A kinetic bombardment or a kinetic orbital strike is the hypothetical act of attacking a planetary surface with an inert projectile, where the destructive force comes from the kinetic energy of the projectile impacting at very high velocities. The concept originated during the Cold War.
The typical depiction of the tactic is of a satellite containing a magazine of tungsten rods and a directional thrust system. When a strike is ordered, the satellite would brake[1] one of the rods out of its orbit and into a suborbital trajectory that intersects the target. The rod picks up speed as it approaches periapsis and the target due to gravity, picking up immense speed until it begins decelerating in the atmosphere and reaches terminal velocity shortly before impact. The rods would typically be shaped to minimize air resistance and maximize terminal velocity. In science fiction, the weapon is often depicted as being launched from a spaceship, instead of a satellite.
Kinetic bombardment has the advantage of being able to deliver projectiles from a very high angle at a very high speed, making them extremely difficult to defend against. In addition, projectiles would not require explosive warheads, and—in the simplest designs—would consist entirely of solid metal rods, giving rise to the common nickname “Rods from God”. Disadvantages include the technical difficulties of ensuring accuracy and the prohibitively high costs of positioning ammunition in orbit.
The Outer Space Treaty prohibits weapons of mass destruction in orbit or outer space. However, the Outer Space Treaty only prohibits nuclear, biological, and chemical weapons. Since the most common form of kinetic ammunition is inert tungsten rods, in most cases, kinetic bombardment remains legal.
I missed your reply before. Thanks! That is interesting and a bit scary.