How do astronauts function in their space suits for hours at a time?

Astronauts who spacewalk outside the space shuttle and International Space Station can work for up to 7 hours in the current space suit, which is also called the Extravehicular Mobility Unit (EMU). The EMU is a marvel of technical achievement with a $12 million price tag. Despite the advanced technology of the EMU, the “mechanics” used to meet the astronaut’s basic needs of food, water, and waste elimination are surprisingly “low tech.”

Eating
There is a slot in the hard upper torso (HUT) portion of the EMU for a rice paper-covered fruit and cereal bar. The bar is designed so that the astronaut can take a bite and pull the remainder up. The entire bar must be eaten at once to prevent crumbs from floating within the helmet. However, most astronauts prefer to eat prior to the spacewalk and not use this bar.

Drinking
The space suit has the In-suit Drink Bag (IDB), which is a plastic pouch mounted inside the HUT. The IDB can hold 32 ounces or 1.9 liters of water and has a small tube (straw) that fits up next to the astronaut’s mouth. The astronaut can move his/her head within the helmet and suck water through the tube.

Eliminating Waste
Each spacewalking astronaut wears a large, absorbent diaper called a Maximum Absorption Garment (MAG) to collect urine and feces while in the space suit. The astronaut disposes the MAG when the spacewalk is over and he/she gets dressed in regular work clothes.