The Vietnam Slide Project was created by photo editor Kendra Rennick, who began collecting photo slides after a close friend lost her father, a Vietnam veteran. Her friend found a box of slides that her father had taken while in Vietnam and from there Rennick has continued to collect photographs that Vietnam veterans took during their tours of duty. Here: A photo taken from the collection of D.Thornton, who served in the First Air Cavalry division of the United States Army. (Photo by D.Thornton/The Vietnam Slide Project)

An Afghan National Army (ANA) soldier assigned to the Mobile Strike Force Kandak fires a RPG-7 rocket-propelled grenade launcher during a live-fire exercise supervised by the Marines with the Mobile Strike Force Advisor Team on Camp Shorabak, Helmand province, Afghanistan, May 20, 2013. The Marines with the Mobile Strike Force Advisor Team instructed and mentored their ANA counterparts on how to properly utilize their weapons systems. (Photo by SSgt Ezekiel R. Kitandwe/RCT 7)

Bicycle rickshaw drivers chat as they wait for customers near the Drum Tower in a traditional neighbourhood on September 30, 2021 in Beijing, China. China will mark National Day and the Golden Week holiday from October 1st. (Photo by Kevin Frayer/Getty Images)

An Airbus A400M military aircraft lands at the ILA Berlin Air Show in Schoenefeld, south of Berlin, Germany, June 1, 2016. The Aerospace Exhibition at Schoenefeld Airport near Berlin takes place from June 1 till 4. (Photo by Fabrizio Bensch/Reuters)

Brazilian model Sofia Resing arrives for the screening of the film “France” at the 74th edition of the Cannes Film Festival in Cannes, southern France, on July 15, 2021. (Photo by Sarah Meyssonnier/Reuters)

Portuguese model Sara Sampaio attends the screening of “Elvis” during the 75th annual Cannes film festival at Palais des Festivals on May 25, 2022 in Cannes, France. (Photo by Stephane Cardinale – Corbis/Corbis via Getty Images)

Operations & Exercises, 1st place. An RAF Voyager aircraft sits in the harsh winter weather at Mount Pleasant Complex, Falkland Islands, while personnel work to ensure the snow is cleared. (Photo by Sgt Andy Holmes/2020 RAF Photo Competition)

Shocking footage of a low-altitude flight through Brisbane's skyscrapers in United Kingdom on Thursday, September 23, 2021. The Royal Australian Air Force C-17 cargo jet was spotted on a practice run ahead of the annual Sunsuper Riverfire event, which took place on Saturday night. (Photo by The Mega Agency)