Iridium 77 crosslinks and ground commanding. Iridium 77 Iridium 77 is a communications Satellite which is part of a satellite constellation known as Iridium, named after the 77th chemical element of the periodic table, "iridium". It was launched in 1998 and as of 2014, operational. It is owned and funded by Iridium, a communications company. Iridium 77 is a part of a space-based communications system called Iridium. Conceived, designed, and built by Motorola, the Iridium system provides wireless, mobile communications through a network of 66 satellites in polar, low-Earth orbits. Inaugurated in November 1998, under the auspices of Iridium LLC, this complex
Block (periodic table) the first two quantum numbers) is repeated as many times as required for each pair of electrons it may contain. The result is a compressed periodic table, with each entry representing two successive elements: .The elements which give the greatest number of oxidation states occur in or near the middle of the series from +2 to +7 There is an approximate correspondence between this nomenclature of blocks, based on electronic configuration, and groupings of elements based on chemical properties. The s-block and p-block together are usually considered as the main-group elements, the d-block corresponds to the transition metals, and the