A program error and 48 orbits

During the flight it emerged that Tereshkova did not feel well in weightlessness — she suffered from nausea and fatigue. Even so she stayed in space longer than all of America's Mercury astronauts combined, completing forty-eight orbits of the Earth.

A more serious problem showed up in the guidance program: the capsule was set so that instead of descending it would drift away from Earth. Tereshkova spotted the error on the first day and Mission Control uploaded corrected data that fixed the ship's orientation. She later said it was the unpalatable food rather than weightlessness that had made her feel ill.