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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.

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.

Integrated Orbiter and International Space Station (ISS) air revitalization system performance analysis/assessment is a vital task to support the ISS assembly missions. A multi-element fixed control volume integrated air revitalization system performance computer model has been developed and upgraded for the evaluation of atmospheric characteristics inside each habitable compartments of the Orbiter and ISS. The results from this computer model were utilized to assess the interchange airflow capabilities, and to evaluate integrated air revitalization system operation limitations and requirements. Results from this performance analysis were also used to predict possible integrated air revitalization system operating constraints, such as interchange airflow rates and occupancy limitations in each module, during the ISS assembly missions. Two ISS assembly missions #2A.2b and #3A post flight data were obtained for the validation of computer model results.

Evaluation of integrated air interchange system performance is one of the important tasks in atmosphere revitalization system design to ensure a safe and habitable environment for all astronauts during the planned Orbiter and International Space Station (ISS) assembly missions. A multi-element fixed control volume integrated air interchange system performance computer model has been developed and upgraded for the evaluation of atmospheric characteristics inside all crew compartments of the Orbiter and ISS. The results from this computer model were utilized to assess and determine the Orbiter airflow supply capabilities, and to develop integrated air interchange system design limitations and requirements. Results from this performance model were also used to predict possible air interchange system operating constraints, such as occupancy limitations in each chamber, during the docked period of the missions.

Crewmember ingress of the International Space Station (ISS) before that time accorded by the original ISS assembly sequence, and thus before the ISS capability to adequately control the levels of temperature, humidity, and carbon dioxide, poses significant impacts to ISS Environmental Control and Life Support (ECLS). Among the most significant considerations necessitated by early ingress are those associated with the capability of the Shuttle Transportation System (STS) Orbiter to control the aforementioned levels, the capability of the ISS to deliver the conditioned air among the ISS elements, and the definition and distribution of crewmember metabolic heat, carbon dioxide, and water vapor. Even under the assumption that all Orbiter and ISS elements would be operating as designed, condensation control and crewmember comfort were paramount issues preceding each of the ISS Missions 2A and 2A.1.

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.

A multi-element fixed control volume air interchange system performance computer model was developed and upgraded for the evaluation of atmospheric characteristics inside each habitable volume on the mated Orbiter/Mir-Station. The results from this computer model has been utilized to assess and determine the Orbiter airflow supply capabilities, and to develop mated air interchange system design limitations and requirements. The results from this performance model were also used to predict possible air interchange system operating constraints, such as occupancy limitations in each chamber, during the Orbiter/Mir-Station docking mission. In order to verify the validity of the simulated computer model results, several post Mir missions flight data were obtained and compared.

Performance Analysis and assessment of the airflow interchange system between the mated Space Shuttle Orbiter and International Space Station (ISS) is a vital task to ensure a successful completion of the ISS assembly missions. A multi-module mated air interchange system performance computer model was developed and upgraded for evaluating the atmospheric characteristics within each habitable volume on the Orbiter and all modules of the ISS. The results from this model can be utilized to assess and determine Orbiter's interchange airflow supply capabilities, develop mated air interchange system design limitations and requirements, and predict possible mated air interchange system operating constraints during the assembly missions. The results from this performance model were also used to ensure the air interchange system operation will meet the specific environmental requirements and interface hardware design constraints.

A multi-element fixed control volume air interchange system performance computer model was developed to evaluate the atmospheric characteristics within each crew chamber on the mated Orbiter/Mir-Station/Spacelab. This computer model was utilized to analyze and determine the Orbiter airflow supply capabilities, and to develop mated air interchange system design limitations and requirements. The results from this performance model were also used to predict possible air interchange system operating constraints, such as occupancy limitations in each chamber, during the Orbiter/Mir-Station docking mission. With minor modification, this model can also be used as a predictive tool for the analysis of future International Space Station Alpha (ISSA) mated air interchange system performance during the Orbiter/ISSA docking mission.