https://www.techradar.com/news/this-solar-powered-drone-can-stay-airborne-for-a-year > Main image: PHASA-35 will fly itself for months at a time. Credit: Prismatic/BAE Systems > The longest passenger flight is a whopping 19-hour service on Singapore Airlines between Singapore and Newark, but how about a non-stop flight lasting and entire year? British aerospace company Prismatic is now working on a solar-powered drone that can stay airborne for an entire year without any need for maintenance.