“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 female pitch invader is caught by a steward during Day Two of the Fourth Test between South Africa and England at Wanderers on January 25, 2020 in Johannesburg, South Africa. (Photo by Stu Forster/Getty Images)

South Korean youths dance to electronic music during the Ultra Music Festival Korea at Olympic Stadium on June 10, 2016 in Seoul, South Korea. (Photo by Jean Chung/Getty Images)

South African surfer Andy Marr rides a wave at Dungeons offshore reef in the Atlantic Ocean outside Cape Town, South Africa, 01 September 2016. The big wave surfing season is at its peak with winter swells driven by storms in the South Atlantic breaking on the Cape's outer reefs providing good conditions. Big wave surfers are competing in the 2016 Striped Horse Challenge and Rebel Sessions big wave competitons symultaneously throughout the season. (Photo by Nic Bothma/EPA)

South Korean girl group KARA arrive during the 21st High1 Seoul Music Awards at Olympic gymnasium on January 19, 2012 in Seoul, South Korea. (Photo by Chung Sung-Jun/Getty Images)

South Korean college students wearing masks hold up candles as they march after a rally calling for South Korean President Park Geun-hye to step down in Seoul, South Korea, Saturday, November 12, 2016. Hundreds of thousands of people flooded Seoul's streets on Saturday demanding the resignation of Park amid an explosive political scandal, in what may be South Korea's largest protest since it shook off dictatorship three decades ago. (Photo by Lee Jin-man/AP Photo)

Michael Bath, from McLeans Ridges in New South Wales, Australia, estimates that in his lifetime he has taken more than 3,500 images of lightning bolts illuminating the sky. Photo: Alstonville, New South Wales, Australia – January 8, 2003. (Photo by Michael Bath/Caters News)

South Korean singer CL performs during the closing ceremony of the 2018 Winter Olympics in Pyeongchang, South Korea, Sunday, February 25, 2018, after 17 days of hard- fought competition. Olympic fire went out. (Photo by Natacha Pisarenko/AP Photo)