Becoming an Astronaut is a big deal! Men and women selected to go into space are very carefully chosen. They go through rigorous medical evaluations to make sure they are healthy and that their bodies can withstand the forces of liftoff and re-entry. And they go through months and months of training to prepare them for their first space flight. Now NASA is sending untested, untrained astronauts into space. Of course, they are not human, they are fruit flies!
Fruit flies are bug eyed and spindly, they love rotten bananas, and, following orders from their pin-sized brains, they can lay hundreds of eggs every day.

We have a lot in common.

Genetically speaking, people and fruit flies are surprisingly alike, explains biologist Sharmila Bhattacharya of NASA’s Ames Research Center. “About 77% of known human disease genes have a recognizable match in the genetic code of fruit flies, and 50% of fly protein sequences have mammalian analogues.”