tc (02/20/83)
The 18 Feb issue of SCIENCE magazine has an article by Edward Hutchings, Jr. called The Autonomous Viking. Here is the summary: The two Viking spacecraft launched to Mars in 1975 were designed for 90 days of intense observations followed by an extended mission phase to end in 1978. Because the spacecraft were still operating so well in 1978, three more mission phases were added and the project was not officially terminated until 1980. During these last three mission phases delays in controlling the orbiters from the earth increased. The spacecraft were kept functional and the length of the Viking mission was extended because the ground crew, over a period of 2 years, gradually made the orbiters autonomous. I have often been amazed at the way controllers have been able to extend the operation and capabilities of US spacecraft. This is yet another example. Tom Crawford ...decwrl!amd70!tc