William R. Humphries

Past and Present Environmental Control and Life Support Systems on Manned Spacecraft

The spacecraft environmental control and life support systems (ECLSS) for Mercury, Gemini, Apollo, Skylab, Spacelab, the Space Shuttle Orbiter, and Space Station Freedom are reviewed, in addition to the ECLSS on Soviet spacecraft Vostok, Voskhod, Soyuz, Salyut Space Stations, the Buran Space Shuttle, and the Mir Space Station. Focus is placed on atmosphere control and supply, atmosphere revitalization, potable and supply water systems, waste-management systems, temperature and humidity control, water recovery and management, and fire detection and suppression. It is noted that the ECLSS evolution will continue during the lifetime of Space Station Freedom, leading to further simplifications and closure of the system which will become a controlled ecological life support system (CELSS).

Environmental control and life support testing at the Marshall Space Flight Center

The Space Station Environmental Control and Life Support System (ECLSS) test program at the Marshall Space Flight Center (MSFC) is addressed. The immediate goals and current activities of the test program are discussed. Also described are the Core Module Integration Facility (CMIF) and the initial ECLSS test configuration. Future plans for the ECLSS test program and the CMIF are summarized.

Preliminary Design of the Space Station Environmental Control and Life Support System

This paper outlines the current status of the Space Station Enrivonmental Control and Life Support System (ECLSS). The seven subsystem groups which comprise the ECLSS are identified and their functional descriptions are provided. The impact that the nominal and safe haven operating requirements have on the physical distribution, sizing, and number of ECLSS subsystems is described. The role that the major ECLSS interfaces with other Space Station systems and elements play in the ECLSS design is described.

Technology demonstrator program for Space Station Environmental Control Life Support System

The main objectives and requirements of the NASA/Marshall Space Flight Center Technology Demonstration Program are discussed. The program consists of a comparative test and a 90-day manned system test to evaluate an Environmental Control and Life Support System (ECLSS). In the comparative test phase, 14 types of subsystems which perform oxygen and water reclamation functions are to be examined in terms of performance maintenance/service requirements, reliability, and safety. The manned chamber testing phase involves a four person crew using a partial ECLSS for 90 days. The schedule for the program and the program hardware requirements are described.

Space Station Freedom Environmental Control and Life Support System design - A status report

Space Station Freedom (S.S. Freedom) has entered into the Preliminary Design Review (PDR) phase of the program. This paper outlines the Environmental Control and Life Support System (ECLSS) design with emphasis on the systems aspects of the ECLSS. Interactions with other distributed systems, such as data management and electrical power are described. The integration of the ECLSS into the S.S. Freedom pressurized elements and truss are addressed.

Process Material Management in the Space Station Environment

The Space Station will provide a unique facility for conducting material-processing and life-science experiments under microgravity conditions. These conditions place special requirements on the U.S. Laboratory for storing and transporting chemicals and process fluids, reclaiming water from selected experiments, treating and storing experiment wastes, and providing vacuum utilities. To meet these needs and provide a safe laboratory environment, the Process Material Management System (PMMS) is being developed. Preliminary design requirements and concepts related to the PMMS are addressed, and the MSFC PMMS breadboard test facility and a preliminary plan for validating the overall system design are discussed.

Microgravity Sensitivities For Space Station ECLS Subsystems

This report presents a review of the Space Station Environmental Control and Life Support subsystems (ECLSS) for sensitivity to low gravity environments. The object of this review is to categorize sensitivity areas and to quantify the risks. This review addresses all processes from a top level view and then examines in more detail those areas which were considered potential risks. The study has concentrated on the primary function of the subsystems which may be significant to the performance of the particular component and does not address integration of the subsystem and/or the mechanical aspects of the designs. The areas of primary concern were the Atmosphere Revitalization (AR), Water Recovery and Management (WRM), and the Waste Management (WM) subsystems.

Space Station Environmental Control and Life Support System Distribution and Loop Closure Studies

The NASA Space Stations environmental control and life support system (ECLSS) encompasses functional elements concerned with temperature and humidity control, atmosphere control and supply, atmosphere revitalization, fire detection and suppression, water recovery and management, waste management, and EVA support. Attention is presently given to functional and physical module distributions of the ECLSS among these elements, with a view to resource requirements and safety implications. A strategy of physical distribution coupled with functional centralization is for the air revitalization and water reclamation systems. Also discussed is the degree of loop closure desirable in the initial operational capability status Space Stations oxygen and water reclamation loops.

Performance of the Spacelab Astro-1 mission heat pipe radiator

This paper describes the design and performance of the Astro Integrated Radiator System (IRS). The system was recently ground tested and proven successful in rejecting approximately 400 watts of heat. The radiator was constructed from an aluminum panel configured to form two orthogonal planes. Heat pipes were adhesively bonded and riveted to the radiator to isothermalize the surface. The IRS was subjected to a full thermal vacuum test to validate the thermal math model and to qualify the radiator for space flight. The thermal performance met prescribed temperature limits with margins at both extremes, and no mechanical failures occurred.

ECLSS Instrumentation Technology Development for the Space Exploration Initiative

A study of ECLSS instrumentation technologies and an evaluation of SEI ECLSS mission requirements have identified several areas where instrumentation enhancements are required. Attention is given to the ECLSS instrument database fields including development potential, accuracy, cycle time, reliability, resolution, and selectivity. An initial list of instrumentation technologies is recommended for further development to correct each of the deficiencies identified.