Longshot plans 3,000-foot gun for 220-pound Mach 8 launches

Longshot Space Technology plans a 328-foot gun 30 inches in diameter, later extended to about 3,000 feet. The Alameda, California, startup says the full-scale version would be the world's largest gun, firing 220-pound payloads at Mach 8, or eight times the speed of sound.