The gun, which was inspired by the one that Batman carried, is able to launch a grappling hook up to 90 feet in the air; an automated pulley system then carries the operator to the top.
Under the terms of the contest the team has 20 minutes to demonstrate a tool that is able to carry three people, each carrying 300 pounds of gear, to the top of a 90-foot vertical incline. The video below shows the grappling gun in action as it pulls a student up at a rate of 30 feet per minute.
After watching the video, I’ve got to say that 30 feet per minute is far less impressive than it sounds. Seriously, their grappling hook gun is awesome and everything, but I’m pretty sure I’ve seen paint dry at 30 feet per minute – I hope the Air Force doesn’t plan on using it in a combat scenario because anyone on the end of that thing will be riddled with bullets long before they get even half way up – just keeping it real folks, just keeping it real. [Source]