For the Mars Medical Challenge, my device, H2O, is a gravity water filter which turns used water into purified useable water. It can be used for drinking water, plants, water for bathing, etc. It works by taking off the lid and pouring your used water in. There will be a drain which will catch any big items like rocks, as the water seeps through it will go through gravel and sand until it reaches another drainer (with smaller holes to catch any gravel that want to go with). Then into a dripper, where water will drip through a coffee filter into the purified water bucket. There will also be a spigot to let out the water, to go in your bucket. H2O is light gold and comes with the drainers and lid on the side, not included in the device itself (this is so it can be cleaned out). It is made out of PLA plastic when it is 3-D printed and also doesn’t include gravel, sand, or coffee filters, the astronauts must either bring it with them or get it from Mars.