NASA is developing a new spacesuit for the first time in 40 years. It's being built for the upcoming Artemis program, with NASA planning to send the next astronauts to the moon by 2024. But before it's flight ready, the Exploration Extravehicular Mobility Unit, or xEMU, must go through three stages of rigorous development and testing, including underwater adventures and temperature tests. Here's a look at how NASA tests its spacesuits.