The signing of the Partial Nuclear Test Ban Treaty in 1963 and the Outer Space Treaty in 1967 prevented future exploration of the concept of detonating a nuclear device on the Moon . By this time both the United States and the Soviet Union had performed several high-altitude nuclear explosions , including those of Operation Hardtack I , Operation Argus , Operation Dominic I and II , and The K Project
Operation Hardtack I
Operation Hardtack I
Project A119