Debris Danger

NASA is studying the possible danger to other spacecraft posed by Tuesday's collision of an Iridium and a Russian satellite. The Iridium was still functional; the Russian was a derelict. Determining the risks of collision of additional spacecraft with pieces of debris could take several weeks.

Most at risk would seem to be Earth observation satellites, many of which orbit in the same general area of the collision; some orbits might go through the debris cloud. The Hubble Space Telescope, because of its size. is another possible problem. Of course, ISS is many times larger than Hubble, but its orbit is well inside where the collision took place.

Because orbital space is so vast, and any spacecraft, by comparison, is so tiny, the odds of debris hitting another craft are extremely low, but, as was dramatically demonstrated Tuesday, they are non-zero.