It's just a Hanger that are in space ships, but instead you are to high or intoxicated to remember it as a Hanger so you call it a Space Garage.
Person 1: " hey you know the.. um jump at the end of halo 3 where you jump into the um, space garage..."
Person 2: "You mean the Hanger."
Person 1: "Yeah sure that one."
Person 2: "You mean the Hanger."
Person 1: "Yeah sure that one."
by Aussienick December 1, 2016