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.
- Whoever said that women are the weaker sex never tried to wrest the bedclothes off one in the middle of the night
- Worry is the interest you pay, in advance, for a loan that you may never need to take out.