Flights to Mars , for example, could have people going on conventional rockets while cargo is relegated to the slower, ion-drive rockets. But you would only use it as long as you've got plenty of time to travel. Russia also has six communications satellites that use ion propulsion for station keeping. But Deep Space 1 is the first spacecraft to use it as a primary means of propulsion. Instead of the fiery thrust produced by typical rockets, an ion engine emits only an eerie blue glow as electrically charged atoms of xenon are pushed out of the engine.
Xenon is the same gas found in photo flash bulbs and lighthouse search lamps.
In the engine, each xenon atom is stripped of an electron, leaving an electrically charged particle called an ion. Those ions are then jolted by electricity that is produced by the probe's solar panels and accelerated at high speeds as they shoot out from the engine. That produces thrust for the probe. But Deep Space 1 doesn t move that fast in the other direction because it is much heavier than the ions. I like to say it's acceleration with patience.