|RENDEZ-VOUS IN SPACE|

The American probes were right on time for their appointment with Saturn. With a difference of less than two seconds, and after a voyage of four years, Voyager 1 and Voyager 2 passed within 209 and 102 000 kilometers from the surface of the planet on November 13, 1980 and August 27, 1981. Prior to these probes, Pioneer 11, with much less on-board equipment, was the only one to have reached this area on September 1, 1979. In less than two years, these three objects radically changed the panorama of the planet. When Pioneer left the Earth, a debate was raging about whether Saturn had three or five rings. Three had been known for quite some time. However, at the time of making a special route correction that would have changed the distance from which the probe would have flown by the planet, some astronomers suspected that there was another ring inside, ring D, and outside, ring E, the three rings. No one knew exactly what they were made of. Some said they were mainly ice particles, others ice and dust, and still other fragments of rock covered with ice. There was not even any precise information about the total thickness of all the rings. In any case, it was decided not to take too many risks and to use a trajectory that would take Pioneer below the outer edge of the rings, allowing the probe to graze the southern hemisphere of the planet. Despite this precaution, a series of disturbances to the radio transmissions soon indicated that the antenna had probably "collided" with some microscopic ice particles: which also meant that Saturn's rings were perhaps more extensive than previously thought. Then, the pictures transmitted to the Earth, though not of the best quality, showed that there must be at least seven. But the real surprise would come from the Voyager probes.
The American probes were right on time for their appointment with Saturn. With a difference of less than two seconds, and after a voyage of four years, Voyager 1 and Voyager 2 passed within 209 and 102 000 kilometers from the surface of the planet on November 13, 1980 and August 27, 1981. Prior to these probes, Pioneer 11, with much less on-board equipment, was the only one to have reached this area on September 1, 1979. In less than two years, these three objects radically changed the panorama of the planet. When Pioneer left the Earth, a debate was raging about whether Saturn had three or five rings. Three had been known for quite some time. However, at the time of making a special route correction that would have changed the distance from which the probe would have flown by the planet, some astronomers suspected that there was another ring inside, ring D, and outside, ring E, the three rings. No one knew exactly what they were made of. Some said they were mainly ice particles, others ice and dust, and still other fragments of rock covered with ice. There was not even any precise information about the total thickness of all the rings. In any case, it was decided not to take too many risks and to use a trajectory that would take Pioneer below the outer edge of the rings, allowing the probe to graze the southern hemisphere of the planet. Despite this precaution, a series of disturbances to the radio transmissions soon indicated that the antenna had probably "collided" with some microscopic ice particles: which also meant that Saturn's rings were perhaps more extensive than previously thought. Then, the pictures transmitted to the Earth, though not of the best quality, showed that there must be at least seven. But the real surprise would come from the Voyager probes.