11th Security Forces Squadron response force members Senior Airmen Aaron Legardye, left, and Anthony Poindexter participate in a land navigation exercise during the 11th SFS Defender’s Challenge on Joint Base Andrews, Md., Oct. 3, 2018. The challenge tested defender’s physically, as well as mentally, in weapons knowledge, urban tactics, land navigation, self-aid buddy care and response to attack. (U.S. Air Force photo by Airman 1st Class Michael S. Murphy)