The engraving reads: "Калуга. Государственный музей истории космонавтики им. К.Э. Циолковского" - "Kaluga. The Konstantin E. Tsiolkovsky State Museum of the History of Cosmonautics". Kaluga is a town. It's definitely not a real coin. It's a souvenir from the museum. It still can have some value among collectors. I had to mirror the picture to read the engraving. If it is actually flipped over the coin can be a rarity.