Search Results

The Fluid Systems Servicer (FSS) is designed to drain, purge, fill, and recirculate fluids while performing on-orbit start-up, scheduled and unscheduled maintenance for fluid lines leak check ports, and window assemblies on the International Space Station (ISS). The FSS will undergo extensive functional testing to verify that all design requirements have been met. The FSS will utilize space vacuum for purging operations on-orbit, thus providing vacuum back-filling capability with minimal power consumption. For ground testing, the application of space vacuum will be simulated. A full scale mock-up of the Space Station 20″ Window Assembly has been built for requirements verification. Two desiccator assembly Orbital Replacement Units (ORU)s will be tested to assure the FSS can perform window servicing requirements. The FSS gas/liquid separator fulfills an additional design requirement of removing gas bubbles from fluids with a static membrane separator.

Regenerative processes for the revitalization of spacecraft atmospheres are required for extended duration space missions like the Space Station Freedom. A major atmosphere revitalization function is the recovery of oxygen from metabolic carbon dioxide by means of carbon dioxide reduction. The Sabatier carbon dioxide reduction technology is the baseline technology for the Space Station Freedom for this purpose. Life Systems has performed characterization and endurance testing of Sabatier reactor assemblies that has been used to design a prototype Sabatier reactor that complies with the performance requirements of the Space Station Freedom Carbon Dioxide Reduction Assembly. Information presented in the paper defines the testing that was used to design the prototype reactor and presents the successful test results that have been achieved using this reactor as part of an automated Sabatier based Carbon Reduction Assembly.

For long-duration space explorations such as the advanced manned missions to the moon and Mars, fully optimized environmental conditions and control systems are essential. This approach will not only maximize the efficiencies of the crew and other systems, but also minimize the requirements for power, weight, volume and expendables. Life Systems, working with the National Aeronautics and Space Administration-Johnson Space Center, has been investigating ways to apply various physical, chemical and electrochemical methods for this purpose. This paper presents a description of a closed ecosystem concept that includes electrochemical CO2 and O2 separators and a moisture condenser/separator for maintaining CO2, O2 and humidity levels in the crew and plant habitats at their respective optimal conditions. This concept was developed as a part of the Advanced Electrochemical CO2 Removal Process Study program sponsored by NASA-JSC.

The Static Feed Electrolyzer (SFE) has been under development by NASA through Life Systems, Inc. (Life Systems). Eighteen years of effort has characterized the SFE through extensive hours of testing, ancillary component development, and complimentary advancement in control and monitor instrumentation. The SFE technology is applicable to multiple Space Station systems, e.g., the Environmental Control and Life Support System (ECLSS), the Electric Power System (EPS), Extravehicular Activity (EVA), and the Propulsion and Reboost System. The ECLSS uses the SFE to generate metabolic oxygen (O2) for the crew, to provide reactants for carbon dioxide (CO2) removal, and to furnish hydrogen (H2) for reduction of the CO2. As part of the EPS, the SFE regenerates reactants from water to be used in producing electricity in the Regenerative Fuel Cell system (RFCS). For EVA, the SFE is used to replenish backpack and airlock O2, and regenerate the CO2 absorbent.

Progressive development of Electrochemical Carbon Dioxide (CO2) Concentration (EDC) technology by Life Systems under the sponsorship of the National Aeronautics and Space Administration (NASA) has resulted in subsystem hardware and Control and Monitor Instrumentation (C/M I) that are ideally suited for application to the Space Station program. The development effort has simplified the mechanical assembly to where only seven Orbital Replacement Units (ORUs), including two integrated components, are required to perform the process function. This simplification results in subsystem weight, power and volume requirements that are less than those of competing technologies. Further, process simplification provides both superior reliability and enhanced maintainability. Control and Monitor Instrumentation development has focused on utilization of state-of-the art electronics and software features that enhance subsystem reliability through fault detection and isolation.

