Pilots Bertrand Piccard and Andre Borschberg have completed the world’s first round-the-world solar powered flight. Their highly-publicized single-seater aircraft, the Solar Impulse 2, arrived in Ahu Dhabi on July 26 after flying nearly 40,000 km in a journey that started in March 2015, took a hiatus in July 2015, and picked back up in April 2016.

Solar Impulse has 17,248 solar cells that supply the plane with renewable energy. The cells recharge four lithium polymer batteries totaling 633 kilograms (1,395 pounds) each. According to aircraft database website Aiframer, a big part of the plane’s structure comes from materials from all over the composites industry.

One of the major contributors to the plane’s development was Covestro, which was responsible for the design and construction of the Si2 cockpit. The cockpit is made with advanced polyurethane and polycarbonate systems, significantly reducing the weight of the plane while and providing pilot protection. Covestro also worked on the door hinges, which were reinforced a custom polyurethane resin with carbon fiber and molded by resin transfer molding (RTM).

Another major contributor to the plane was Solvay, which made the wing spar structure of the aircraft with a novel out-of-autoclave technique. That allowed the company to create high quality, large composite molds and parts at low cure temperatures for the aircraft. Solvay also supplied composite rear stabilizer parts for the plane.

The airframe’s main and rear wing spars, fuselage and empennage were constructed from thin-ply epoxy prepregs produced by North Thin Ply Technology.

Another player in the development of the Solar Impulse is Dassault Systèmes, whose engineers designed the plane’s wing with carbon fiber composites. The wing had to be as light as possible while providing the lift needed at a cruising speed of around 90 kph. Overall, the plane weighs just 2,300 kilograms (5,070 pounds) – the largest aircraft ever built with such a low weight.

To learn more about Solar Impulse, check out “Flight of Fancy” from the November/December 2012 issue of Composites Manufacturing.