Disposing of the body's waste is among the most fundamental of human activities that earthbound people generally do with ease, but things can be different in a low-gravity environment.

Such activity can pose major problems in places where gravity is weak, such as in the International Space Station (ISS), where the waste produced and the act of "going" could pose some hurdles.

European Space Agency (ESA) astronaut Samantha Cristoforetti has shed light on what many ordinary people have wondered about for quite some time now: how astronauts use the toilet in space.

In a video uploaded by the ESA on YouTube on Friday, Cristoforetti explained how astronauts like her use the space toilet, walking viewers through the elaborate lavatory onboard the ISS.

The Italian astronaut provided information about the devices that are involved and the procedures that are crucial to the two-step process that astronauts onboard the ISS go through when nature calls. "Number one" and "number two" involve the use of a small receptacle, a unit for recycling urine and a rubber suction hose.

Cristoforetti pointed out that, unlike on Earth, urine is recycled in the ISS to reduce the amount of water that is delivered to the station in low-Earth orbit, albeit it is clear that this involves a complex filtration and sanitation process before the water can be used again.

Astronauts go to the station's toilet cabin when they need to pee; they urinate into the rubber hose that has a suction for collecting urine. This helps, given how everything floats in such a weightless condition. The urine collected by the hose is then transported to the urine processing assembly (UPA) and is recycled into the water that astronauts can drink.

Cristoforetti likewise said that taking a space dump works in a similar manner. A suctioning hose is also used, but the feces are stored in a waste tank, which is changed once in 10 days depending on the size of the crew onboard the ISS.

"A fan creates suction to avoid smells and floating waste. Solid waste is stored and put in cargo ferries to burn up when the spacecraft leaves the Space Station," the description of the video reads.

Below is the YouTube video uploaded by the ESA where Cristoforetti can be seen showing viewers how astronauts onboard the ISS use the space toilet to dispose of their bodily wastes.