One kilogram of carcinogenic plutonium-238 was dispersed in the Earth’s atmosphere. It turned out that virtually the entire surface of the globe was affected by this pollution.
On this day the American nuclear powered navigation satellite burned down in the Earth’s atmosphere, scattering radioactivity in the air. It was a Transit-5BN-3 satellite, which was part of the American Transit system (known as the first satellite navigation system in world history in general). This system was funded by the U.S. Navy and its primary role was to provide accurate navigation information for the nuclear submarines that could target the USSR with Polaris missiles.
Transit-5BN-3 was powered by a special nuclear device, which contained about one kilogram of radioactive plutonium-238. That was actually not a nuclear reactor in terms of those that run nuclear power stations, but the so-called radioisotope thermoelectric generator. In such devices, the radioactive decay of plutonium is used to produce electricity by using the so-called “Thermoelectric effect”. Unlike nuclear reactors, these devices are much more compact and can be easily installed in satellites. It is important to emphasize that there is no nuclear fission in radioisotope thermoelectric generators (unlike in nuclear reactors). They are used where a considerable length of power generation is required.
Satellite Transit-5BN-3 with a radioisotope thermoelectric generator type SNAP-9A was launched on this day from California by the Thor Ablestar rocket, but failed to enter orbit around the Earth. It fell apart somewhere over the island of Madagascar, at an altitude of about 46,000 m (in the stratosphere). One kilogram of carcinogenic plutonium-238 was dispersed into the Earth’s atmosphere. Of course, plutonium-238 is a highly carcinogenic material.
The Americans did some tests to see where the radioactive material dispersed after the disaster. It turned out that virtually the entire surface of the globe was affected by this pollution. It is interesting that about one quarter of the radioactivity ended up in the northern hemisphere, despite the destruction of the satellite over distant Madagascar.