Originally Posted by Platapus

The United States takes great measures to ensure that our nuclear weapons can not be launched by unauthorized personnel.

Starting in the 1960's, SecDef McNamara instigated a system of Technical Locks which were physical locks that would prevent a nuclear weapon from being activated. Due to security there was a complicated system where these combinations would be updated and changed. These combinations are totally separate from launch authorization codes

This bothered General Thomas Powers (CINCSAC) among others that this new security practice might result in confusions and in the worse case scenario prevent the authorized use of nuclear weapons.

So, working against policy, the Technical Lock out combinations for all the LGM30 Minuteman ICBMs were set to 00000000

There are multiple articles on the Internets Tubes that claim this to be the actual launch code, but it wasn't. It was a technical lock out code.

The Technical lock out code was not used to launch the missile it was used to prevent the launch of the missile.

But still, eight zeros, who would have thought?