Nasa's mission to the edge of the solar system, and beyond

Buzz Lightyear wanted to go to infinity and beyond: now Nasa wants to venture almost as far with a survey of the edge of the solar system.

The mission will involve launching a space laboratory and could answer some basic questions about the nature of interstellar space as well as laying the groundwork for the first journey of exploration beyond our solar system to the stars and their planets.

Nasa has given the go-ahead for the Interstellar Boundary Explorer - or Ibex - to be built ready for its launch in 2008 from a Pegasus rocket, which will be dropped from the underbelly of a high-altitude aircraft.

Ibex is expected to cost about US$141 million ($198 million).