The Russian names scratched on the door of Poole's room in Star City indicate it was previous occupied by cosmonauts Valentina Tereshkova, Alexei Leonov and Anastasia Belikova, the last one being the (fictional) first female cosmonaut to walk on the moon in the first season.
The Soviet engineer at Danielle's room at Star City is a reference to Sergei Korolev, the Soviet Union's leading rocket engineer. Despite his skills, he was sent to prison and even Gulag by Stalin's secret police for political reasons in 1938. He had spent several years imprisoned when he became the most important engineer in the Soviet space program.
At the end, when the Marines start humming on the LSAM, they're humming Richard Wagner's "Ride of the Valkyries" which is the regimental march of the Parachute Regiment of the British Army. This is also what Col. Kilgore plays from his helicopter in "Apocalypse Now"
Kelly Baldwin (Nguyen Thi Nanh) was born on July 14, 1966.