"GM wants to power your car with nothing but fumes. Internal combustion has never been efficient. In fact, during the Victorian era, it was rejected in favor of steam power because of the rarity of petroleum. It's only these days, thanks to the abundance of oil from places like the Middle East that we can efficiently run on gasoline. Even with readily available sources for the combustible fuel, the act of using it to power our cars produces a lot of excess heat that doesn't get converted to mileage.

When Discovery's six astronauts take the final space shuttle ride to orbit in September, there'll be one more rider sitting in the back of the bus: Robonaut 2, the semi-humanoid robot created by NASA and GM.