Search Results

This part of the manual presents methods for arriving at a solution to the problem of spacecraft inflight equipment environmental control. The temperature aspect of this problem may be defined as the maintenance of a proper balance and integration of the following thermal loads: equipment-generated, personnel-generated, and transmission through external boundary.

A life support system (LSS) is usually defined as a system that provides elements necessary for maintaining human life and health in the state required for performing a prescribed mission. The LSS, depending upon specific design requirements, will provide pressure, temperature, and composition of local atmosphere, food, and water. It may or may not collect, dispose, or reprocess wastes such as carbon dioxide, water vapor, urine, and feces. It can be seen from the preceding definition that LSS requirements may differ widely, depending on the mission specified, such as operation in Earth orbit or lunar mission. In all cases the time of operation is an important design factor. An LSS is sometimes briefly defined as a system providing atmospheric control and water, waste, and thermal management.

It is therefore imperative to develop a safe, effective method of microbial control. Spacecraft application dictates a more stringent set of requirements for biocide selection than is usually necessary for terrestrial situations. ...Toxicity of the biocide is the driving factor for disinfectant choice in spacecraft. This concern greatly reduces the number and types of chemical agents that can be used as disinfectants. ...Furthermore, the chemical and toxicological properties of these biocides and others are considered in relation to disinfection of spacecraft and allied hardware.

CJB Developments Limited, (CJBD) assisted by a number of distinguished consultants, undertook a study on behalf of the European Space Agency (ESA) to identify Critical Technologies relating to Spacecraft Habitability. Critical Technologies in this context are those defined as requiring a solution in order that the objectives of the European Manned Space Infrastructure (EMSI) can be met.

When construction of Space Station Freedom reaches the Permanent Manned Capability stage, plans call for the Water Recovery and Management Subsystem to treat distilled urine, spent hygiene water, and humidity condensate in order to reclaim water of potable quality. The reclamation technologies currently baselined to process these wastewaters include adsorption, ion exchange, catalytic oxidation, and disinfection. To ensure that baselined technologies will be able to effectively remove those compounds that present health risks to the crew, the National Research Council has recommended that additional information be gathered on specific contaminants in wastewaters representative of those to be encountered on Space Station. This paper reports the efforts by the Water and Food Analytical Laboratory at the Johnson Space Center to enlarge the database of potential contaminants in humidity condensate.

The Ranger Telerobotic Flight Experiment is a highly complex teleoperated spacecraft, requiring direct human control of 36 major degrees of freedom. The University of Maryland Space Systems Laboratory and the NASA Ames Research Center are cooperating on the development of a virtual reality control station to streamline human interfaces with the Ranger spacecraft. ...The University of Maryland Space Systems Laboratory and the NASA Ames Research Center are cooperating on the development of a virtual reality control station to streamline human interfaces with the Ranger spacecraft. This describes the design and integration of the Ranger Command Chair, a system incorporating fully immersive helmet-mounted stereo displays with head tracking, hand tracking for direct positional control, and supplemental controls and displays to allow a single operator to functionally control the entire vehicle.

Current studies suggest that Airborne Endospore Bioburden (AEB) may be used as an indicator of spacecraft cleanliness. AEB, as measured in closed environment air sampling under laboratory conditions and in the Environmental Control and Life Support System at Marshall Space Flight Center, has indicated that increased total counts of airborne endospores can be correlated to surface microbial contamination. ...AEB measurements have the potential to be used in monitoring surface bioburden to anticipate buildup on critical spacecraft hardware and expedite remediation.

Water is a critical commodity for spacecraft crews, requiring extreme conservation and reclamation strategies. In addition to suppression of the immune system in spaceflight, enhancement of bacterial growth and antimicrobial resistance in weightlessness raise serious concerns regarding microbial contamination of water systems. ...We report on the combination of methods into highly sensitive, rapid technologies for detecting specific target bacteria and assessing their viability in spacecraft water.

Also described are the primary mission objective, the spacecraft configuration, requirements and design drivers, mission environments, and design parameters.

A submerged membrane biological reactor (MBR) was evaluated for treatment of a spacecraft wastewater analog. The aerobic MBR (a modified CSTR) had a 12 L working volume, submerged 0.2 μm membrane filter, 12.6 h hydraulic retention time (simulated 2 person crew), and infinite solids retention time.

Currently, Space Shuttle flights rely upon stored expendables for the generation of potable water (via fuel cells) and waste fluids such as himidity condensate and urine are stored for return to earth and subsequent disposal. Water is not presently recycled due to the relatively short nature of each mission. On future long duration Space Station flights (i.e., 90-day resupply) most of the water from urine, humidity condensate, hygeine water (shower and hand wash) and ultimately clothes and dishwashers will be recycled to eliminate the launch weight penalties associated with large amounts of water. Consider that each crewperson requires about 17 liters (4.5 gallons) of water daily. On a 90-day mission with a six member crew, a water supply of 9159 kilograms (20,242 pounds) would be required.

