Yuri Gagarin Coin

On 5 November 1957, Gagarin was commissioned a lieutenant in the Soviet Air Forces having accumulated 166 hours and 47 minutes of flight time. He graduated from flight school the next day and was posted to the Luostari Air Base close to the Norwegian border in Murmansk Oblast for a two-year assignment with the Northern Fleet. On 7 July 1959, he was rated Military Pilot 3rd Class. After expressing interest in space exploration following the launch of Luna 3 on 6 October 1959, his recommendation to the Soviet space programme was endorsed and forward by Lieutenant Colonel Babushkin. By this point, he had accumulated 265 hours of flight time. Gagarin was promoted to the rank of senior lieutenant on 6 November 1959, three weeks after he was interviewed by a medical commission for qualification to the space programme.

The GRAIL mission was managed by NASA's Jet Propulsion Laboratory (JPL) in Pasadena, California, for NASA's Science Mission Directorate in Washington. The mission was part of the Discovery Program managed at NASA's Marshall Space Flight Center in Huntsville, Alabama. Launched as GRAIL A and GRAIL B in September 2011, the probes were renamed Ebb and Flow by schoolchildren in Montana. The probes operated in almost circular orbit near the lunar poles at an altitude of approximately 34 miles, until their mission came to an end in December 2012. The distance between the twin probes altered a bit as they soared over areas of lesser and greater gravity that were caused by visible topological features on the Moon's surface, such as impact craters and mountains--as well as by masses that were secreted beneath the lunar surface. The precise chemical composition of these very alien lakes and seas remained unknown until 2014, when Cassini's radar instrument detected Ligeia Mare, now known to be Titan's second-largest hydrocarbon-filled lake. Ligeia Mare is brimming with an abundance of sloshing methane, and this enormous liquid reservoir is approximately the same size as two of Earth's Great Lakes combined--Lake Michigan and Lake Huron. Many planetary scientists think that the seabed of Ligeia Mare may be blanketed with a thick layer of sludge that is composed of organic-rich compounds.