Search Results

This paper highlights the role of electrochemical processes in spacecraft environmental systems development and, by example, describes the fundamentals of these processes.

Space Station Freedom (SSF) modules may be unattended for months during the Man-Tended Capability (MTC) phase of the program. The accumulation of airborne contamination from materials offgassing or contingency incidents (e.g., thermodegradation) raise concerns about crew health and safety from the first crew entry throughout the MTC phase. Computer modelling of the MTC phase, and experiences from previous space flight missions confirm that caution must be exercised during nominal first entry operations. This paper will describe first entry procedures used in the industrial setting and examples of the consequences when first-entry procedures were not followed. Experiences during the Skylab program will be presented to highlight the necessity for carefully planned operations. Anecdotal experiences from previous Spacelab missions and the results of first entry samples from the International Microgravity Laboratory (IML-1) will be detailed.

Humans are able to acclimatize and later adapt to extreme altitudes, and this will be shown to be beneficial to the human with respect to microgravity and spacecraft environment. Treating the astronaut as a subsystem, which can be enhanced and modified to ultimately benefit the whole spacecraft is an approach that is necessary to forge the next generation of human spaceflight. ...Treating the astronaut as a subsystem, which can be enhanced and modified to ultimately benefit the whole spacecraft is an approach that is necessary to forge the next generation of human spaceflight. A spacecraft environment that is maintained at a pressure of 16 kPa (primarily oxygen) would be both well within the realm of possibility of an astronaut’s physiology and would provide significant benefits for the all the subsystems of a spacecraft from the large intra-stellar spaceship to the EVA suit. ...Treating the astronaut as a subsystem, which can be enhanced and modified to ultimately benefit the whole spacecraft is an approach that is necessary to forge the next generation of human spaceflight. A spacecraft environment that is maintained at a pressure of 16 kPa (primarily oxygen) would be both well within the realm of possibility of an astronaut’s physiology and would provide significant benefits for the all the subsystems of a spacecraft from the large intra-stellar spaceship to the EVA suit.

The ROSETTA mission is a European Space Agency spacecraft which will rendezvous with the comet Wirtanen. The spacecraft will deploy a Surface Science Package (SSP) to land on the comet. ...Thus, the heater power demand at 5.25 AU has to be low, when the spacecraft is in Deep Space Hibernation mode. Prior to the comet rendezvous, the spacecraft is woken up. ...With a fully operational payload, the ROSETTA spacecraft establishes an orbit around comet Wirtanen. The spacecraft follows the comet during its approach to the sun.

Research in microgravity (low-gravity) combustion promises innovations and improvements in fire prevention and response for human-crew spacecraft. Findings indicate that material flammability and fire spread in microgravity are significantly affected by atmospheric flow rate, oxygen concentration, and diluent composition. ...Research on smoke-particle changes in microgravity promises future improvements and increased sensitivity of smoke detectors in spacecraft. Research on fire suppression by extinguishing agents and venting can yield new information on effective control of the rare, but serious fire events in spacecraft. ...Research on fire suppression by extinguishing agents and venting can yield new information on effective control of the rare, but serious fire events in spacecraft.

This paper emphasizes the requirements peculiar to spacecraft fluid mechanical systems. Although the design requirements for the fluid power systems used in aircraft, tactical missiles, and launch vehicles have been established successfully, criteria for the design of gaseous and liquid systems in spacecraft demand additional considerations. ...Although the design requirements for the fluid power systems used in aircraft, tactical missiles, and launch vehicles have been established successfully, criteria for the design of gaseous and liquid systems in spacecraft demand additional considerations. Elements of fluid and mechanical systems in manned and unmanned spacecraft are discussed, and additional visibility is provided for those design requirements that differ from earth-oriented vehicles. ...Elements of fluid and mechanical systems in manned and unmanned spacecraft are discussed, and additional visibility is provided for those design requirements that differ from earth-oriented vehicles.

(ADA) is developing a handheld fine water mist fire extinguisher for use on manned spacecraft and in future planetary habitats. This design employs only water and nitrogen as suppression agents to allow local refill and reuse. ...Continued development will result in prototype hardware suitable for use on future manned spacecraft.

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.

One of the long-standing concerns in space exploration is the presence of trace organic contaminants in recycled spacecraft water supplies. At present, water samples on the International Space Station (ISS) are collected at regular intervals, stored in Teflon™-lined containers, and returned to Earth for characterization. ...With SPE, the organic contaminants in the spacecraft water can be trapped and concentrated on a thin membrane or other extraction medium, with the resulting effluent recycled back into the water supply as opposed to being stored and returned to Earth. ...Results from an evaluation of this concept using synthetic spacecraft water and a range of extraction materials are described, along with the findings from a KC-135 flight evaluation of the effectiveness of and experimental challenges in implementing this concept in microgravity.

