A two-horse team street cleaner, with sprayer, squeegee, and roller at rear. New York, between ca. 1910 and ca. 1915. (Photo by NYC Municipal Archives)

Runners rest inside Kim Il Sung Stadium in Pyongyang, North Korea on Sunday, April 14, 2013. North Korea hosted the 26th Mangyongdae Prize Marathon to mark the upcoming April 15, 2013 birthday of the late leader Kim Il Sung. (Photo by Alexander F. Yuan/AP Photo)

Competitors line up their boats for some formalities during the Aberdeen Dragon Boat Races. (Photo by Jessica Hromas)

A member of the mainly Christian “anti-balaka” (anti-machete) militia trains in the Boeing neighbourhood of Bangui, Central African Republic, on February 24, 2014. (Photo by Fred Dufour/AFP Photo)

Two male African mantis Pseudempusa pinnapavonis (Peacock Mantis) show their colours in Igor's home studio in Munich, Germany. (Photo by Igor Siwanowicz/Barcroft Media)

Jesse Tyler Ferguson photobombs Miranda Kerr and Orlando Bloom at the 2013 Vanity Fair Oscar party. (Photo by Jon Kopaloff/FilmMagic)

Xie Guobiao (C), 11, tied to a pillar with a rope, cries as his grandmother (L) and younger sister look on at his home in Daohui village of Lishui, Zhejiang province May 7, 2014. Xie was diagnosed as mentally handicapped when he was young, but the family was not able to provide him with sufficient medical treatment because of poverty. At the age of six, Xie started to sneak out of his home when others were not looking, climbing on top of houses and smashing windows. Xie's family had to pay over 10,000 yuan ($1,606) in compensation to others for the damage he caused. Since then, the family has had to tie Xie up with a rope both at home and in public, they said. (Photo by William Hong/Reuters)

“Wernher Magnus Maximilian Freiherr von Braun (March 23, 1912 – June 16, 1977) was a German-born rocket scientist, aerospace engineer, space architect, and one of the leading figures in the development of rocket technology in Nazi Germany during World War II and, subsequently, the United States”. – Wikipedia

Photo: German-born American engineer Dr. Wernher von Braun with a model of the Explorer orbiting space satellite which he designed. (Photo by Keystone/Getty Images). 1958