First there is the problem of radioactivity being spread if there is a blow-up on launch. First there is the problem of radioactivity being spread if there is a blow-up on launch. January's explosion on launch of a Delta II rocket at the Kennedy Space Center in which Florida residents as far off as Vero Beach, l00 miles away, were told to remain indoors to avoid falling debris after that mishap is an example of what could occur with a Cassini launch accident. Plutonium has long been described by scientists as the most toxic substance known. One pound, if uniformly distributed, could hypothetically induce lung cancer in every person on Earth.
Propulsion is to be provided by a traditional chemical source.
But there is insufficient propulsion to get Cassini directly from Earth to its final destination, Saturn. The Cassini probe is supposed to buzz the Earth in August 1999 at 42,300 miles per hour and be just 312 miles high. But if after a billion miles in space there is a miscalculation and Cassini comes in too close it could burn up in the 75-mile high atmosphere, dispersing plutonium widely back on Earth. But if after a billion miles in space there is a miscalculation and Cassini comes in too close it could burn up in the 75-mile high atmosphere, dispersing plutonium widely back on Earth. This thing, coming down into the Earth's atmosphere, will vaporize, release the payload and then particles of plutonium dioxide will begin to rain down on populated areas, if that is where the system is going to be hitting.