The
Kinetic Harpoon is a
weapon used for
orbital bombardment in the
scifi book
Reality Dysfunction by
Peter F. Hamilton.
"Kinetic Harpoons were the Confederation Navy's standard tactical (non-radioactive) planetary surface assault weapon. A solid splinter of toughened, heat-resistant composite, half a metre long, needle sharp, guided by a cruciform tail, steered by a processor with preprogrammed flight vector. They carried no explosives, no energy charge; they destroyed their target through speed alone." (Quoted from Reality Dysfunction, pg 98, Warner Books Edition)
The book describes them as a silent rain of fire striking the ground at a speed too fast for human senses to follow causing massive damage, followed by a delayed sonic shockwave from their decent through the atmosphere.