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Aerospace applications with requirements for large capacity heat removal (launch vehicles, platforms, payloads, etc.) typically use a liquid coolant as a thermal transport media to increase efficiency and flexibility in vehicle design. An issue with these systems, however, is susceptibility to the presence of non-condensable gas (NCG) or air. The presence of air in a coolant loop can have one or more negative consequences. It can cause loss of centrifugal pump prime, interfere with sensor readings, inhibit heat transfer, and block coolant flow to remote systems. Hardware ground processing to remove this air is also cumbersome and time consuming which drives up these recurring costs. Current systems for maintaining the system free of air are tailored and have demonstrated only moderate success.

The efficiency of re-useable aerospace systems requires a focus on the total operations process rather than just orbital performance. For the Multi-Purpose Logistics Module, this activity included special attention to terrestrial conditions both pre-launch and post-landing and how they inter-relate to the mission profile. Several of the efficiencies implemented by the MPLM Mission Engineering Team were NASA firsts and all served to improve the overall operations. This paper provides the integrated engineering/operations solutions to several key issues. Topics range from statistical analysis of over 30 years of atmospheric data at the launch and landing site to a new approach for operations with the Shuttle Carrier Aircraft. In each situation, the goal was to “tune” the thermal management of the overall flight system for minimizing requirement risk while optimizing power and energy performance.

Hamilton Sundstrand Space Systems International (HSSSI) is currently under contract with NASA MSFC to design, fabricate and deliver the Water Processor Assembly (WPA) for the International Space Station (ISS). As part of this effort HSSSI has developed an oxidation catalyst for the catalytic reactor assembly in the WPA. This paper discusses full-scale development reactor testing and the status of the life testing of the oxidation catalyst used in the reactor.

A work envelope has been defined for weightless Extravehicular Activity (EVA) based on the Space Shuttle Extravehicular Mobility Unit (EMU), but there is no equivalent for planetary operations. The weightless work envelope is essential for planning all EVA tasks because it determines the location of removable parts, making sure they are within reach and visibility of the suited crew member. In addition, using the envelope positions the structural hard points for foot restraints that allow placing both hands on the job and provides a load path for reacting forces. EVA operations are always constrained by time. Tasks are carefully planned to ensure the crew has enough breathing oxygen, cooling water, and battery power. Planning first involves computers using a virtual work envelope to model tasks, next suited crew members in a simulated environment refine the tasks.

The Crew Exploration Vehicle (CEV) is the first crew transport vehicle to be developed by the National Aeronautics and Space Administration (NASA) in the last thirty years. The CEV is being developed to transport the crew safely from the Earth to the International Space Station and then later, from the Earth to the Moon . This year, the vehicle continued to go through design refinements to reduce weight, meet requirements, and operate reliably while preparing for Preliminary Design Review in the summer of 2009. The design of the Orion Environmental Control and Life Support (ECLS) system, which includes the life support and active thermal control systems, is progressing through the design stage. This paper covers the Orion ECLS development from April 2008 to April 2009.

NASA, Marshall Space Flight Center (MSFC) is developing a Urine Processor Assembly (UPA) for the International Space Station (ISS). The UPA uses Vapor Compression Distillation (VCD) technology to reclaim water from pre-treated urine. This water is further processed by the Water Processor Assembly (WPA) to potable quality standards for use on the ISS. NASA has developed this technology over the last 25-30 years. Over this history, many technical issues were solved with thousands of hours of ground testing that demonstrate the ability of the UPA technology to reclaim water from urine. In recent years, NASA MSFC has been responsible for taking the UPA technology to “flight design” maturity. This paper will give a brief overview of the UPA design and a status of the major design and development efforts completed recently to mature the UPA to a flight level.

In NASA's Vision for Space Exploration, humans will once again travel beyond the confines of earth's gravity, this time to remain there for extended periods. These forays will place unprecedented demands on launch systems. They must not only blast out of earth's gravity well as during the Apollo moon missions, but also launch the supplies needed to sustain a larger crew over much longer periods. Thus all spacecraft systems, including those for the separation of metabolic carbon dioxide and water from a crewed vehicle, must be minimized with respect to mass, power, and volume. Emphasis is also placed on system robustness both to minimize replacement parts and ensure crew safety when a quick return to earth is not possible. This paper describes efforts to improve on typical packed beds of sorbent pellets by making use of structured sorbents and alternate bed configurations to improve system efficiency and reliability.

