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The advanced inflatable airlock (AIA) system was developed for the Space Launch Initiative (SLI). The objective of the AIA system is to greatly reduce the cost associated with performing extravehicular activity (EVA) from manned launch vehicles by reducing launch weight and volume from previous hard airlock systems such as the Space Shuttle and Space Station airlocks. The AIA system builds upon previous technology from the TransHab inflatable structures project, from Space Shuttle and Space Station Airlock systems, and from terrestrial flexible structures projects. The AIA system design is required to be versatile and capable of modification to fit any platform or vehicle needing EVA capability. During the basic phase of the program, the AIA conceptual design and key features were developed to help meet the SLI program goals of reduced cost and program risk.

Spacecraft air must be treated to control the concentrations of carbon dioxide and other contaminants while also controlling oxygen concentration, humidity and temperature. These requirements in a low gravity environment currently lead to complex systems requiring substantial volume and mass. A direct liquid contact system can be used to contact recirculation air with small liquid droplets to control humidity and temperature, while managing the concentrations of carbon dioxide and other air impurities. The absorbent liquid concentration and temperature, combined with the recirculation rate can be used to independently control temperature, humidity, and carbon dioxide concentrations. The absorbent liquid is removed from the air stream using a centrifugal separator, and carbon dioxide is vented or chemically pumped to a higher pressure receiver for reuse.

The Advanced Inflatable Airlock (AIA) System is currently being developed for the 2nd Generation Reusable Launch Vehicle (RLV). The objective of the AIA System is to greatly reduce the cost associated with performing extravehicular activity (EVA) from the RLV by reducing launch weight and volume from previous hard airlock systems such as the Space Shuttle and Space Station airlocks. The AIA System builds upon previous technology from the TransHab inflatable structures project, from Space Shuttle and Space Station Airlock systems, and from terrestrial flexible structures projects. The AIA system design is required to be versatile and capable of modification to fit any platform or vehicle needing EVA capability. This paper discusses the AIA conceptual design and key features that will help meet the 2nd Generation RLV program goals of reduced cost and program risk.

A zirconia electroysis cell is an all-solid state (mainly ceramic) device consisting of two electrodes separated by a dense zirconia electrolyte. The cell electrochemically reduces carbon dioxide to oxygen and carbon monoxide at elevated temperatures (800 to 1000°C). The zirconia electrolysis cell provides a simple, lightweight, low-volume system for Mars In-Situ Resource Utilization (ISRU) applications. This paper describes the fabrication process and discusses the electrochemical performance and other properties of zirconia electrolysis cells made by the tape calendering method. Electrolytes produced by this method are very thin (micrometer-thick); the thin electrolyte reduces ohmic losses in the cell, permitting efficient operation at temperatures of 800°C or below.

In-situ production of oxygen and methane for utilization as a return propellant from Mars for both sample-return and manned missions is currently being developed by NASA in cooperation with major aerospace companies. Various technologies are being evaluated using computer modeling and analysis at the system level. An integrated system that processes the carbon dioxide in the Mars atmosphere to produce liquid propellants has been analyzed. The system is based on the Sabatier reaction that utilizes carbon dioxide and hydrogen to produce methane and water. The water is then electrolyzed to produce hydrogen and oxygen. While the hydrogen is recycled, the propellant gases are liquefied and stored for later use. The process model considers the surface conditions on Mars (temperature, pressure, composition), energy usage, and thermal integration effects on the overall system weight and size. Current mission scenarios require a system that will produce 0.7 kg of propellant a day for 500 days.

A molecular-sieve-based portable life support system (PLSS) for microgravity extravehicular activity (EVA) has been designed to minimize weight, volume, and expenditures of consumables for missions with numerous EVA's. The PLSS incorporates a regenerable two-bed molecular sieve system for CO2 and humidity removal, and a regenerable nonventing thermal sink for temperature control. The molecular-sieve-based PLSS design is modular. This approach simplifies initial manufacturing tasks, facilitates subsequent maintenance tasks, and provides the potential to tailor the PLSS to the specific environmental parameters (metabolic load, radiative environment, duration) of a given EVA excursion. This paper presents the molecular-sieve/regenerative nonventing thermal sink PLSS design and discusses the analyses and trade studies which support the design. The modular design and its benefits are discussed, and the reduced launch weight requirements of the regenerable system are quantified.