Manned activity within a closed environment will generate a variety of wastes, both stable and potentially biodegradable. The wastes can never be totally eliminated: waste management aims to make a change of form which is both advantageous in terms of volume and hazard reduction and which does not compromise crew health and safety. Micro-organisms will be carried on board by the crew and will be present in the wastes. The fundamental philosophy of our waste management concept is to specifically exclude or specifically include this inherent microbial activity. The complete safe stabilization of waste requires its exclusion while the ultimate need of element recycle will rely on microbial conversion processes.

A two-stage steam gasification and reforming process was evaluated for converting wastes generated within enclosed habitable environments into synthesis gas (CO & H2) and other recyclable inorganic species, i.e. water, CO2 and inorganic salts. Waste compounds used in the experimentation included: cellulose; urea; methionine; sucrose; butyric acid; Igepon TC-42 - a particularly (chemically) stable soap selected by NASA for use in space life support systems; wheat straw and a high density polyethylene. The compounds were tested individually and in combination to simulate the wastes anticipated within enclosed habitat environments.

The operational suitability of using laptop computers in crew work stations for future spacecraft and lunar/planetary bases has been assessed by evaluating conceptual mockups of these work stations. ...Further, the use of laptop computers in place of traditional fixed consoles was found to be suitable for most crew work stations and work sites in future spacecraft and space bases. With these analysis and evaluation results in hand, NASA will be able to take full advantage of capabilities currently available in laptop computers in future crew work station design.

The capability of a multifunction display system to present data regarding malfunctioning manned spacecraft systems is illustrated. The development of formats for abnormal operations is based on the correspondence between cognitive requirements of the crewmember and displayed information. ...Three different stages of cognitive processing are identified and associated spacecraft formats are developed. System architecture provides for the display of required information tailored to crewmember requirements in identifying, understanding, and solving malfunctions via a simple multifunction display interface.

Controlling microbial growth and biofilm formation in spacecraft water-distribution systems is necessary to protect the health of the crew. Methods to decontaminate the water system in flight may be needed to support long-term missions. ...The biofilms were developed by placing the coupons in a manifold attached to the effluent line of a simulated spacecraft water-distribution system. After biofilms were established, the coupons were removed and placed in a treatment manifold in a separate water treatment system where they were exposed to the chemical treatments for various periods.

In space engineering, a thorough thermal analysis on a spacecraft is necessary to evaluate structural stresses, and above all thermoelastic displacements (e.g. instrument pointing).

., carbon dioxide and water, as an adjunct to the Life Support Systems (LSS) required in manned spacecraft, e.g., Space Station Freedom, and planetary bases, e.g., on the Moon and Mars. These products will be synthesized using inorganic processes based on chemical engineering principles, making use of the major components of metabolic waste, carbon, hydrogen, and oxygen. ...Direct Conversion Indirect Conversion Useful Products on Spacecraft The benefits to be derived from the program are: (1) conversion of metabolic wastes to useful products for use on manned spacecraft and planetary bases, (2) the use of indigenous Martian resources for the production of useful products for life support, base construction, and propulsion system fueling/refueling, (3) weight savings which result from reduced on-board supply requirements; (4) production of useful products based on efficient engineering principles, i.e., mass, volume and energy, and (5) reduced resupply from Earth which enable economic exploration and colonization of space. ...Direct Conversion Indirect Conversion Useful Products on Spacecraft The benefits to be derived from the program are: (1) conversion of metabolic wastes to useful products for use on manned spacecraft and planetary bases, (2) the use of indigenous Martian resources for the production of useful products for life support, base construction, and propulsion system fueling/refueling, (3) weight savings which result from reduced on-board supply requirements; (4) production of useful products based on efficient engineering principles, i.e., mass, volume and energy, and (5) reduced resupply from Earth which enable economic exploration and colonization of space.

There currently exist three practical processes for reduction of carbon dioxide in manned spacecraft environmental control and life support systems. The Sabatier (SCRS) and the Bosch (BCRS) Carbon Dioxide Reduction Subsystems are well known, while the Advanced Carbon Dioxide Reduction Subsystem (ACRS) is more recently developed.

Important parameters in designing regenerable adsorption beds for spacecraft life support systems are defined. Typical applications include synthetic zeolite, which is used for carbon dioxide removal; and silica gel, which dehumidifies the atmospheric gas prior to passing it through the zeolite beds.