The International Space Station (ISS) Environmental Control and Life Support (ECLS) system includes regenerative and non-regenerative technologies that provide the basic life support functions to support the crew, while maintaining a safe and habitable shirtsleeve environment. This paper provides a summary of the U.S. ECLS system activities over the past year, covering the period of time between May 2001 and April 2002. The ISS continued permanent crew operations, with Phase 2 completion accomplished during this period. Work continued on the Phase 3 elements with Node 3 proceeding toward a final design review and the regenerative ECLS equipment proceeding into manufacturing.

The International Space Station (ISS) Node 3 includes a substantial amount of equipment to support a variety of Environmental Control and Life Support System (ECLSS) functions. This includes a combination of equipment items that are common with ECLSS equipment distributed throughout other ISS pressurized elements and other equipment that is unique to Node 3. Common equipment provides non-regenerative ECLS functions of atmosphere control and supply (ACS), temperature and humidity control (THC), fire detection and suppression (FDS), and waste management (WM) for Node 3 and/or attached elements. Additional equipment provides air revitalization (AR) and water recovery and management (WRM) functions that are necessary for station-level redundancy, but in a manner that allows for the minimization of life support logistics burdens.

The International Space Station (ISS) United States Orbital Segment (USOS) Oxygen Generation System (OGS) was originally intended to be installed in ISS Node 3. The OGS rack delivery was accelerated, and it was launched to ISS in July of 2006 and installed in the US Laboratory Module. Various modification kits were installed to provide its interfaces, and the OGS was first activated in July of 2007 for 15 hours. In October of 2007 it was again activated for 76 hours with varied production rates and day/night cycling. Operational time in each instance was limited by the quantity of feedwater in a Payload Water Reservoir (PWR) bag. Feedwater will be provided by PWR bag until the USOS Water Recovery System (WRS) is delivered to ISS in fall of 2008. This paper will discuss operating experience and characteristics of the OGS, as well as operational issues and their resolution.

The Mini-Pressurized Logistics Module (MPLM), shown in Figure 1, is the primary vehicle for the transportation of equipment, scientific payloads, and supplies for use inside of the International Space Station, hence the importance of the MPLM environmental control system design. Agenzia Spaziale Italian (ASI), an International Space Station Partner (IP), will supply three MPLMs, currently being designed and fabricated by Alenia Aerospazio, Divisione Spazio, to the Space Station Program. Design oversight for this activity is being performed by NASA's Marshall Space Flight Center (MSFC).

The Multi-Purpose Logistics Module (MPLM) is the primary carrier for “pressurized” logistics to and from the International Space Station (ISS). The MPLM is transported in the payload bay of the Space Shuttle and is docked to the ISS for unloading, and reloading, of contents within the ISS shirt sleeve environment. Foil heaters, controlled originally with bi-metallic thermostats, are distributed across the outside of the MPLM structure and are utilized to provide energy to the structure to avoid exposure to cold temperatures and prevent condensation. The existing bi-metallic, fixed temperature set point thermostats have been replaced with Programmable Thermostats Modules (PTMs) in the Passive Thermal Control Subsystem (PTCS) 28Vdc shell heater circuits. The goal of using the PTM thermostat is to improve operational efficiency of the MPLM on-orbit shell heaters by providing better shell temperature control via feedback control capability.

NASA's Marshall Space Flight Center is providing three racks containing regenerative water recovery and oxygen generation systems (WRS and OGS) for flight on the International Space Station's (ISS) Node 3 element. The major assemblies included in these racks are the Water Processor Assembly (WPA), Urine Processor Assembly (UPA), Oxygen Generation Assembly (OGA), and the Power Supply Module (PSM) supporting the OGA. The WPA and OGA are provided by Hamilton Sundstrand Space Systems International (HSSSI), while the UPA and PSM are being designed and manufactured in-house by MSFC. The assemblies are completing the manufacturing phase and are in various stages of ORU and system level testing, to be followed by integration into the flight racks. This paper gives a current status, along with technical challenges encountered and lessons learned.

NASA is completing the development of a regenerative water recovery system (WRS) for the International Space Station (ISS). The major assemblies included in this system are the Water Processor Assembly (WPA) and Urine Processor Assembly (UPA). Test activities have been completed for the system and planning for launch and on-orbit activation is underway. This paper summarizes the status as of April 2008 and describes some of the technical challenges encountered and lessons learned over the past year.

NASA is developing a regenerative water recovery system (WRS) for deployment on the International Space Station (ISS). The major assemblies included in this system are the Water Processor Assembly (WPA) and Urine Processor Assembly (UPA). The WPA has been developed by Hamilton Sundstrand Space Systems International (HSSSI), Inc., while the UPA has been developed by the Marshall Space Flight Center (MSFC). Test and verification activities have been completed for the system and planning for launch and on-orbit activation is underway. This paper summarizes the status as of April 2007 and describes some of the technical challenges encountered and lessons learned over the past year.