SpaceShipTwo, its inventively named commercial vehicle designed to take (well-moneyed) civilians into outerspace, has just completed its first rocket-powered test flight.

ENGADGET

The Air Force is also testing jet engines using biofuels and had the first successful biofuel-powered test flight just last week.

WHITEHOUSE: Energy Security and Independence

Speaking of sun-powered planes, the Solar Impulse just made its final test flight around the San Francisco Bay Area before embarking on a cross-country voyage next week.

ENGADGET: Inhabitat's Week in Green: flying electric car, 3D-printed livers and a two-story-tall bike