Fish could complete the perfect space ship Preeda Soyraya/EyeEm/Getty
Fish may be key to sustaining people on a long space mission. A well-stocked aquarium could provide enough extra nutrients to feed the astronauts’ crops, while also offering a source of protein.
The ideal spaceship is a closed system, where those on board can grow everything they need to survive and all waste is processed for reuse. On the International Space Station, for example, urine is collected and processed so that it is safe to drink.
For growing crops, one approach would be to use human waste as a…
