“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)

Indya Moore attends the 2019 Time 100 Gala at Frederick P. Rose Hall, Jazz at Lincoln Center on April 23, 2019 in New York City. (Photo by Andrew Kelly/Reuters)

Japan's Naomi Osaka returns the ball during her match against Slovakia's Dominika Cibulkova during the Madrid Open tennis tournament, Sunday, May 5, 2019, in Madrid, Spain. (Photo by Andrea Comas/AP Photo)

England goalkeeper Mary Earps saves a penalty from Jennifer Hermoso of Spain during the FIFA Women's World Cup Australia & New Zealand 2023 Final match between Spain and England at Stadium Australia on August 20, 2023 in Sydney, Australia. (Photo by Charlotte Wilson/Offside/Offside via Getty Images)

Venezuelan Hildemaro Ortiz relaxes inside of an abandoned bus in the border city of Pacaraima, Brazil on April 13, 2019. Ten destitute Venezuelan migrants who fled their country's crisis did not get far when they crossed into Brazil: they have been living for three months on an abandoned bus just across the border. (Photo by Pilar Olivares/Reuters)

Anti-frost candles burn in apricot plantations to protect flowering buds and blossoms from frost in the midst of the Swiss Alps, in Saxon, Canton of Valais, Switzerland, 05 April 2019. With an unusually low temperature forecast for the season, fruit growers try to protect their buds from frost damage with two different means, icy water or large candles. (Photo by Valentin Flauraud/EPA/EFE)

Green building also known as green construction or sustainable building is the practice of creating structures and using processes that are environmentally responsible and resource-efficient.