Lt. Col. Jeff Klosky, a 99th Expeditionary Reconnaissance Squadron U-2 mission pilot, receives 100 percent oxygen one hour before his flight April 19, 2014, at an undisclosed location in Southwest Asia. U-2 pilots receive the oxygen for approximately one hour to remove nitrogen and other gasses from the body to prevent decompression sickness.(U.S. Air Force photo byTech. Sgt. Russ Scalf/Released)
