 removal. Analysis predicted that both the Shuttle and Station atmospheres could be controlled using the Station resources with only the Vozdukh and the CDRA. If the LiOH canisters were not needed for the CO2 control on the Shuttle during the docked periods, then the mass and volume from these LiOH canisters normally launched on the Shuttle could be replaced with other cargo.