Currently, doing laundry in microgravity is an unsolved engineering problem. The result is that clean clothes on the International Space Station have become a consumable resource. Clean clothes get launched to the space station regularly. When they are too dirty to wear, they just get stuffed into a used cargo capsule as trash.
For a more long-term mission where supply flights are not an option, like a manned Mars mission for example, this would be a problem. Shipping enough clothes for 9 months (even more when you don't want to wash clothes while staying on the Mars surface) would require quite a lot of valuable payload capacity.
But what about the simplest solution: Just don't wear any clothes. Human body hygiene in space is a solved problem. When astronauts stay nude during most of their intra-vehicular activities, the need for fresh clothes could be drastically reduced.
- The astronauts are in a controlled environment, so protection from the weather is not required.
- The everyday clothes ISS astronauts are wearing aren't going to protect them against any of the dangers of space travel, so safety is not an argument either.
- The cultural stigma against nudity between the astronauts can be overcome. Nudist movements all around the world show that it is perfectly possible to have normal social interactions without wearing clothes.
- The modesty of the astronauts towards the general public can be preserved by not livestreaming the whole mission. The long transfer phases between Earth and Mars are boring anyway. Public interest in actually seeing the astronauts can be limited to the critical mission phases. But these would just be a tiny fraction of the overall mission time. The astronauts could get dressed just for these occasions.
Am I overlooking some problems which would arise if astronauts would not wear clothes at all times and which would outweigh the problems caused by managing laundry?