The U.S. Air Force is exploring the possibility of developing nuclear-armed intercontinental ballistic missiles (ICBMs) that are sub-based and launched from underground tunnels. This was reported by the American magazine Popular Mechanics, citing the report of the Federation of American Scientists.

In the first case, the ICBM is “enclosed in a waterproof capsule fixed to the bottom of a deep lake.” “As soon as the launch command is given, the capsule is released and guided to the surface, then the rocket engine is started and rises,” the publication says.

In the latter case, it was planned to build an underground tunnel network with railway tracks. “Missiles must traverse a rail system on ramps and break the ground upward in the event of an attack,” the publication said.

Popular Mechanics notes that such ideas have been abandoned because of the financial, technological, and environmental challenges of their implementation. The publication writes that the land-based LGM-35A Sentinel ICBM created in the USA will be launched from the same installations as the LGM-30G Minuteman III.