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I read this old short story in an anthology (about 25 years ago) but can't remember the title.
The plot was that human colonists/astronauts arrive at a planet inhabited by rather primitive aliens. Caught unawares, they were captured and became slaves and beasts of burden to the aliens.
Many generations passed and, with education forbidden, the human descendants have forgotten their technology and where they came from. But there are whispers that an abandoned spaceship near the village/city actually belongs to the humans, and not the alien masters.
After a rebellion, a small group of humans managed to get inside the spaceship. With the help of a nursery rhyme passed from generation to generation, they find and push a button for the auto-pilot and a button that activates a needle that sedates them and puts them in suspended animation.
The ship blasts off, with the hope that it finds its way back to Earth, then return to the alien planet to rescue the remaining human slave descendants.
Anyone remember this short story and the anthology it comes from?