On This Day in Space Exploration

    February 15   15 February 1564 Galileo Galilei, portrait by Domenico Tintoretto or Francesco Apollodoro, c. 1602–1607. Credit: National Maritime Museum/Wikimedia Commons Galileo Galilei, Italian natural philosopher, astronomer, and mathematician who played a major role in the Scientific Revolution was born in Pisa, Italy, on February 15, 1564. In 1589 he became professor of mathematics at the University of Pisa, and then from 1592 to 1610 at the University of Padua. In 1610 he was appointed philosopher and chief mathematician to the Grand Duke of Tuscany.    Galileo was one of the first scientists to use a telescope for astronomical observations in 1609–1611. His discoveries include mountains on the Moon, stars of the Milky Way, the phases of Venus, the four largest moons of Jupiter (now called the Galilean satellites), and the analysis of the motion of sunspots. Although most of these discoveries were made independently by others, no one understood th...

  February 14    14 February 1972 Artist's depiction of a Ye-8-5 spacecraft Luna 20, the second successful Soviet lunar sample-return mission, was launched from the Baikonur Cosmodrome on February 14, 1972, at 03:27:58 UTC . The primary objective of the mission was to land on the Moon, collect lunar soil, and return it to Earth. The spacecraft  entered lunar orbit on February 18,  landed on the Moon on February 21, and its capsule returned to Earth on February 25,  carrying 55 grams of collected lunar samples.    Luna 20 was based on the Ye-8-5 spacecraft body, consisting of two attached stages, an ascent stage mounted on top of a descent stage. The lander stood 3.96 meters tall and had an unfueled landed mass of 1880 kg. With a full load of fuel Luna 20 launch mass was 5,725 kg.    The descent stage was the same as the Ye-8 lower stage for the Lunokhod rovers, a cylindrical body with four protruding landing legs, fuel tanks, a land...