After seven years of tinkering, they arrived at a machine with a deceptively simple design: Solar Impulse with its sleek, clean lines, white-gloss finish and rakishly angled 208-foot wings (bent to increase the plane's stability) resembles what you might get had Steve Jobs reimagined a child's balsa-wood glider in giant form.
Using balsa wood and other materials that would have been available in antiquity, Mr Heyerdahl built the Kon-Tiki, named after a mythical South American king said to have been fleeing for his life, and launched her from Peru.