The second question:
In space, due to physical floating and psychological factors, many astronauts have the experience of being unable to solve the problem of defecation. When training on the ground, astronauts should overcome great psychological obstacles, sit, lie or even change their posture in the horizontal cabin, and conduct defecation training in bed. Before going to the toilet, you should fix your shoes and lower body, grasp the handrails on both sides of the toilet with both hands, and the most important thing is that your hips must be close to the edge of the toilet, so that the inside of the toilet is completely sealed from the outside, so as not to let the urine float out of the toilet.
At present, the toilets in use on the International Space Station store urine in a 20-liter container and regularly discharge it into space, or pour it into the Russian "Progress" supply spacecraft when it is full, and then enter the earth with it, and it will be rubbed and burned when crossing the atmosphere. The feces are compressed and dried, then temporarily stored in a collection tank, and then brought back to Earth by the supply space shuttle for treatment.
What astronauts eat and mental adjustments are all ways to reduce defecation, so similar situations rarely happen in space.
Answer over