U.S. Army Spc. Emmanuel Elien, 440th Blood Support Detachment medical laboratory technician, prepares U.S. Army Sgt. Victor Martinez, 440th BSD blood operations NCOIC, to donate platelets at the Craig Joint Theater Hospital on Bagram Airfield, Afghanistan, Oct. 10, 2018. In order to extract platelets, a critical life-saving blood component, apheresis machines are used to draw blood and return the unused portions to the donor. (U.S. Air Force photo by Staff Sgt. Kristin High)