2,559 research outputs found

    CELSS and regenerative life support for manned missions to MARS

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    In the mid 1990's, the space station will become a point from which inter-planetary vehicles can be launched. The practicalities of a manned Mars mission are now being studied, along with some newer concepts for human life support. Specifically, the use of organisms such as plants and algae as the basis for life support systems is now being actively considered. A Controlled Ecological Life Support System (CELSS) is composed of several facilities: (1) to grow photosynthetic plants or algae which will produce food, oxygen and potable water, and remove carbon dioxide exhaled by a crew; (2) to process biomass into food; (3) to oxidize organic wastes into CO2; and (4) to maintain system operation and stability. Such a system, when compared to using materials stored at launch, may have distinct weight and cost advantages, depending upon crew size and mission duration, as well as psychological benefits for the crew. The use of the system during transit, as well as in establishing a re-visitable surface camp, will increase the attractiveness of the CELSS concept for life support on interplanetary missions

    Ultraviolet absorption: Experiment MA-059

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    A technique devised to permit the measurement of atmospheric species concentrations is described. This technique involves the application of atomic absorption spectroscopy and the quantitative observation of resonance fluorescence in which atomic or molecular species scatter resonance radiation from a light source into a detector. A beam of atomic oxygen and atomic nitrogen resonance radiation, strong unabsorbable oxygen and nitrogen radiation, and visual radiation was sent from Apollo to Soyuz. The density of atomic oxygen and atomic nitrogen between the two spacecraft was measured by observing the amount of resonance radiation absorbed when the line joining Apollo and Soyuz was perpendicular to their velocity with respect to the ambient atmosphere. Results of postflight analysis of the resonance fluorescence data are discussed

    Intercomparison of ground-based ozone and NO2 measurements during the MANTRA 2004 campaign

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    The MANTRA (Middle Atmosphere Nitrogen TRend Assessment) 2004 campaign took place in Vanscoy, Saskatchewan, Canada (52° N, 107° W) from 3 August to 15 September, 2004. In support of the main balloon launch, a suite of five zenith-sky and direct-Sun-viewing UV-visible ground-based spectrometers was deployed, primarily measuring ozone and NO2 total columns. Three Fourier transform spectrometers (FTSs) that were part of the balloon payload also performed ground-based measurements of several species, including ozone. Ground-based measurements of ozone and NO2 differential slant column densities from the zenith-viewing UV-visible instruments are presented herein. They are found to partially agree within NDACC (Network for the Detection of Atmospheric Composition Change) standards for instruments certified for process studies and satellite validation. Vertical column densities of ozone from the zenith-sky UV-visible instruments, the FTSs, a Brewer spectrophotometer, and ozonesondes are compared, and found to agree within the combined error estimates of the instruments (15%). NO2 vertical column densities from two of the UV-visible instruments are compared, and are also found to agree within combined error (15%)

    Zirconium metal-water oxidation kinetics. I. Thermometry

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    A description is given of the thermometry techniques used in the Zirconium Metal--Water Oxidation Kinetics Program. Temperature measurements in the range 900 to 1500sup0sup 0C are made in three experimental systems: two oxidation apparatuses and the annealing furnace used in a corollary study of the diffusion of oxygen in betabeta-Zircaloy. Carefully calibrated Pt vs Pt--10 percent Rh thermocouples are employed in all three apparatuses, while a Pt--6 percent Rh vs Pt-- 30 percent Rh thermocouple and an optical pyrometer are used in addition in the annealing furnace. Features of the experimental systems pertaining to thermocouple installation, temperature control, emf measurements, etc. are described, and potential temperature-measurement error sources are discussed in detail. The accuracy of the temperature measurements is analyzed

    The NStED Exoplanet Transit Survey Service

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    The NASA Star and Exoplanet Database (NStED) is a general purpose stellar archive with the aim of providing support for NASA's planet finding and characterization goals, stellar astrophysics, and the planning of NASA and other space missions. There are two principal components of NStED: a database of (currently) 140,000 nearby stars and exoplanet-hosting stars, and an archive dedicated to high-precision photometric surveys for transiting exoplanets. We present a summary of the latter component: the NStED Exoplanet Transit Survey Service (NStED-ETSS), along with its content, functionality, tools, and user interface. NStED-ETSS currently serves data from the TrES Survey of the Kepler Field as well as dedicated photometric surveys of four stellar clusters. NStED-ETSS aims to serve both the surveys and the broader astronomical community by archiving these data and making them available in a homogeneous format. Examples of usability of ETSS include investigation of any time-variable phenomena in data sets not studied by the original survey team, application of different techniques or algorithms for planet transit detections, combination of data from different surveys for given objects, statistical studies, etc. NStED-ETSS can be accessed at \tt{http://nsted.ipac.caltech.edu}Comment: To appear in the Proceedings of the 253rd IAU Symposium: "Transiting Planets", May 2008, Cambridge, MA. 4 pages, 2 figure
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