A melted mixture of 70% potassium nitrate (KNO3) and 30% sorbitol (a salt maker) is one of the most used rocket fuel amongs amateur rockets. This fuel will among others be used in the international SStS (Sugar Shot to Space) where a one-stage amateur rocket must be able obtain an altitude of 100km.

As far as know, it was the Vlaamse Raket Organisatie which has first used this fuel combination . Today it is the most popular fuel combination.

Potassium nitrate (KNO3) - sorbitol thanks its popularity especially to the following facts:

• the fuel can be produced at a very low temperature (<110°C);
• the viscosity of the melted fuel is very late so that it can be poured very easy in forms, or even better: it can be melted directly in a mal;
• the components potassium nitrate and sorbitol can be obtained very easily and are rather cheap;
• the combustion speed of the fuel changes very little with rising pressure and is because of this very stable (a pressure increase due to a crack or bubble will cause few problems);