A three wheeled “cabin” scooter manufactured by German aircraft engineers Messerschmitt & Co at factories in Regensburg. (Photo by Hans Enzwieser/BIPs/Getty Images). 1955

“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)

Fabrice Monteiro travelled to the most polluted places in Africa and created terrifying characters who roamed their midst dressed in eerie debris. They are spirits, he says, on a mission to make humans change their ways. Informed by Africa’s environmental problems, Fabrice Monteiro’s photographs aim to highlight urgent ecological issues all over the world. His series “The Prophecy” is on show at Photo Basel 2017 until 18 June. (Photo by Fabrice Monteiro/Photo Basel 2017/Mariane Ibrahim Gallery/The Guardian)

A riot policeman watches as a police vehicle burns in Braamfontein, Johannesburg, South Africa, Tuesday, October 25, 2016. Rioters in South Africa set a police vehicle on fire Tuesday and stoned vehicles near a Johannesburg university that has been the scene of sometimes violent protests by students demanding free education. The violence broke out in streets near the University of the Witwatersrand at around the same time that student protesters met and marched off the campus, South African media reported. (Photo by Yeshiel Panchia/AP Photo)

A Russian Su-35S combat aircraft and a Tu-95ms strategic bomber fly in formation above a church during a rehearsal for the flypast, which is part of a military parade marking the anniversary of the victory over Nazi Germany in World War Two, in Moscow, Russia on May 4, 2022. (Photo by Maxim Shemetov/Reuters)

Family members and relatives of passengers on board the Twin Otter aircraft operated by Tara Air, weep outside the airport in Pokhara on May 29, 2022. A passenger plane with 22 people on board went missing in Nepal on May 29, the operating airline and officials said, as poor weather hampered a search operation. (Photo by Prakash Mathema/AFP Photo)

A Romanian honor guard soldier stands still as three military aircraft carriers are crossing the sky during a ceremony held at the Unknown Soldier Memorial, in Carol I Park, on the occasion of the Heroes' Day commemoration, in Bucharest, Romania, 10 June 2021. (Photo by Robert Ghement/EPA/EFE)