Hugh Pickens writes writes: "Draining an infected abscess is a straightforward procedure on Earth but on a spaceship travelling to the moon or Mars, it could kill everyone on board. Now Rebecca Rosen writes that if humans are to one day go to Mars, one logistical hurdle that will need to be overcome is what to do if one of the crew members has a medical emergency and needs surgery. "Based on statistical probability, there is a high likelihood of trauma or a medical emergency on a deep space mission," says Carnegie Mellon professor James Antaki. It's not just a matter of whether you'll have the expertise on board to carry out such a task: Surgery in zero gravity presents its own set of potentially deadly complications because in zero gravity, blood and bodily fluids will not just stay put, in the body where they belong but could contaminate the entire cabin, threatening everybody on board. This week, NASA is testing a device known as the Aqueous Immersion Surgical System (AISS) that could possibly make space surgery possible. Designed by researchers at Carnegie Mellon and the University of Louisville, AISS is a domed box that can fit over a wound. When filled with a sterile saline solution, a water-tight seal is created that prevents fluids from escaping. It can also be used to collect blood for possible reuse. "You won't have a blood bank in space," says James Burgess who came up with the concept for AISS, "so if there is bleeding you want to save as much blood as you can.""