Students will construct CD hovercraft and apply Newton's laws of motion to make them work. They will also investigate how hovercraft reduce friction; learn how the technology is used in training astronauts for space missions; and design their own hovercraft competitions. Materials Old, unwanted compact disk (CD) (1 per hovercraft) Flip-top or pop-up spout from a water bottle (1 per hovercraft) Scissors Sandpaper Round balloon - at least 5-inch size (1 per hovercraft) 1 or 2 low-temperature hot