Search Results

A three country effort (U.S., Russia, and Bulgaria) has upgraded the plant growth facilities on the Mir Space Station and used the new facility to grow wheat for 90 days. The Svet plant-growth facility was reactivated and used in an initial experiment as part of the Shuttle/Mir program, August to November, 1995. The Svet system, used first to grow cabbage and radish during a 1990 experiment, was augmented by the addition of a U.S. developed Gas Exchange Measurement System (GEMS) that measures a range of environmental parameters plus transpiration, photosynthesis, and possibly respiration. Environmental parameters include cabin, chamber, root-zones, and leaf temperatures. Light levels, relative humidity, oxygen, and atmospheric pressure are also measured. High-accuracy water-vapor and carbon-dioxide concentrations and differences are measured using specially developed IRGA systems.

Of the possible Life Support Systems evaluation criteria, the criterion of "integral reliability" is proposed. This criterion incorporates three main indices: reliability, mass, and quality of life. It is possible to interrelate these indices only if the space mission is considered as a whole. It is shown that there must exist a LSS mass optimum with respect to mission reliability. The specific form of "integral reliability" expression and the number of terms depend on the mission scenario. This work considers different LSS for orbital station, Lunar base, and Mars mission scenarios.

This paper presents the results of the breadboarding study phase of a Fourier transform infrared spectrometer (FTIR) based trace gas monitor for the use on-board a manned spacecraft. The FTIR system configuration includes a multiple-reflection long path gas cell, a half-wavenumber resolution interferometer, and a mercury-cadmium-telluride (MCT) detector. In the study, the emphasis was put on the achievement of a predefined analytical performance using a state-of-the-art multivariate analysis method. Robustness of the employed algorithms was to the fore rather than a sophisticated FTIR instrumentation. The achieved results show high accuracy in detecting trace gases in the range between the (lower) long-term and (higher) short-term Spacecraft Maximum Allowable Concentration (SMAC) limits. The project has demonstrated a good proof-of-concept for the use of an FTIR system in manned space flights.

ESARAD is an integrated suite of analysis tools for thermal radiative analysis. The suite provides modules for: • Geometry Definition; • Calculation of view factor, radiative exchange factor and solar, albedo and planet flux results; •Visualization of models in orbit with pre- and post-processing of radiative and thermal results; • Reporting of all aspects of the model; and • Generation of Input Files for Thermal Analysis tools. ESARAD is driven by a fully developed GUI, providing the user with a simple, intuitive windows, menus, forms interface to all its features. A modern, block structured language can also be used to run ESARAD. This gives the advanced user great power and flexibility to perform the most complex analyses. ESARAD was designed and developed between 1988 and 1991 to replace the VWHEAT software used by ESA at that time.

In an on-going harmonized ESA/NIVR project, performed by Stork Comprimo and TNO-MEP, the removal of the carbon dioxide with membranes is studied. The use of membrane gas absorption for carbon dioxide removal is currently hampered by the fact that the commonly used alkanolamines result in leakage problems when using polyolefin membranes. This prevents the use of membrane gas absorption for carbon dioxide in spacecrafts. TNO has recently discovered classes of liquids for carbon dioxide absorption which are suitable for use with cheap polyolefin membranes. This opens the possibility for using membrane gas absorption for carbon dioxide control in spacecrafts. In the project the performance of membrane gas absorption for the removal of carbon dioxide from gas streams having a chemical composition representative of spacecraft conditions are determined experimentally.

Environment Control and Life Support Systems (ECLSS) are necessary for missions of human beings into outer space. The longer the missions are the more the closure of the ECLSS loops is demanded. Since 1985 in a harmonised multi-phased programme under ESA (European Space Agency) and DARA comtract (German Space Agency) the Air Revitalisation System ( ARS )and its technologies are being developed. This paper reviews the current status of the complete system and presents the latest development results of the three key elements: The solid amine CO2 concentrator. The Sabatier reactor. The fixed alkaline electrolyser.

