By Alfredo Diaz
On February 10, 2009, the first accidental hypervelocity collision between two intact artificial satellites in low Earth orbit occurred when Iridum 33, a 1,234 pound satellite, and Kosmos-2251, a 1,984 pound satellite, collided as they passed over northern Siberia at an altitude of 490 miles, traveling at around 26,170 miles per hour, producing almost 2,000 pieces of debris larger than 4 inches in diameter, and more than 200,000 smaller pieces. A 0.5 mm paint chip traveling at 35,000 km/hr (10km/sec) could puncture a standard space suit; a one-centimeter fragment could damage a space station.
According to the 1972 Liability Convention, liability for these fragments depends on the Launching State and whether damage occurred in orbit. If the object causes damage to the surface of Earth or and aircraft in flight, a strict liability standard applies—a state is considered strictly liable for any damage caused by a space object launched even in the face of circumstances that are outside of its control. If the space object causes damage some place other than the surface of Earth, a fault standard is applied.
How this all plays out, we do not truly know. The Liability Convention has also never been formally invoked—all incidents to date that could have resulted in potential claims under the Convention, including the Iridium-Cosmos collision, have been settled by the respective countries outside of the Convention. Still, someone will have to clean all of this up— international space law deems fragments and components from space objects as individual space objects in and of themselves, requiring identification to determine the owner and either individual or blanket consent to remove it from orbit, as there is no right of salvage analogous to the right in maritime law.