Before Elon Musk, Jeff Bezos and other space enthusiasts can ship humans to Mars as easily as an Amazon Prime delivery, we need to figure out they will fare on a foreign planet. Luckily, NASA and the University of Hawaii have been all over this, funding several successful iterations of an experiment called Hawaii Space Exploration Analogue and Simulation (HI-SEAS), in which a crew of "astronauts" live in Mars-like conditions in a dome on a Hawaiian volcano. On Sunday, the fifth Hi-SEAS endeavour ended, meaning a crew of six "astronauts" have left the comfort of a literal bubble to greet the fresh hell that is Earth right now.