During 1995, we tested instruments and attempted a seed-to-seed experiment with Super-Dwarf wheat in the Russian Space Station Mir. Utah instrumentation included four IR gas analyzers (CO2 and H2O vapor, calculate photosynthesis, respiration, and transpiration) and sensors for air and leaf (IR) temperatures, O2, pressure, and substrate moisture (16 probes). Shortly after planting on August 14, three of six fluorescent lamp sets failed; another failed later. Plastic bags, necessary to measure gas exchange, were removed. Hence, gases were measured only in the cabin atmosphere. Other failures led to manual watering, control of lights, and data transmission. The 57 plants were sampled five times plus final harvest at 90 d. Samples and some equipment (including hard drives) were returned to earth on STS-74 (Nov. 20). Plants were disoriented and completely vegetative. Maintaining substrate moisture was challenging, but the moisture probes functioned well.

NASA has supported a research program in plant space biology as well as supporting ground-based gravitational biology investigations for over three decades. The research in plant space biology is advancing at an increasingly rapid rate as more versatile hardware is developed for flight. The new hardware has supported experiments which have and will continue to allow a greater variety of research approaches. The overall goal is focused on characterizing and explaining the effects of gravity on growth, development, composition and functions of higher plants.

Space: so far so expensive! If the Space Station has a 6-year delay in respect to the initial schedule, Lunar Base will have a 15-year delay, if we continue to think in a conservative way. We need a new approach for the missions' and manned systems' design. The ISU-IACSA (Italian Affiliate Campus for Space Architecture of the International Space University) current activities are focused on "self-constructing" and "self-shaping habitat." The major cost of a space mission is essentially the transfer "flights" from Earth to Space, and, in the case of the Moon, all the steps to go there, space station's stops included. Many flights are necessary to build a Lunar base due to the large number of elements by which it is composed; in particular, the current NASA's Lunar Base configuration for 12 people is based on 5 flights minimum and on a lot of time to be spent by the astronauts once on the surface of Moon to assemble the base (in a space suit).

Since the earliest days of manned space ventures, the search for authentic analogs of space exploration have been investigated. The primary purpose for these analogs has been to reduce risk and cost. There are many similarities between operational space habitats and ocean habitats and these can be significantly exploited to provide an efficient terrestrial based model for testing space bound systems and crews. The National Aeronautics and Space Administration embarked on such a seafloor analog to the space station in 1969 called Tektite. Tektite investigated a single mission component, crew psychology. But the range of valid components is considerably wider ranging, including analogous system design, parallel operational functionality and mission compatibility.

The efficacy of analogous test beds for space missions was rated by a diverse group of scientists and engineers with respect to short and long duration Lunar and Mars mission scenarios. Ratings for fidelity, repeatability, adaptability and availability of Historical Data, internal habitat factors and external environment factors were made for analog environments including: Space Station, Space Shuttle, Polar Environments, Underwater Environments (not Submarine), Deserts, Expeditions, Submarines, Closed Systems, Virtual Environments. Individual factors rated must be considered against a fully defined mission scenario to make the best case by case selection for testing, however, the overall highest average ratings were for polar environments, and submarines.

Description of design principles of thermocontrol system for small subsatellites “Magion - 4, 5” is presented. Passive type of system is intended to support the temperature level (-10…50) °C in inner volume of equipment compartment at solar subsatellite orientation and in temporary Earth shadow. Heat energy balance of object at necessary temperature range is provided by utilization of radiating surfaces with defined areas, by thermal connection of hot and cold subsatellite parts and by adaptation of constructive subsatellite elements to solve thermal tasks. Stages of heat pipe design, its development and testing separately and installed into object, thermovacuum test of subsatellite are presented. Initial time range of flight operation of thermocontrol system is analyzed as well.

The original thermal design of the Landsat-7 Enhanced Thematic Mapper Plus (ETM+) scanner was inherited from Landsat-4, 5 and 6 at the instrument Critical Design Review (CDR). The ETM+ Auxiliary Electronics Module (AEM) and Full Aperture Calibrator (FAC) are new components and had no heritage thermal design at the CDR. More than a year after the CDR, the Landsat-7 program was transferred from the U.S. Air Force to the National Aeronautics and Space Administration (NASA). NASA added the sun-pointing safehold mode which has significant thermal impacts on the instrument. The temperature predictions for the scanner were much colder than the survival temperature limits in the sun-pointing safehold cold case. This paper presents thermal solutions to the cold survival problems. The solutions have no major impacts on the program cost and schedule.

