Project Thor (Rods from God)

A kinetic bombardment or a kinetic orbital strike is the hypothetical act of attacking a planetary surface with an inert kinetic projectile from orbit (orbital bombardment), where the destructive power comes from the kinetic energy of the projectile impacting at very high speeds. The concept originated during the Cold War. Typical depictions of the tactic are of a satellite containing a magazine of tungsten rods and a directional thrust system. When a strike is ordered, the launch vehicle brakes one of the rods out of its orbit and into a suborbital trajectory that intersects the target. The rods would typically be shaped to minimize air resistance and thus maximize velocity upon impact.

The concept was originally developed by Jerry Pournelle in the 1950s while working at Boeing, and was later studied by the U.S. Air Force under various project names. Although researched during the Cold War and periodically proposed in subsequent military space doctrine documents, the system was never officially funded, built, or deployed. High launch costs of lifting heavy tungsten payloads into orbit and treaty restrictions on space weaponization have kept the project entirely theoretical.