“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)

Participants pose for photographs as they take part in a “Hat Walk” during London Hat Week in London, Britain on April 7, 2019. (Photo by Simon Dawson/Reuters)

Members of the Delirio dance company perform during the “Hechizo” (Spell) virtual show, inspired by the legend of the merry widow on Hallo​ween night, in Cali, Colombia, 31 October 2020. (Photo by Ernesto Guzman Jr./EPA/EFE)

People brave strong wind on the promenade of Victoria Habour as tropical cyclone Ma-on approaches Hong Kong, Wednesday, August 24, 2022. Tropical Storm Ma-on was gaining strength as it headed for Hong Kong and other parts of southeastern China on Wednesday after displacing thousands in the Philippines. (Photo by Anthony Kwan/AP Photo)

Visitors are seen inside a newly opened bookstore in Chongqing, China on January 29, 2019. Covering an area of 1,400 square meters, the Zhongshuge Bookstore in Chongqing attracts readers with its creative decor. (Photo by Reuters/China Stringer Network)

Dog walkers enjoy the early morning sunrise at Tynemouth Beach in North Tyneside, on the north east coast of England on Monday, February 7, 2022. (Photo by Owen Humphreys/PA Images via Getty Images)

In this June 23, 2015 photo, Ashaninka Indian beauty contestants pose for a photo with members of a visiting music group, hired to perform during the annual founding anniversary festivities, in Otari Nativo, Pichari, Peru. The contestants wear the simple brown dresses of the Ashaninka woman, their faces dotted in a traditional design with a red dye extracted from a spice called achiote. (Photo by Rodrigo Abd/AP Photo)

Natural world and wildlife shortlist. Lop Buri in Thailand is home to hundreds of macaques, which local residents consider to be disciples of the Hindu god Hanuman. While some people love them, others fear or even hate them. Despite the inconvenience they often cause, the macaques are generally respected and considered sacred. (Photo by Joan de la Malla/Sony World Photography Awards)