Most interestingly, the relative state errors are significantly less than the individual errors in the two spacecraft absolute states and that the technique is virtually immune to refraction and relativistic effects.

The focus is on the unique issues associated with the CEV and future spacecraft including operation in reduced gravity and enriched oxygen ambients. Inert gas agents such as carbon dioxide, nitrogen and helium have different minimum extinguishing concentrations (MEC) in microgravity compared to normal gravity; in most instances the MEC in microgravity being higher than in normal gravity.

Exhaustive testing and analysis of Vapor Compression Distillation technology has proven its overall readiness as a wastewater processor for the recovery of water in orbiting and interplanetary spacecraft. In conjunction with Boeing Aerospace and Electronics and the National Aeronautics and Space Administration, Life Systems' technical team has been focusing on verifying and improving performance characteristics, micro-gravity compatibility, reliability and maintainability aspects of the Vapor Compression Distillation design.

This paper describes a Stirling Cycle Refrigerator that has been built and tested by Stirling Technology Company (STC) for the NASA Marshall Space Flight Center (MSFC). Its intended application is the space station food refrigerator freezer. The Stirling Cycle Refrigerator described herein has few moving parts, is nontoxic to both humans and the environment, is insensitive to gravity, and has a moderate efficiency. Its temperature setpoint is adjustable, making it adaptable to other space station applications including a -70 °C freezer and freeze drier, a -183 °C freezer, and a -196 °C snap freezer. Test results have been very promising, with a Coefficient of Performance (COP) of 1.1 at -26 °C (-15 °F) and a heat load of 130 watts. Reliability tests on individual components and the entire Stirling Cycle Refrigerator system show a 10-year life is possible. In addition, the benefits of using this technology for the space station refrigerator freezer will be described.

An update of a Two-Phase Thermal Management System concept is presented including hardware status for flight prototypic components, modeling techniques, and terrestrial test results for both preprototype and some prototypic hardware. A test plan for a microgravity test on a KC 135 is discussed.

A significant advantage of utilizing forced convection boiling heat transfer for spacecraft thermal management applications is that high heat fluxes are yielded that allow heat exchange equipment to be substantially compacted and reduced in mass. ...To date, two-phase heat transfer has not been utilized aboard spacecraft due to the uncertainty of the influence of gravity on the fluid dynamics and heat transfer within the heat exchange equipment.

Five different materials representative of those found in spacecraft were pyrolyzed at temperatures below the ignition point with conditions controlled to provide repeatable sample surface temperatures and air flow conditions. ...Even though the analysis of these data is ongoing, information from the various instruments and the calculated mean particle sizes has important implications for the design of spacecraft smoke detectors. These implications are reviewed in this paper relative to the operating principles of existing smoke detection technology, These results can be used to establish design requirements for smoke detectors for future spacecraft. ...These implications are reviewed in this paper relative to the operating principles of existing smoke detection technology, These results can be used to establish design requirements for smoke detectors for future spacecraft.

A rotating spacecraft which encloses an atmospheric pressure vessel poses unique challenges for thermal control. ...The baseline system incorporates fans, thermoelectric coolers, heat fins and conducting plates to continuously and reliably remove thermal energy from the spacecraft's atmospheric pressure vessel. We present an assessment of a condensing heat exchanger with novel design enhancements to promote efficient operation in a partial gravity environment. ...Our approaches are validated by experimental data from a prototype of the thermal control subassembly within a new engineering mockup of the spacecraft's payload module. This work provides novel insights into issues of thermal control in artificial gravity environments.

This instrument is designed to monitor the quality of recycled potable water aboard spacecraft such as the International Space Station. Phase I involved selecting and validating methods for low mass-to-charge ratio (m/z) cations and anions by using a slightly modified commercial CE instrument as a model.

Testing was conducted aboard the NASA-JSC KC-135 reduced gravity aircraft using a prototype two-phase thermal management system for large spacecraft. A clear section of two-phase line enabled visual and photographic observation of the flow regimes.

The basic requirement of a transfer system of storable propellants is to provide propellant in sufficient quantity to assure proper engine operation. Various vehicle motions, such as rotational maneuvers, may result in dislocation of propellant from the tank outlet region, thus changing flow rates and mixture ratios and causing impaired performance. In this paper a promising method of propellant relocation, settling by means of an induced gravitational field, is considered.