Zinc/sulphur propellant have been the most popular rocket propellant among rocket amateurs in many years. If you want higher specific impulse and at the same time a reasonable cheap propellant potassiumnitrate is the next logical step.

Many rocket amateurs have turned to potassiumnitrate at some point, but unfortunately not successfully. Many have tried to use sugar and later sorbitol, but only relatively small motors (100-200 g propellant) have been successfully. Basically you get an uncontrolled burning area of the propellant due to cracks initiated during cooling and solidifying.

DARK have abandoned the use of sugar and sorbitol. We are now searching for alternatives to avoid the above mentioned problems. The pictures below show some of our activities in this field.

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DARK members Niels Andreassen and Dennis Mikkelsen, preparing the characterisation motor for test.

The testbench team: Henrik Nissen, Søren Kilsgaard and Per Lundberg.

Checking signal from load cell.

Characterisation motor ready to be placed on load cell.

Hmmm... could this be the red button???. Data collection and fire control.

Static test of potassiumnitrate motor.

Well... still looking good. Aluminium motor casing still intact after test.

Is it still hot??? - I don't feel anything.

I bet this one is hot though.... - Possibly, but the little rocks are still where we put them...