The First U.S. Spacewalk – Gemini 4 Ed White made the United States' first spacewalk on June 3, 1965 during the Gemini 4 mission. The extra-vehicular activity (EVA) started at 19:45 UT (3:45 p.m. EDT) on the third orbit when White opened his hatch and used the hand-held manuevering oxygen-jet gun to push himself out of the capsule. (Photo by NASA)

The Enemy, 1944. With the outbreak of world war two, photojournalism was enlisted in defence of Mother Russia. In this photo by Anatoli Egorov, who was wounded in action, corporal Stepan Vasiljevich Ovcharenko shoots at enemy troops with a machine gun. (Photo by Anatoli Egorov/Lumiere Brothers Center for Photography)

Deputies of the opposition fight with deputies of the majority for a second time in two days, during the second session of the newly elected Ukrainian parliament in Kiev on December 13, 2012. (Photo by Sergei Supinsky/AFP Photo)

Workers clad in a dog and a wild boar costumes, to represent the outgoing year of the dog and incoming year of the wild boar, clean windows on the side of a hotel in Tokyo on December 13, 2018. (Photo by Kazuhiro Nogi/AFP Photo)

People on inflatable boats enjoy the weather on the Lake Lucerne in Sisikon, Switzerland, August 5, 2018. (Photo by Denis Balibouse/Reuters)

Bo, a 55-day-old baby Echidna known as a puggle, rests in the hands of vet nurse Annabelle Sehlmeier at Taronga Zoo in Sydney November 1, 2012. The puggle was brought to the zoo after it being found by itself on a walking track north of Sydney and will be fed by hand until it is weaned at about six months of age. (Photo by Tim Wimborne/Reuters)

A comedic photo of a cheetah appearing to find something hilarious by Dutton Robert for the Comedy Wildlife Photo Awards 2016, South Africa, April, 2012. (Photo by Dutton Robert/Barcroft Images/Comedy Wildlife Photo Awards)

A “nail house”, the last building in the area, sits in the middle of a road under construction in Nanning, Guangxi Zhuang Autonomous Region April 10, 2015. According to local media, the owner of the house didn't reach an agreement with the local authority about compensation of the demolition. (Photo by Reuters/Stringer)