“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)

Belgium's Crown Princess Elisabeth, center, marches past the Royal tribune with cadets of the military school during the National Day parade in Brussels, Wednesday, July 21, 2021. Belgium celebrates its National Day on Wednesday in a scaled down version due to coronavirus, COVID-19 measures. (Photo by Olivier Matthys/AP Photo)

Route engineer Richard Winter stands in front of a pile of road salt at the Birchanger Depot on November 8, 2011 near Bishop's Stortford, England. (Photo by Peter Macdiarmid/Getty Images)

Fans of American football gathered at Tottenham Hotspur Stadium to watch the Jacksonville Jaguars win against the Buffalo Bills 25-20 in the NFL on October 08, 2023 in London, England. (Photo by Peter Tarry/The Times)

A Kevo smart lock is demonstrated during the 2015 International Consumer Electronics Show (CES) in Las Vegas, Nevada January 4, 2015. The lock, which opens with a smart phone App and a touch, is smart enough to know what side of the door you are on and won't accidentally unlock the door when you are inside. A new subscription service offers unlimited e-keys and other benefits, a representative said. (Photo by Steve Marcus/Reuters)

Toyota revealed its i-Road concept, a three-wheeled all-electric motorcycle of sorts that seats two. The unique design is only 33 inches wide, which would make it tops in buzzing in through and around traffic. An Active Lean system tilts the i-Road through corners like a motorbike, while the cabin (which seats two in a tandem layout) is fully enclosed. Maximum range is about 30 miles. (Photo by Luis Fernando Ramos/G1)

The new MacBook Pro is shown during the keynote address at the Apple 2012 World Wide Developers Conference (WWDC) at Moscone West on June 11, 2012 in San Francisco, California. This is Apple’s latest flagship laptop featuring an updated processor and a super high resolution screen that features 5.1 million pixels – 3 million more than a typical high-definition television.