Not to be confused with the conspiracy factory that is Project HAARP (High Frequency Active Aural Research Program), Project HARP (High Altitude Research Project) was a joint initiative between the United States and Canada to research the use of ballistics to deliver objects into the upper atmosphere and beyond.
In lay terms, the project was established to create a cartoonishly large gun to shoot things into space. The sole fruit of this partnership, a massive toppled gun barrel, still remains on the Barbados test site.
Designed by mad ballistic engineer Gerald Bull, the gun itself was originally built from a 50-caliber naval cannon, like what might be seen on a battleship, and was later doubled to 100 caliber, making the gun too big for effective military application, but seemingly perfect for satellite delivery. Not designed for delivering human subjects, the cannon fired smaller projectiles in a sabot that would protect the payload during the firing and would fall away as the satellite rose. At its apex, the gun was able to fire an object a staggering 112 miles into the sky, setting the 1963 world record for gun-launched altitude at 93 KM.
As the project continued, installing similar guns in further locations, the Barbados gun was abandoned in the late 1960s and left to rust on its original launch site. Looking more like a painted sewer pipe than a Godzilla-size gun barrel, the original Project HARP space gun can still be reached along the Barbados coast.