The article 'an inexpensive solution.

• Author: Capon, Leonard E.

For Quickly Launching Military Satellites Into Space" was particularly significant because apart from the High Altitude Research Project (HARP) it drew attention to Gerald Bull and his work.

First however, the precise 4,265 feet per second velocity quoted is low. According to the Artillery Ammunition Manual TM43-0001-28 the tang gun M256 fires the M829 APFSDS-T projectile at a velocity of 5,510 feet per second. The HARP program produced much higher muzzle velocities.

I have a copy of the Bull and C. H. Murphy book, Paris Kanonen-The Paris Guns (Willhelmgeschutze and Project Harp: the Application of Major Caliber Guns to Atmospheric and Space Research). The first part of the book analyzes the firing of the 21-centimeter guns, which bombarded Paris from around 70 miles in World War I. These were 38 centimeter and 35.5-centimeter railroad guns fitted with extended 21-centimeter barrel liners and were probably the first guns in service to have a muzzle velocity of 5,000 feet per second. Bull denied that these guns inspired him to modify the 16-inch guns and smaller calibers in a similar manner for use in the HARP program. World War II...