In 1980, the American Helicopter Society offered $250,000 to anyone who could build a human-powered helicopter, hover for 60 seconds, and reach 3 meters of altitude. For 33 years, nobody could do it.

Then a group of University of Toronto students and alumni decided to try.

Their aircraft, Atlas, looked nothing like a helicopter. Four rotors spanning nearly 60 meters in total, built from carbon fiber and mylar film so light the whole machine weighed less than 55 kilograms. The pilot pedaled a bicycle drivetrain at the center, generating just enough power to lift both the aircraft and themselves off the ground.

In June 2013, pilot Todd Reichert held Atlas aloft for 64 seconds, reaching 3.3 meters. The prize was claimed.

What makes the achievement interesting beyond the spectacle is what it says about the gap between "theoretically possible" and "actually done." The physics were understood for decades. The materials existed. What it took was a team willing to spend years on a problem most people had quietly given up on.