A demonstration on March 15, 1922 on Palace Roof, 57th Street and 7th Avenue, showing the shellproof steel jacket. Leo Krause wearing the jacket, which weighs 12 pounds. Shots used, 38 and 45 calibre, at close range. (Photo by Bettmann Archive)

In a photo taken on July 29, 2018 instructor Kim Ju Yang (20) holds a North Korean- made assault rifle as she poses for a portrait at the Meari shooting range in Pyongyang. The Meari shooting range offers customers the opportunity to shoot a number of North Korean and foreign- made firearms, most of which have been modifed to fire .22 calibre ammunition costing one US dollar per round. (Photo by Ed Jones/AFP Photo)

A 2S5 Giatsint self- propelled gun fires during tactical exercises held by artillery detachments of the Russian Eastern Military District' s 5th Army at the Sergeyevsky training ground in Primorye Territory, Russia on March 21, 2017. Over 2500 servicemen practice combat skills received in 2017 winter training exercises. (Photo by Yuri Smityuk/TASS)

A .44 Colt Dragon with a traditional Cowboy's hat. This weapon was originally used in the Mexican War of 1846-8 and it is typical of the type used in the “Wild West” of America. (Photo by Orlando /Three Lions/Getty Images). Circa 1950

“NASA's Pathfinder, Pathfinder Plus, Centurion and Helios Prototype were an evolutionary series of solar- and fuel-cell-system-powered unmanned aerial vehicles. AeroVironment, Inc. developed the vehicles under NASA's Environmental Research Aircraft and Sensor Technology (ERAST) program. They were built to develop the technologies that would allow long-term, high-altitude aircraft to serve as “atmospheric satellites”, to perform atmospheric research tasks as well as serve as communications platforms”. – Wikipedia

Photo: The solar-electric Helios Prototype flying wing is flies over the Hawaiian islands of Niihau and Lehua during the first solar-powered test flight July 14, 2001 from the U.S. Navy's Pacific Missile Range Facility on Kauai, HI. The 18-hour flight was a functional checkout of the aircraft's systems and performance in preparation for an attempt to reach sustained flight at 100,000 feet altitude later in the summer. (Photo Courtesy of NASA/Getty Images)

Supporters of Ugandan President Yoweri Museveni celebrate his election victory in Kampala, Uganda February 20, 2016. Ugandan President Yoweri Museveni extended his 30-year rule on Saturday, winning an election that international observers said lacked transparency and his main opponent, who was placed under house arrest, denounced as a sham. (Photo by Goran Tomasevic/Reuters)

On August 31, 2012, a long filament of solar material that had been hovering in the sun's atmosphere, the corona, erupted out into space at 4:36 p.m. EDT. The coronal mass ejection, or CME, traveled at over 900 miles per second. The CME did not travel directly toward Earth, but did connect with Earth's magnetic environment, or magnetosphere, causing aurora to appear on the night of Monday, September 3. (Photo by NASA/GSFC/SDO via The Atlantic)

Seized plastic handguns which were created using 3D printing technology are displayed at Kanagawa police station in Yokohama, south of Tokyo, in this photo taken by Kyodo May 8, 2014. Yoshimoto Imura became the first man to be arrested in Japan for illegal possession of two guns he created himself using 3D printing technology, Japanese media said on Thursday. The 27-year-old, a college employee in the city of Kawasaki, was arrested after police found video online posted by Imura claiming to have produced his own guns. Gun possession is strictly regulated in Japan. Police raided Imura's home and found five guns, two of which could fire real bullets, Japanese media said. (Photo by Reuters/Kyodo)