BBC Science Correspondent Sue Nelson reports on a successful launch

Deep Space One is powered by a solar-powered ion engine previously only featured in science fiction such as Star Trek and Star Wars.

If the ion propulsion engine is successful, it could revolutionise space travel as future spacecraft will be lighter, cheaper and faster.

Ghostly blue trail (NASA/JPL/Caltech)

Instead of using standard chemicals, the Deep Space One will use xenon gas. By bombarding the gas with electrons, its atoms are given an electrical charge.

These ions are then accelerated by high voltage grids and expelled into space as an ion beam, leaving behind a ghostly blue trail.

Although the thrust from the engine is less pressure than the weight of a single sheet of paper in the hand, each day it will add between 15 mph to 20 mph to the probe's speed.

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In 300 days it will have accelerated the Deep Space One by 60,000 mph.

"I like to call it 'acceleration with patience,'" says Marc Rayman, the mission's chief engineer.

The ion propulsion system is powered by electricity from solar panels and a supply of xenon gas.

Nasa says it is 10 times more efficient than conventional rockets.

Ion drive: "acceleration with patience" (NASA/JPL/Caltech)

The drive can only be used in the vacuum of space so a small Delta rocket launched Deep Space One on its one to three year mission.

The spacecraft's first destination is an asteroid, flying within six miles of the surface. If the mission is extended, it will then take the first close-up images of a comet.

This means quicker, more direct routes to other planets and could cut years from a 10-year trip to Pluto.

Nasa has been developing ion propulsion for more than 30 years but this is the first time it will be used as the main source of propulsion.

Deep Space One will try out a dozen new technologies in total, including improved solar panels and better data transmitters.