How do astronauts go to the bathroom in space?

In microgravity, toilets cannot rely on gravity to move waste away, so spacecraft use fans and airflow to guide it. Urine is typically collected through a funnel or hose, while solid waste is captured by a seat with suction and sealed containers. On the International Space Station, urine is processed and much of the water is recycled into clean drinking water. Earlier spacecraft had much simpler systems, but long-duration missions need efficient recycling to conserve supplies. Toilet design is a serious engineering challenge because hygiene, odor control, and reliability all matter in orbit.