Kepler's laws of planetary motion law" is what became the Second Law in the set of three; but Kepler did himself not privilege it in that way. Johannes Kepler published his first two laws about planetary motion in 1609, having found them by analyzing the astronomical observations of Tycho Brahe. Kepler's third law was published in 1619. Kepler had believed in the Copernican model of the solar system, which called for circular orbits, but he could not reconcile Brahe's highly precise observations with a circular fit to Mars' orbit—Mars coincidentally having the highest eccentricity of all planets except Mercury. His first law reflected this discovery.
Kosmos 1546 Kosmos 1546 Kosmos 1546 ( meaning "Cosmos 1546") is a Soviet US-KS missile early warning satellite which was launched in 1984 as part of the Oko programme. The satellite is designed to identify missile launches using optical telescopes and infrared sensors. Kosmos 1546 was launched from Site 200/40 at Baikonur Cosmodrome in the Kazakh SSR. A Proton-K carrier rocket with a DM upper stage was used to perform the launch, which took place at 05:53 UTC on 29 March 1984. The launch successfully placed the satellite into geostationary orbit. It subsequently received its Kosmos designation, and the international designator 1984-031A.