Part Transformer, part Star Wars stormtrooper and with hands that look like they can crush beer cans, at 1.8 metres tall and weighing 120 kilograms, NASA’s Valkyrie robot is an intimidating figure.

The robot has a unique design, consisting of a spherical body with a head that balances on top, staying more or less in place as the ball body rolls around. While no details of the design were ...