Development and mechanical properties of construction materials from lunar simulant

Development of versatile engineering materials from locally available materials in space is an important step toward the establishment of outposts on the Moon and Mars. Development of the technologies for manufacture of structural and construction materials on the Moon, utilizing local lunar soil (regolith), without the use of water, is an important element for habitats and explorations in space. It is also vital that the mechanical behavior such as strength and tensile, flexural properties, fracture toughness, ductility, and deformation characteristics are defined toward establishment of the ranges of engineering applications of the materials developed. The objectives include two areas: (1) thermal 'liquefaction' of lunar simulant (at about 1100 C) with different additives (fibers, powders, etc.), and (2) development and use of a new triaxial test device in which lunar simulants are first compacted under cycles of loading, and then tested with different vacuums and initial confining or in situ stress. Details of the development of intermediate ceramic composites (ICC) and testing for their flexural and compression characteristics were described in various reports and papers. The subject of behavior of compacted simulant under vacuum was described in previous progress reports and publications; since the presently available device allows vacuum levels up to only 10(exp -4) torr, it is recommended that a vacuum pump that can allow higher levels of vacuum be utilized for further investigation

Development and mechanical properties of structural materials from lunar simulant

Development of versatile engineering materials from locally available materials in space is an important step toward establishment of outposts such as on the moon and Mars. Here development of the technologies for manufacture of structural and construction materials on the moon, utilizing local lunar soil (regolith), without the use of water, is an important element for habitats and explorations in space. It is also vital that the mechanical behavior such as strength and flexural properties, fracture toughness, ductility, and deformation characteristics are defined toward establishment of the ranges of engineering applications of the materials developed. The objectives include two areas: (1) thermal liquefaction of lunar simulant (at about 1100 C) with different additives (fibers, powders, etc.); and (2) development and use of a traxial test device in which lunar simulants are first compacted under cycles of loading, and then tested with different vacuums and initial confining or insitu stress. The second area was described in previous progress reports and publications; since the presently available device allows vacuum levels up to only 10(exp -4) torr, it is recommended that a vacuum pump that can allow higher levels of vacuum is acquired

Autonomous navigation for artificial satellites

An autonomous navigation system is considered that provides a satellite with sufficient numbers and types of sensors, as well as computational hardware and software, to enable it to track itself. Considered are attitude type sensors, meteorological cameras and scanners, one way Doppler, and image correlator

Development and mechanical properties of construction materials from lunar simulants

The development of construction materials such as concrete from lunar soils without the use of water requires a different methodology than that used for conventional terrestrial concrete. Currently, this research involves two aspects: (1) liquefaction of lunar simulants with various additives in a furnace so as to produce a construction material like an intermediate ceramic; and (2) cyclic loading of simulant with different initial vacuums and densities with respect to the theoretical maximum densities (TMD). In both cases, bending, triaxial compression, extension, and hydrostatic tests will be performed to define the stress-strain strength response of the resulting materials. In the case of the intermediate ceramic, bending and available multiaxial test devices will be used, while for the compacted case, tests will be performed directly in the new device. The tests will be performed by simulating in situ confining conditions. A preliminary review of high-purity metal is also conducted

Cosmic Neutrino Bound on the Dark Matter Annihilation Rate in the Late Universe

How large can the dark matter self-annihilation rate in the late universe be? This rate depends on (rho_DM/m_chi)^2 , where rho_DM/m_chi is the number density of dark matter, and the annihilation cross section is averaged over the velocity distribution. Since the clustering of dark matter is known, this amounts to asking how large the annihilation cross section can be. Kaplinghat, Knox, and Turner proposed that a very large annihilation cross section could turn a halo cusp into a core, improving agreement between simulations and observations; Hui showed that unitarity prohibits this for large dark matter masses. We show that if the annihilation products are Standard Model particles, even just neutrinos, the consequent fluxes are ruled out by orders of magnitude, even at small masses. Equivalently, to invoke such large annihilation cross sections, one must now require that essentially no Standard Model particles are produced.Comment: 4 pages, 2 figures; to appear in the proceedings of the TeV Particle Astrophysics II Workshop, Madison, Wisconsin, 28-31 Aug 200

Utilization of landmark data in attitude/orbit determination

A mathematical model is reported for determination of satellite position, velocity, and attitude using landmark coordinates as observables. This model, although developed with respect to earth stabilized missions, Tiros-N and Nimbus-G in particular, is applicable to any earth stabilized satellite in general

Astrophysical point source search with the ANTARES neutrino telescope

The ANTARES neutrino telescope is installed at a depth of 2.5 km of the Mediterranean Sea and consists of a three-dimensional array of 885 photomultipliers arranged on twelve detector lines. The prime objective is to detect high-energy neutrinos from extraterrestrial origin. Relativistic muons emerging from charged-current muon neutrino interactions in the detector surroundings produce a cone of Cerenkov light which allows the reconstruction of the original neutrino direction. The collaboration has implemented different methods to search for neutrino point sources in the data collected since 2007. Results obtained with these methods as well as the sensitivity of the telescope are presented.Comment: 1 page, 1 figur