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In this study, lightning effects on hydraulic transport elements in composite aircraft have been considered for the first time. Based on recent test results and analysis, several forms of possible structural damage and system component failures are presented. A unique approach in analysis has been taken to account that hydraulic transport elements, as a part of several aircraft systems, have a common interface with electrical wiring, and become complex electric networks. When an aircraft is exposed to a direct lightning strike, a metal skin on the wings and fuselage will conduct lightning currents in a way that only a small amount of induced electromagnetic energy will be present on hydraulic transport elements. So, in the past, hydraulic tubes, actuators, manifolds, and all other hydro-mechanical devices, as parts of various aircraft systems, have never been considered as lightning sensitive components.

Future spacesuit systems for the exploration of Mars will need to be much lighter than current designs, while at the same time reducing the consumption of water for crew cooling. One of the technology paths NASA has identified to achieve these objectives is the replacement of current high pressure oxygen storage technology in extravehicular activity (EVA) systems with cryogenic technology that can simultaneously reduce the mass of tankage required for oxygen storage and enable the use of the stored oxygen as a means of cooling the EVA astronaut. During the past year NASA has funded production of a prototype system demonstrating this capability in a design that will allow the cryogenic oxygen to be used in any attitude and gravity environment. This paper describes the design and manufacture of the prototype system. The potential significance and application of the system is also discussed.

Effective thermal and micrometeoroid protection as afforded by the Thermal Micrometeoroid Garment (TMG) is critical in achieving safe and efficient missions. It is also critical that the TMG does not increase torque or decreased range of motion which can cause crewmember discomfort, fatigue, and reduced efficiency. For future exploration missions, removable and replaceable TMGs will allow the use of different pressure garment protective covers and TMG configurations for launch, re-entry, 0-G Extra Vehicular Activity (EVA), and lunar surface EVA. A study was conducted with the goal of developing high Technology Readiness Level (TRL), scalable, interface design concepts for TMG systems. The affects of TMG segmentation on mobility and donning were assessed. Closure mechanisms were investigated and tested to determine their operability after exposure to lunar dust. A TMG configuration with the optimum number of segments and location of interfaces was selected for the Mark III spacesuit.

As part of NASA's initiative to develop an advanced portable life support system (PLSS), a baseline schematic has been chosen that includes gaseous oxygen in a closed circuit ventilation configuration. Supply oxygen enters the suit at the back of the helmet, passes over the astronaut's body, and is extracted at the astronaut's wrists and ankles through the liquid cooling and ventilation garment (LCVG). The extracted gases are then treated using a rapid cycling amine (RCA) system for carbon dioxide and water removal and activated carbon for trace gas removal before being mixed with makeup oxygen and reintroduced into the helmet. Thermal control is provided by a suit water membrane evaporator (SWME). As an extension of the original schematic development, NASA evaluated several Helmet Exhalation Capture System (HECS) configurations as alternatives to the baseline.

Metabolic heat regenerated temperature swing adsorption (MTSA) technology is being developed for removal and rejection of carbon dioxide (CO2) and heat from a portable life support system (PLSS) to the Martian environment. Previously, hardware was built and tested to demonstrate using heat from simulated, dry ventilation loop gas to affect the temperature swing required to regenerate an adsorbent used for CO2 removal. New testing has been performed using a moist, simulated ventilation loop gas to demonstrate the effects of water condensing and freezing in the heat exchanger during adsorbent regeneration. Also, the impact of MTSA on PLSS design was evaluated by performing thermal balances assuming a specific PLSS architecture. Results using NASA's Extravehicular Activity System Sizing Analysis Tool (EVAS_SAT), a PLSS system evaluation tool, are presented.

The development of the Advanced Life Support (ALS) Sizing Analysis Tool (ALSSAT) using Microsoft® Excel was initiated by the Crew and Thermal Systems Division of the NASA Johnson Space Center (JSC) in 1997 to support the ALS and Exploration Offices in Environmental Control and Life Support System (ECLSS) design and studies. It aids the user in performing detailed sizing of the ECLSS for different combinations of Exploration Life Support (ELS) regenerative system technologies. This analysis tool will assist the user in performing ECLSS preliminary design and trade studies as well as system optimization efficiently and economically.

