The fuel can be made from a number of substances:

• High Energy Density
• Easy to machine, or mould
• Available (cheap too would be good!)
• Not too sooty, or melt too easily. We need to ensure the nozzle is not clogged during usage.
• Most have a single hole in the middle, although some designs have grooves for additional surface areas, other make use of several holes through the material.

(http://science.nasa.gov/science-news/science-at-nasa/2003/28jan_envirorocket/): Pros: Cheap, readily available, easy to form

Disadvanages: Melts easily so could be problematic to ignite. Can melt and be spewed out the nozzle unburnt:http://myweb.tiscali.co.uk/aspirespace/wax%20hybrids.htm

Pros: Can buy set yourself urethane rubber.

Cons: Could be difficult to handle, potentially toxic when burnt.

Cheap, easy to cast into desired shape.

May melt or clog nozzle

Should be stored in freezer bags to avoid absorbing moisture.

Non-toxic.

Sorbitol and dextrose are preferred.

Relevant information:

http://www.aeroconsystems.com/motors/sugar_motor/SugarPro_Proposal.pdf http://www.nakka-rocketry.net

: Pros: Available and easy to shape to the required size. Easy to light, as burns on its own

Cons: Could fall apart when burnt

==== High density polyethylene: ==== Pros: Easy to machine (likely to be best to buy a rod, and machine to size( Fairly cheap and available. Clean burning, and popular in the hybrid rocket community.

Increase the specific impulse and burn rate. Generally powdered metals such as iron or aluminium. Carbon black could be used.