The International Space Station Alpha Electrical Power System has a thermal control system to remove heat from the batteries and power distribution electronics. A major subsystem of this thermal loop is the Pump and Flow Control Subassembly (PFCS) which functions as an ammonia fluid distribution and control subsystem. This paper will detail the development, construction and operational performances of the PFCS hydraulic elements operating with an ammonia fluid. These elements include flow meter, accumulator, flow control valve, and pumps. The electronics which are utilized to operate these hydraulic elements will also be described. The combination of these hydraulic and electronic elements form a subassembly to safely control a hazardous, low viscosity fluid.

The early external active thermal control system (EEATCS) is designed to cool the U.S. Laboratory (USL), during early assembly stages of the International Space Station (ISS), to support assured early research (AER). The ISS is assembled on orbit over a period of about 5 years and over 40 stages. During later stages, about half way through the assembly, the USL is cooled by the external active thermal control system (EATCS), but that system is not available during early stages. To assure research, during early stages, the USL is cooled by the EEATCS; at a later stage, the USL cooling is switched to EATCS. During early stages, electric power is provided by the integrated truss segment (ITS) P6, which consists of photovoltaic (PV) arrays to convert sunlight into direct current power, an integrated equipment assembly (IEA) to support hardware required to store and condition electric power, and a long spacer to provide spacing between outboard power modules.

The ability to remove semi-volatile organic compounds such as alcohol from waste water streams has challenged the design of the International Space Station (ISS) water processor. The current ISS water processor utilizes an aqueous phase catalytic oxidation system to convert these organic compounds to their corresponding organic acids, and to some extent carbon dioxide, which are then easily removed via ion exchange resin. This oxidation system also provides a microbiological control function within the water processor. This paper summarizes testing conducted utilizing both simulated and real waste water on a development catalytic oxidizer. In addition, information is presented on the system schematic and reactor configuration planned for the upcoming Volatile Removal Apparatus flight experiment scheduled for STS 84 to be flown in May 1997.

The International Space Station (ISS) redesign made operational and interface requirements changes to the previous Space Station Freedom baseline. These changes include Oxygen Generation Assembly (OGA) production only on the daylight side of each orbit; nitrogen interface pressure reduction to 100 +/- 10 psia (690 +/- 69 kPa); and available production rates of nominal, nominal +10%, and nominal -10%. In 1994 a test program was initiated at MSFC to verify OGA capabilities for cyclic operation. The liquid feed solid polymer electrolyzer from the 1990 OGA Comparative Test was refurbished and modified as required. This paper describes the operation of the test unit, and presents a discussion of the test data and test results.

The Trace Contaminant Control System (TCCS) removes most hazardous contaminants from the space station atmosphere using a carbon bed, but some must be destroyed in a high temperature catalytic oxidizer. While the oxidizer is protected from catalyst poisons by the carbon bed, if contaminant loads are greater than anticipated, the catalyst may be exposed to a variety of poisons. Thus, we studied the effect of halocarbons, sulfides and nitrogen compounds on the catalytic activity and the products produced. We found that even if poisoning occurs, the catalyst will recover, and will not produce toxic partial oxidation products.

Flight experiments are being developed to assess the microgravity performance of U.S.-developed physical/chemical life support technologies baselined for operation on the International Space Station (ISS). The experiments will take advantage of flight opportunities available on the Space Shuttle prior to the production of ISS flight systems. Early microgravity demonstrations of these technologies will allow the ISS life support system to be developed from flight-proven processes, thereby reducing programmatic risks and enhancing overall life support efficiencies. This paper will provide an overview of the life support flight experiment program.

The Early Human Testing Initiative (EHTI) Phase I Human Test, performed by the Crew and Thermal Systems Division at Johnson Space Center, demonstrated the ability of a crop of wheat to provide air revitalization for a human test subject for a 15-day period. The test demonstrated three different methods for control of oxygen and carbon dioxide concentrations for the human/plant system and obtained data on trace contaminants generated by both the human and plants during the test and their effects on each other. The crop was planted in the Variable Pressure Growth Chamber (VPGC) on July 24, 1995 and the test subject entered the adjoining airlock on day 17 of the wheat's growth cycle. The test subject stayed in the chamber for a total of 15 days, 1 hour and 20 minutes. Air was mixed between the plant chamber and airlock to provide oxygen to the test subject and carbon dioxide to the plants by an interchamber ventilation system.