This undated image provided by World View shows World View capsule and balloon spacecraft that will rise to 100,000 feet above Earth for passengers to see the curvature of the planet and the blackness of space. Space tourism companies are employing designs including winged vehicles, vertical rockets with capsules and high-altitude balloons. While developers envision ultimately taking people to orbiting habitats, the moon or beyond, the immediate future involves short flights into or near the lowest reaches of space without going into orbit. (Photo by World View via AP Photo)

Throughout the course of the long war in Afghanistan, Coalition troops have relied on thousands of military working dogs to help keep them safe, and make their jobs easier. The dogs are trained to detect explosives, to find illegal drugs, to search for missing comrades, or target enemy combatants. Not only are they active on the front lines, but behind the lines they serve as therapy dogs, service dogs, and loyal companions. They also share the same risks as the ground troops, suffering injuries and sometimes death on the battlefields. Gathered here are images of these dogs and their handlers in Afghanistan and back home, from over the past several years, part of the ongoing series here on Afghanistan.

Number 10. BELL H-13 SIOUX was a two-bladed, single engine, light helicopter built by Bell Helicopter. Westland Aircraft manufactured the Sioux under license for the British military as the Sioux AH.1 and HT. In 1947, the United States Air Force ordered the improved Bell Model 47A. Most were designated YR-13 and three winterized versions were designated YR-13A. The United States Army first ordered Bell 47s in 1948 under the designation H-13. These would later receive the name Sioux. The Bell-built H-13 B is seen airborne in this April 29, 1951 photo. The helicopter is equipped with a 173 horsepower engine, cruises at 85 miles per hour, climbs 900 feet in a minute and has a service ceiling of 11,500 feet. (Photo by AP Photo)

Protesters begin to gather ahead of the UK Student Climate Network's Global Climate Strike at Millbank in London, England on September 20, 2019. (Photo by Gareth Fuller/PA Images via Getty Images)

A three-metre-tall painted bronze sculpture, Seated Man 2016, by the artist Sean Henry, is lifted into its new home on July 23, 2019 at Yorkshire Sculpture Park in Wakefield, England. (Photo by Christopher Thomond/The Guardian)

In this July 23, 2013 photo, sand fills an abandoned house in Kolmanskop, Namibia. Kolmanskop, was a diamond mining town south of Namibia, build in 1908 and deserted in 1956. SInce then, the desert slowly reclaims its territory, with sand invading the buildings where 350 German colonists and more than 800 local workers lived during its hay-days of the 1920s. (Photo by Jerome Delay/AP Photo)

A Maasai warrior makes the high jump, in which athletes must touch a high line with the top of their heads, at the annual Maasai Olympics in the Sidai Oleng Wildlife Sanctuary near to Mt. Kilimanjaro, in southern Kenya, Saturday, December 13, 2014. Maasai men and women from the Amboseli and Tsavo region compete for medals and prizes in the event which aims for a sports competition of Maasai skills such as running, jumping, and throwing, to replace lion-hunting as the traditional warrior activity. (Photo by Ben Curtis/AP Photo)