Unlike conventional #space launching methods that relied on rockets, Project HARP (High Altitude Research Project) used very large #guns to fire projectiles into the upper atmosphere. A #HARP gun still holds the record (180 km) for highest altitude achieved by a gun.
@stux the problem is they didnt come close to reaching orbit. The thing is the height you can reach doesnt tell you much of anything about if you got close to orbit. A rocket spends far more energy obtaining its horizontal velocity than it does its height.