 In 2032 , a cheela develops the race 's first weapon and tactics while overcoming a dangerous predator . In November 2049 a human expedition to Dragon 's Egg starts building orbital facilities . The rest of the story , including almost the whole history of cheela civilization , spans from 22 May 2050 to 21 June 2050 . By humans ' standards , a " day " on Dragon 's Egg is about 0 @.@ 2 seconds , and a typical cheela 's lifetime is about 40 minutes . 
