The Evolution of High Altitude Solar Flight

The video discusses the evolution of experimental planes like the Helios prototype, designed for high altitude research. Helios, a solar-powered aircraft with a 75-meter wingspan, aimed to stay airborne for months. In 2001, it attempted a record altitude flight in Hawaii, monitored by a large ground team. The plane, controlled by elevators without flaps or rudder, faced challenges like wind vulnerability. Despite reaching over 29,000 meters, Helios crashed on a later flight.

How did the engineers control the altitude of the Helios without using elevators?

What was the record-breaking altitude achieved by Helios during its flight?