Transfer to the lunar surface, where there are many important satellites for the planet. They are watching the distant cosmos looking for new objects. To protect them, placed a gun, which should reflect all attacks from the air. A huge number of meteorites approaching the space base, take under your gun control and begin to repel massive air strikes. Be careful, the speed of each meteorite is constantly changing and you may not have time to destroy it if you delay. Also consider, the gun can overheat, so do not make frequent volleys, otherwise the station will remain unprotected for a few seconds.