Thank you Deidre. Much of the waste, such as urine for example, is constantly recycled and which are reused as water for them, believe it or not! Foodstuffs they don't cook, they have dehydrogenated food packs which are reconstituted before eating, then sucked by those astronauts through a straw, or squeezed out from those packs into their mouths. Much of the waste that can't be recycled is either left on board in sealed waster containers and simple left onboard, or brought back to Earth with them. As for the spacecraft's... well, we all know where they end up!