Saturday, October 24, 1998 Published at 17:39 GMT 18:39 UK
Probing deep space
To boldy go: DS1 breaking new frontiers (NASA/JPL/Caltech)
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.
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.
"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.
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.