>Update to "The Sands of Mars"
>
>They have to make a course direction so as to land on Deimos rather than Phobos. They're annoyed because this will take the astrogator "hours of computing" to work out the new course. Note that the existence of an on-board computer hasn't even been mentioned yet so I assume he means with a slide rule and graph paper.

No, he means endless cranking of the computers, and assuming the cogs were made of good steel which would not break under the effort :).