Mention the X Prize, and people might recall SpaceShipOne. In 2004, SpaceShipOne became the first privately sponsored craft to carry a person into space. Microsoft cofounder Paul Allen provided significant funding for the project, which was competing for and won the $10 million Ansari X Prize.

A slew of other challenges have since been established to encourage scientific innovation. This week, the X Prize Foundation announced an Automotive X Prize for the team that could "design, build, and sell super-efficient cars that people want to buy."

NASA also maintains a list on its Web site of challenges related to space exploration, including the Beam Power Challenge and the Tether Challenge. These annual challenges are part of the Elevator:2010 project. The project seeks the creation of a "space elevator" to transport material via a "physical stationary tether between the ground and an object in space, and a set of vehicles that can travel to space and back, moving on the tether using electric motors."

Links:
Automotive X Prize (X Prize Foundation)
Centennial Challenges (NASA)
Elevator:2010 (The Spaceward Foundation)
"X-Prize Sets Sights on 100 mpg Cars" (National Public Radio interview with Peter Diamandis, founder of the X Prize Foundation)

Photo: SpaceShipOne and White Knight by Beige Alert.