“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 table and chair the size of a house have been captivating visitors to north London's Hampstead Heath. The 30ft (9m) sculpture, The Writer, will be on Parliament Hill for four months before returning to Italy.

Two dogs sent into outer space by the Soviet Union after their safe return to earth. They spent 22 days in orbit. (Photo by Central Press/Getty Images). 22nd March 1966

U.S. Air Force pilots with the Thunderbirds perform the calypso pass maneuver in F-16 Fighting Falcon aircraft during a practice session prior to the Gunfighter Skies air show at Mountain Home Air Force Base, Idaho, September 19 and released September 24, 2014. (Photo by Tech. Sgt. Manuel J. Martinez/Reuters/US Air Force)

BERLIN, GERMANY - NOVEMBER 11: Sculptor Oleg Bessonov creates a rosette from clay at the Schlossbauhuette studio where a team of sculptors is creating decorative elements for the facade of the Berliner Schloss city palace on November 11, 2011 in Berlin, Germany. The Berliner Schloss was the residence of the Prussian Kaiser and was among the major architectural landmarks of Berlin until it was heavily damaged by Allied bombing in 1945. The communist authorities of East Berlin demolished the building in the 1950s, and today's Berlin government is pursuing an ambitious project to rebuild the palace according to a design by Italian architect Franco Stella, which will recreate the facade of the building but with a modern interior at a cost of approximately EUR 590 million. The Humboldt Forum, the foundation leading the project, has given the Schlossbauhuette sculptors the formidable task of recreating the hundreds of architectural elements that decorated the facade, and though some original pieces were saved, more often the sculptors have only old black and white photos as reference. (Photo by Sean Gallup/Getty Images)

The War in Abkhazia from 1992 to 1993 was fought between Georgian government forces for the most part, and Abkhaz separatist forces, Russian armed forces and North Caucasian militants. Ethnic Georgians who lived in Abkhazia fought largely on the side of Georgian government forces. Ethnic Armenians and Russians within Abkhazia's population largely supported the Abkhazians, and many fought on their side. The separatists received support from thousands of North Caucasus and Cossack militants and from the Russian Federation forces stationed in and near Abkhazia. Here: Abkhazia. Sukhumi, 1993. A house-to-house combat. (Photo by Andrei Solovyov/ITAR-TASS)

People perform during celebrations to commemorate the 70th anniversary of the establishment of the Vietnam Public Security police force at the National Convention Center in Hanoi August 18, 2015. The Vietnam Police force was founded on August 19, 1945, the day of the anti-colonial people's uprising known as the August Revolution. (Photo by Reuters/Kham)

Commander of the Joint Forces of the Armed Forces of Ukraine Serhiy Nayev holds puppies as he visits at positions near the border with Belarus, amid Russia's attack on Ukraine, in Zhytomyr region, Ukraine on September 20, 2023. (Photo by Gleb Garanich/Reuters)