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 (although after-launch propulsion of the satellite would be necessary to achieve a stable 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 . 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. In Project HARP, a 1960s joint United States and Canada defence project, a U.S. Navy 100 caliber gun was used to fire a projectile at , reaching an apogee of , hence performing a suborbital spaceflight. However, a space gun has never been successfully used to launch an object into orbit or out of Earth's gravitational pull. Technical issues The large g-force likely to be experienced by a ballistic projectile launched in this manner would mean that a space gun would be incapable of safely launching humans or delicate instruments, rather being restricted to freight, fuel or ruggedized satellites. Getting to orbit A space gun by itself is not capable of placing objects into a stable orbit around the object (planet or otherwise) they are launched from. The orbit is a parabolic orbit, a hyperbolic orbit, or part of an elliptic orbit which ends at the planet's surface at the point of launch or another point. This means that an uncorrected ballistic payload will always strike the planet within its first orbit unless the velocity was so high as to reach or exceed escape velocity. As a result, all payloads intended to reach a closed orbit need at least to perform some sort of course correction to create another orbit that does not intersect the planet's surface. A rocket can be used for additional boost, as planned in