The Space Station Environmental Control and Life Support System (ECLSS) consists of 51 functions. These functions are mostly independent of interactions. One exception is the regenerative air revitalization functions of carbon dioxide (CO2) removal, carbon dioxide (CO2) reduction and oxygen (O2) generation. Integration of these interdependent functions and humidity control into a single system provides significant opportunities for process simplification and reductions in power, weight and volume requirements compared to the use of discrete subsystems. An example of the magnitude of the opportunities provided is given by the ARS-1 developed by Life Systems under the sponsorship of National Aeronautics and Space Administration (NASA). Information presented in this paper quantifies the savings achieved by this integration and identifies other advantages available through process integration.

The preliminary design of the nation’s Space Station is presently being developed. The Environmental Control and Life Support System (ECLSS), consisting of regenerative and nonregenerative technologies, has progressed through a series of trade studies including evaluation of the closure and distribution within the evolutionary Space Station configuration. The analysis has included the identification of the time-critical functions, redundancy (backup) management, definition of common subsystem interfaces and quantification of technology options for the process equipment. Each technology has been characterized by its physical characteristics of weight, power, volume, heat rejection, etc. Summaries of the trade study findings for the overall ECLSS in terms of physical characteristics and the impact of selected technologies is presented.

Vapor Compression Distillation (VCD) technology for phase change recovery of potable water from wastewater has evolved as a technically mature approach for use aboard the Space Station. A program to parametrically test an advanced preprototype Vapor Compression Distillation Subsystem (VCDS) was completed by Life Systems for the National Aeronautics and Space Administration (NASA) Johnson Space Center (JSC) during 1985. In parallel with parametric testing, a hardware improvement program was initiated to incorporate and verify certain key improvements into the advanced preprototype VCDS following initial parametric tests. Specific areas of improvements included long-life, self-lubricated bearings, a lightweight, highly-efficient compressor and a long-life magnetic drive. These improvements are now incorporated and verification testing started.

The Static Feed Electrolyzer (SFE) is being developed by the National Aeronautics and Space Administration (NASA) through Life Systems, Inc. (Life Systems) as part of NASA's effort to mature water electrolysis technology for application in the Space Station Environmental Control/Life Support System (ECLSS), Propulsion and Reboost System, Extravehicular Activity (EVA) and Electric Power System (EPS). The water electrolysis process generates metabolic oxygen (O2) for the crew cabin, EVA backpacks and air lock, and provides reactants for carbon dioxide (CO2) removal, CO2 reduction, propulsion/reboost systems and fuel cell electric power generation. The use within all of these applications will make water electrolysis a fundamental utilitylike technology for the Space Station.

Regenerable carbon dioxide (CO2)/moisture removal techniques that reduce the expendables and logistics requirements are needed to sustain people undertaking extravehicular activities (EVA) for the Space Station. Life Systems, working with NASA, has been developing the Electrochemically Regenerable CO2 Absorption (ERCA) technology to replace the nonregenerable lithium hydroxide (LiOH) absorber for the, advanced Portable Life Support System (PLSS).(1) During EVA the ERCA uses a mechanism involving gas absorption into a liquid absorbent for the removal and storage of the metabolically produced CO2 and moisture. Following the EVA, the expended absorbent is regenerated on-board the Space Station by an electrochemical concept based on the Life Systems' Electrochemical CO2 Concentrator (EDC) technology. The ERCA concept has the ability to effectively satisfy the high metabolic CO2 and moisture removal requirements of PLSS applications.

There is an assortment of hardware designed to work together to provide fluid servicing, seal leak checking and other plumbing-type services on the International Space Station (ISS). The Fluid Systems Servicer (FSS) is designed to drain, purge, fill, and recirculate fluids for on-orbit start-up, scheduled and unscheduled maintenance. The FSS will utilize space vacuum for purging operations on-orbit via the Vacuum Access Jumpers (VAJ), thus providing vacuum back-filling and static leak check capability with minimal power consumption. The FSS services Internal Thermal Control Systems (ITCS) and Environmental Control & Life Support (ECLS) System hardware in the pressurized elements of the ISS. The FSS gas/liquid separator fulfills an additional design requirement of removing entrained gas from fluids by means of a static membrane separator. The FSS and some ancillary equipment also perform Seal Leak Check (SLC), pressure removal and equalization, and window assembly maintenance on ISS.