Los Alamos National Laboratory

Los Alamos National Laboratory

Delivering science and technology to protect our nation and promote world stability

The MX Factor

Data from atmospheric test films persuaded Department of Defense planners not to deploy the MX missile system in the Great Basin Desert.
July 1, 2015
The MX Factor

A Peacekeeper test missile re-entering the atmosphere at the Kwajalein Atoll in the Marshall Islands. This long-exposure photo shows the paths of the multiple re-entry vehicles deployed by the missile. (Photo: U.S. Army)


  • Managing Editor
  • Clay Dillingham
  • Email
The atmospheric test films showed why the MX missiles should not be based in the Great Basin Desert.

The United States developed the MX missile system in the early 1980s expecting they could survive a first strike by the Soviet Union. Military strategists planned to secure the missiles in hardened concrete shelters scattered around the hot, wide-open desert of the Great Basin in Utah and Nevada.

Then they considered data derived from atmospheric test films, where they were surprised to find something called a thermal precursor: an extra shock wave. In hot, dry environments, this shock wave raced ahead of the main shock wave, inflicting additional heavy damage on anything in its path. That was enough to persuade planners not to deploy the MX missile in the desert.