Even the healthiest astronauts could suffer cardiac arrest due to the harmful nature of space itself. But CPR as we know it on Earth isn't possible on the space station because it's missing one key ingredient: gravity. Complex medical procedures haven't taken place on shuttle missions or the space station yet. When Mark Kelly was on Earth and his twin, Scott, spent a year on the space station, they were able to overcome the slight delay to talk every day. Unlike in an ambulance or an operating room, supplies for medical procedures and emergencies are stored in multiple areas and lockers.

Source: CNN June 21, 2017 08:37 UTC