“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)

A walrus kisses a visitor during a sea animal show at the Hakkeijima Sea Paradise aquarium-amusement park complex in Yokohama, southwest of Tokyo, Monday, September 11, 2017. (Photo by Shizuo Kambayashi/AP Photo)

Members of the Women's Organization to War on Styles (WOW) picket a dress shop in Berkeley, Calif., August 23, 1947, in protest to longer skirts and padded hips. They are the wives of GI students at the University of California. Left to right: Jackie Houser; Wanda Ames; Dorothy Inman; Terry Ligon; Ruth Van Arkel; Carrol Reynolds, and Barbara Carmichael. (Photo by AP Photo)

Victorious in 129 successive fights, including 40 as a pro, Ray Robinson falls through the ropes of a ring, under the impact of Jake LaMotta's fists on Olympia Stadium, Detroit, Michigan on February 5, 1943. Robinson got back in the ring, but lost the decision in ten rounds. LaMotta pummelled him for the rest of the fight, winning via a unanimous decision, giving Robinson the first defeat of his career.They fought again just 21 days later when Robinson regained his mantle winning in another 10-round fight, Robinson won the close fight by a unanimous decision. LaMotta stated the bout was gifted to Robinson because he would be inducted into the army the next day. (Photo by Bettmann Archive/Getty Images)

The UK reality TV mum Binky Felted out and about in London, England on November 7, 2017. Binky looked amazing in a black blazer, (Photo by Flynet Pictures)

Revelers celebrate during fireworks marking the start of the New Year on Copacabana beach on January 1, 2017 in Rio de Janeiro, Brazil. (Photo by Mario Tama/Getty Images)

British theoretical physicist Stephen Hawking, Cambridge University Professor and Fellow, circa 1985. Stephen Hawking, the brightest star in the firmament of science, whose insights shaped modern cosmology and inspired global audiences in the millions, has died aged 76. (Photo by Gemma Levine/Getty Images)

A stroller walks his dogs in an autumnally colored forest in Cuxhaven, nothern Germany on November 7, 2018. (Photo by Patrik Stollarz/AFP Photo)