Search Results

Carbon dioxide removal from the Space Station Freedom atmosphere is an essential part of crew life support. Freedom must utilize carbon dioxide removal systems to prevent crew asphyxiation. This paper describes the predevelopment operational system test (POST) four-bed molecular sieve carbon dioxide removal assembly, its operation, and its key components. Many approaches are available to effect carbon dioxide removal, and include both regenerative and non-regenerative methods. To minimize Freedom logistics support and to close the cabin oxygen loop, regenerative systems will be relied upon. The Freedom carbon dioxide removal assembly will selectively remove carbon dioxide from an air supply stream, preventing carbon dioxide accumulation within the cabin, and then concentrate it for downstream processing in a carbon dioxide reduction system where oxygen eventually is recovered. Freedom will utilize a regenerative four-bed molecular sieve system for the carbon dioxide removal assembly.

Boeing is responsible for Space Station Freedom (Work Package (WP) 01) which includes the Habitat and U.S. Laboratory modules, which includes the integration of the Environmental Control and Life Support System (ECLSS). Included as part of the ECLSS is the Atmosphere Revitalization (AR) subsystem. The AR subsystem provides for removal of metabolic carbon dioxide, removal of trace contaminants, and continuous monitoring of the cabin atmosphere major constituent composition during the Manned Tended Configuration (MTC) phase of station operations. The focus of this paper is on the Carbon Dioxide Removal Assembly (CDRA) flight design aspects of the Space Station Freedom (SSF) AR subsystem. A Four Bed Molecular Sieve (4BMS) has been selected by Boeing as the CDRA for SSF. The CDRA removes carbon dioxide from an air slip stream pulled from the Cabin Air Temperature & Humidity Control (THC) assembly.

Carbon dioxide removal from the Space Station Freedom atmosphere is an essential part of the overail life support and oxygen reclamation process. The system must selectively remove carbon dioxide from an air supply stream, then concentrate it for downstream processing in a carbon dioxide reduction system where oxygen is eventually recovered. Space Station Freedom will utilize a four-bed molecular sieve system for the carbon dioxide removal assembly. This system uses the principle of adsorption to selectively remove and concentrate carbon dioxide. The technology required for the four-bed system is well established and was proven in space flight during the Skylab program. This paper describes the four-bed molecular sieve carbon dioxide removal system, its operation and its key components.

The carbon dioxide removal assembly (CDRA) is an essential part of the International Space Station (ISS) environmental control and life support system. As such, this system is required to selectively remove carbon dioxide from the cabin atmosphere, and discharge it overboard to space vacuum. Verification of the many CDRA requirements is divided into analysis, demonstration, inspection, and test methods. This paper focuses on the results of protoflight performance testing conducted on the first deliverable CDRA. The results of this performance testing indicated that the CDRA design exceeded all of the performance requirements.

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.

Logistical costs associated with replenishing the International Space Station (ISS) with oxygen can be reduced by closing the air revitalization process loop. The carbon dioxide removal assembly (CDRA) is a part of this air revitalization process, and would require only minimal alteration to effect closed-loop operation. Closed-loop CDRA operation entails interfacing the existing open-loop CDRA configuration to a downstream carbon dioxide reduction system. This interface's requirement is to store and to maintain carbon dioxide feed to the downstream reduction system. Many approaches are available to effect closed-loop CDRA operation, and one economical method is the utilization of its existing 2-stage air-save pump and companion motor controller designs. This paper focuses on the closed-loop CDRA operational control methods and performance analysis, which utilizes design of experiment tools to optimize the CDRA control parameters.