On the 27th of September 2007 the space probe Dawn,as shown on the right, was launched from Cape Canaveral. Dawn's 4.8-billion-kilometer journey includes exploration of asteroid Vesta in 2011 and the dwarf planet Ceres in 2015.

The spacecraft's engines use a unique, hyper-efficient system called ion propulsion, which uses electricity to ionize xenon to generate thrust. The three, 30-centimeter-wide ion thrusters provide less power than conventional engines but can maintain thrust for months at a time.

These engines use 1% of the mass of fuel that ordinary chemical engines use to produce the same power.

Explain how an ion-propulsion engine works. You may use a Power Point presentation, animations or any other visual media.

In your presentation answer the following questions
What is an ion?
Can such an engine lift a space ship from Earth's surface? Explain why.
What is the fuel used?
How does this fuel produce thrust?
Why are such large solar collectors necessary?
What is the the thrust produced by the engines?

You may find the URL below useful.

http://www.msnbc.msn.com/id/14622730/