"fly"

It happens to be the season when mosquitoes and flies go wild, but it is true that there are not as many flies as there are mosquitoes today. This has a lot to do with our improved sanitation today, after all, flies need to lay their eggs on manure pits and rotting food, while many rural toilets have now been converted to squatting, and the shorter disposal cycle for waste has greatly reduced their hatching.

In orbit for longer and longer periods of time, we need to solve not only inorganic resupply problems such as food, water, oxygen and propellant, but also the various problems faced by astronauts flying in orbit for long periods of time