Nukes in Space

High-altitude nuclear explosions (HANE) have historically been nuclear explosions which take place above altitudes of 30 km, still inside the Earth atmosphere. Such explosions have been tests of nuclear weapons, used to determine the effects of the blast and radiation in the exoatmospheric environment. The highest was at an altitude of 540 km (335.5 mi).

The only nations to detonate nuclear weapons in outer space are the United States and the Soviet Union. The U.S. program began in 1958 with the Hardtack Teak and Hardtack Orange shots, both 3.8 megatons. These warheads were initially carried on Redstone rockets. Later tests were delivered by Thor missiles for Operation Dominic I tests, and modified Lockheed X-17 missiles for the Argus tests. The purpose of the shots was to determine both feasibility of nuclear weapons as an anti-ballistic missile defense, as well as a means to defeat satellites and manned orbiting vehicles in space. High-altitude nuclear blasts produce significantly different effects. In the lower reaches of vacuous space, the resulting fireball grows much larger and faster than it does near the ground, and the radiation it emits travels much farther.

During the heart of the Cold War, the United States and the former Soviet Union launched and detonated a combined total of over 20 thermo nuclear weapons in the upper atmosphere and near space region of earth in an effort to test the effects of launching an offense as well as countering an offense.

Almost unknown to the public, much of the information on theses tests has been kept secret for over 35 years until recently, when newly declassified test footage and secret government documents obtained from both countries reveals everything from the ICBM to outer space testing to ABM.