“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)

Onlookers gather around a struggling beached whale in the Yoff neighborhood of Dakar, Senegal Wednesday, May 21, 2008. Residents worked Wednesday morning to save some of the more than 80 whales that were stranded on the beach Tuesday night. This whale was successfully towed out to sea by a fishing boat, though at least 20 others lay dead on the beach by midday Wednesday. (Photo by Rebecca Blackwell/AP Photo)

Vitoria Bueno, a 16-year-old dancer whose genetic condition left her without arms, poses for a picture in her neighborhood in Santa Rita do Sapucai, Brazil, February 7, 2021. (Photo by Ueslei Marcelino/Reuters)

A woman holds her dog after arriving from Russian-occupied territory at a registration and processing area for internally displaced people in Zaporizhzhia, in Ukraine, on May 8, 2022. (Photo by Dimitar Dilkoff/AFP Photo)

A brown bear cub by the Khailyulya River in north-east Kamchatka, Russia on July 24, 2021. (Photo by Yuri Smityuk/TASS)

A schoolgirl walks on an under-construction railway track at Navapura, on the outskirts of Ahmedabad, November 29, 2019. (Photo by Amit Dave/Reuters)

This photo taken on March 3, 2020 shows a tattooed Chin ethnic woman smoking at her house decorated with animal skulls in a village of Chin State, western Myanmar. (Photo by Sai Aung Main/AFP Photo)

People ride a minibus illuminated with green colorful lights at a street in preparation for celebrations of the birthday of the prophet Muhammad, in Sana'a, Yemen, 04 October 2022. Mawlid is annually celebrated by many Muslim countries on the 12th day of Rabi al-Awwal (the third month of the Islamic calendar), marking the birthday of the prophet Muhammad, which is expected to be marked on 08 October 2022. In Yemen, it is celebrated by illuminating buildings and streets with green colorful lights and decorating vehicles in green. (Photo by Yahya Arhab/EPA/EFE)