The Russian Academy of Sciences and Federal Space Agency, together with the participation of many international organizations, worked toward the launch of the RadioAstron orbiting space observatory with its onboard 10-m reflector radio telescope from the Baikonur cosmodrome on July 18, 2011. Together with some of the largest ground-based radio telescopes and a set of stations for tracking, collecting, and reducing the data obtained, this space radio telescope forms a multi-antenna groundspace radio interferometer with extremely long baselines, making it possible for the first time to study various objects in the Universe with angular resolutions a million times better than is possible with the human eye. The project is targeted at systematic studies of compact radio-emitting sources and their dynamics. Objects to be studied include supermassive black holes, accretion disks, and relativistic jets in active galactic nuclei, stellar-mass black holes, neutron stars and hypothetical quark stars, regions of formation of stars and planetary systems in our and other galaxies, interplanetary and interstellar plasma, and the gravitational field of the Earth. The results of ground-based and inflight tests of the space radio telescope carried out in both autonomous and ground-space interferometric regimes are reported. The derived characteristics are in agreement with the main requirements of the project. The astrophysical science program has begun.
Millimetron is a Russian-led 12 m diameter submillimeter and far-infrared space observatory which is included in the Space Plan of the Russian Federation for launch around 2017. With its large collecting area and state-of-the-art receivers, it will enable unique science and allow at least one order of magnitude improvement with respect to the Herschel Space Observatory. Millimetron will be operated in two basic observing modes: as a single-dish observatory, and as an element of a groundExp Astron (2009) space very long baseline interferometry (VLBI) system. As single-dish, angular resolutions on the order of 3 to 12 arc sec will be achieved and spectral resolutions of up to a million employing heterodyne techniques. As VLBI antenna, the chosen elliptical orbit will provide extremely large VLBI baselines (beyond 300,000 km) resulting in micro-arc second angular resolution.
Abstract. In this article we address a problem of determination of light pressure upon space structures of the complex geometric shape. For the surface element, we wrote a condition that this element can interact with light only from the front side, not from the back side. This condition To in the form of series of Chebyshev polynomials of the first kind. Chebyshev expansion lets us move to the series of tensors of increasing rank for the problem of determination of force and moment. We obtained expressions for the fiber method for determination of light pressure on space structures of complex geometry taking into account self-shadowing and reflections within the structure. We also give the expressions for tensor parametrization by the specularity coefficient in case of specular-diffuse reflection. For these expressions we calculated the principal moment and force upon two-sided flat solar sail, spherical and cylindrical bodies, and approximated light pressure upon a perspective space observatory Millimetron. The proposed expressions can be used in the ballistic analysis of solar sails and other space objects, which are significantly affected by the radiation pressure. Also, these results can be used to analyze the dynamics of movement of large-scale space structures around the center of gravity under the light pressure.
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