The Northrop P-61 Black Widow had a gun mounted that was designed by whom?
M2 Browning The M2 Machine Gun or Browning .50 Caliber Machine Gun is a heavy machine gun designed toward the end of World War I by John Browning. Its design is similar to Browning's earlier M1919 Browning machine gun, which was chambered for the .30-06 cartridge. The M2 uses the much larger and much more powerful .50 BMG cartridge, which was developed alongside and takes its name from the gun itself (BMG standing for "Browning Machine Gun"). It has been referred to as "Ma Deuce", in reference to its M2 nomenclature. The design has had many specific designations; the official designation for the current infantry type is Browning Machine Gun, Cal. .50, M2, HB, Flexible. It is effective against infantry, unarmored or lightly armored vehicles and boats, light fortifications and low-flying aircraft. The M2 has been produced longer than any other machine gun.
Black Horse (rocket) The Black Horse was a study concept for a proposed winged single-stage to orbit spaceplane that would use aerial refueling to greatly reduce the size of the spacecraft, to about the size of an F-16 Fighting Falcon. The original concept was proposed in 1993 by US Air Force Captain Mitchell Burnside Clapp, who was familiar with the Air Force's use of aerial refueling to extend the performance of combat aircraft. The concept was further developed by others, including an even smaller concept developed by Robert Zubrin, Black Colt. Clapp left the Air Force in 1996 and partnered with Zubrin to form Pioneer Rocketplane, who proposed a slightly larger version known as Pathfinder. This has since become the Pathfinder XL concept.