Project Babylon was a space gun project commissioned by then Iraqi president Saddam Hussein. It involved building a series of "superguns". The design was based on research from the 1960s Project HARP led by the Canadian artillery expert Gerald Bull. There were most likely four different devices in the program.
Two sections of Big Babylon that have been bolted together at Royal Armouries, Fort Nelson, Portsmouth.
A section of the Iraqi "supergun" from Imperial War Museum Duxford
A space gun, sometimes called a Verne gun because of its appearance in From the Earth to the Moon by Jules Verne, is a method of launching an object into space using a large gun- or cannon-like structure. Space guns could thus potentially provide a method of non-rocket spacelaunch. It has been conjectured that space guns could place satellites into Earth's orbit, and could also launch spacecraft beyond Earth's gravitational pull and into other parts of the Solar System by exceeding Earth's escape velocity of about 11.20 km/s. However, these speeds are too far into the hypersonic range for most practical propulsion systems and also would cause most objects to burn up due to aerodynamic heating or be torn apart by aerodynamic drag.
Therefore, a more likely future use of space guns would be to launch objects into Low Earth orbit, at which point attached rockets could be fired or the objects could be "collected" by maneuverable orbiting satellites.
The Quicklauncher spacegun
Two sections of the Project Babylon gun
Project HARP, a prototype of a space gun.
The firing of a space gun in Jules Verne's From the Earth to the Moon