This paper summarizes the first 5 plus years of on-orbit operation for the Major Constituent Analyzer (MCA). The MCA is an essential part of the International Space Station (ISS) Environmental Control and Life Support System (ECLSS). The MCA is a mass spectrometer instrument in the US Destiny Laboratory Module of the International Space Station. The MCA provides critical monitoring of six major atmospheric constituents (nitrogen (N2), oxygen (O2), hydrogen (H2), carbon dioxide (CO2), methane (CH4) and water vapor (H2O)) sampled continuously and automatically in all United States On-Orbit Segment (USOS) modules via the Sample Distribution System (SDS). Sample lines have been routed throughout the U.S. modules with valves to facilitate software-automated sequential sampling of the atmosphere in the various modules.

A number of amine-based carbon dioxide (CO2) removal systems have been developed for atmosphere revitalization in closed loop life support systems. Most recently, Hamilton Sundstrand has developed an amine-based sorbent, designated SA9T, possessing approximately 2-fold greater capacity compared to previous formulations. This new formulation has demonstrated applicability for controlling CO2 levels within vehicles and habitats as well as during extravehicular activity (EVA). Our current data demonstrates an amine-based system volume which is competitive with existing technologies which use metal oxides (Metox) and lithium hydroxide sorbents. Further enhancements in system performance can be realized by incorporating humidity and trace contaminant control functions within an amine-based atmosphere revitalization system. A 3-year effort to develop prototype hardware capable of removing CO2, H2O, and trace contaminants from a cabin atmosphere has been initiated.

The Major Constituent Analyzer (MCA) is a mass spectrometer-based atmospheric monitoring instrument in the Laboratory Module of the International Space Station (ISS). The MCA is used for continuous environmental monitoring of 6 major gas constituents in the ISS atmosphere as well as safety-critical monitoring for special Environmental Control and Life Support (ECLS) operations such as Pre-Breathe in the Airlock for Extra-Vehicular Activities (EVAs) and oxygen re-pressurizations. For the latter, it is desirable to make most efficient use of consumables by transferring the maximum amount from O2 re-supply tanks on board the shuttle or Progress. The upper safety limit for O2 transfer is constrained by the MCA measurement error bands. A study was undertaken to tighten these error bands and afford NASA-Mission Operations Directorate (MOD) more operational flexibility.

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.

A High Heat Flux Demonstration Program has been initiated to investigate and demonstrate the performance of a number of candidate cooling technologies to address the need of dissipating the large thermal loads and high heat fluxes associated with Directed Energy Weapons (DEW) systems. The technologies selected for these investigations utilize both single-phase and two-phase cooling concepts. The single-phase devices investigated are based upon the concept of jet impingement with and without extended surface areas. The two-phase devices investigated extend the jet impingement concepts into the liquid-vapor phase change regime, as well as a device based upon vapor injection spray cooling technology. In addition, all devices must demonstrate scalability. For each device a unit cooling cell has been defined and greater surface area capability is to be achieved with the addition of adjacent cells without significantly affecting the performance of neighboring cells.

Metabolically produced carbon dioxide (CO2) removal in spacesuit applications has traditionally been accomplished utilizing non-regenerative Lithium Hydroxide (LiOH) canisters. In recent years, regenerative Metal Oxide (MetOx) has been developed to replace the Extravehicular Mobility Unity (EMU) LiOH canister for extravehicular activity (EVA) missions in micro-gravity, however, MetOx may carry a significant weight burden for potential use in future Lunar or planetary EVA exploration missions. Additionally, both of these methods of CO2 removal have a finite capacity sized for the particular mission profile. Metabolically produced water vapor removal in spacesuits has historically been accomplished by a condensing heat exchanger within the ventilation process loop of the suit life support system.

Under a NASA-sponsored technology development project, a multi-disciplinary team consisting of industry, academia, and government organizations lead by Hamilton Sundstrand is developing an amine-based humidity and CO2 removal process and prototype equipment for Vision for Space Exploration (VSE) applications. Originally this project sought to research enhanced amine formulations and incorporate a trace contaminant control capability into the sorbent. In October 2005, NASA re-directed the project team to accelerate the delivery of hardware by approximately one year and emphasize deployment on board the Crew Exploration Vehicle (CEV) as the near-term developmental goal. Preliminary performance requirements were defined based on nominal and off-nominal conditions and the design effort was initiated using the baseline amine sorbent, SA9T.

This paper presents and discusses the results of an integrated 4-Bed Molecular Sieve (4BMS), mechanical compressor, and Sabatier Engineering Development Unit (EDU) test. Testing was required to evaluate the integrated performance of these components of a closed loop atmosphere revitalization system together with a proposed compressor control algorithm. A theoretical model and numerical simulation had been used to develop the control algorithm; however, testing was necessary to verify the simulation results and further refine the model. Hardware testing of a fully integrated system also provided a better understanding of the practical inefficiencies and control issues, which are unavailable from a theoretical model.

The International Space Station Carbon Dioxide Removal Assembly (CDRA) uses regenerable adsorption technology to remove carbon dioxide (CO2) from cabin air. CO2 product water vapor measurements from a CDRA test bed unit at the NASA Marshall Space Flight Center were made using a tunable infrared diode laser differential absorption spectrometer (TILDAS) provided by NASA Glenn Research Center. The TILDAS instrument exceeded all the test specifications, including sensitivity, dynamic range, time response, and unattended operation. During the CO2 desorption phase, water vapor concentrations as low as 5 ppmv were observed near the peak of CO2 evolution, rising to levels of ∼40 ppmv at the end of a cycle. Periods of high water concentration (>100 ppmv) were detected and shown to be caused by an experimental artifact.

Hamilton Sundstrand has developed a scalable evaporative heat rejection system called the Multi-Fluid Evaporator (MFE). It was designed to support the Orion Crew Module and to support future Constellation missions. The MFE would be used from Earth sea level conditions to the vacuum of space. This system combines the functions of the Space Shuttle flash evaporator and ammonia boiler into a single compact package with improved freeze-up protection. The heat exchanger core is designed so that radial flow of the evaporant provides increasing surface area to keep the back pressure low. The multiple layer construction of the core allows for efficient scale up to the desired heat rejection rate. A full-scale unit uses multiple core sections that, combined with a novel control scheme, manage the risk of freezing the heat exchanger cores. A four-core MFE prototype was built in 2007.

Under a cooperative agreement with NASA, Hamilton Sundstrand has successfully designed, fabricated, tested and delivered three, state-of-the-art, solid amine prototype systems capable of continuous CO2 and humidity removal from a closed, habitable atmosphere. Two prototype systems (CAMRAS #1 and #2) incorporated a linear spool valve design for process flow control through the sorbent beds, with the third system (CAMRAS #3) employing a rotary valve assembly that improves system fluid interfaces and regeneration capabilities. The operational performance of CAMRAS #1 and #2 has been validated in a relevant environment, through both simulated human metabolic loads in a closed chamber and through human subject testing in a closed environment.

The Crew Exploration Vehicle (CEV), also known as Orion, will ferry a crew of up to six astronauts to the International Space Station (ISS), or a crew of up to four astronauts to the moon. The first launch of CEV is scheduled for approximately 2014. A stored water system on the CEV will supply the crew with potable water for various purposes: drinking and food rehydration, hygiene, medical needs, sublimation, and various contingency situations. The current baseline biocide for the stored water system is ionic silver, similar in composition to the biocide used to maintain quality of the water transferred from the Orbiter to the ISS and stored in Contingency Water Containers (CWCs). In the CEV water system, the ionic silver biocide is expected to be depleted from solution due to ionic silver plating onto the surfaces of the materials within the CEV water system, thus negating its effectiveness as a biocide.

In future lunar and Mars exploration missions the ability to provide the crewmember navigation information will be critical. Exploration demands that Extravehicular Activity (EVA) astronauts be provided the capability to operate with greater autonomy in accomplishing complex EVA missions than has been the case previously. Robust crew information interfaces and navigation support integral to the EVA spacesuit system are expected to be minimum requirements. Navigation support must allow the EVA crew to determine their position relative to EVA target locations, satellite imagery and maps and assist them in walking or riding to the desired targets on the planetary surface. Together, these needs suggest a requirement for an integrated system that combines data and voice communications, a high performance visual display, and navigation support in a design that is compatible with spacesuit environmental and packaging restrictions and with unique EVA crew interface demands.

Advanced water processors being developed for NASA's Exploration Initiative rely on phase change technologies and/or biological processes as the primary means of water reclamation. As a result of the phase change, volatile compounds will also be transported into the distillate product stream. The catalytic reactor assembly used in the International Space Station (ISS) water processor assembly, referred to as Volatile Removal Assembly (VRA), has demonstrated high efficiency oxidation of many of these volatile contaminants, such as low molecular weight alcohols and acetic acid, and is considered a viable post treatment system for all advanced water processors. To support this investigation, two ersatz solutions were defined to be used for further evaluation of the VRA. The first solution was developed as part of an internal research and development project at Hamilton Sundstrand (HS), and is based primarily on ISS experience related to the development of the VRA.