Ap-free composite propellants as reclament for AP/HTPB/AL

A comparative motor test was performed at Fraunhofer ICT with the aim to compare the actual state of the art in solid rocket propellant with a possible greener solution developed within the GRAIL project, which was further refined since the end of the project in January 2018. The trail was carried out as a ""proof of principle"" for the propellant. An aluminized solid rocket propellant based on GAP diol and a ternary mixture of ammonium dinitramide (ADN), ammonium nitrate (AN) and high energetic material has been evaluated and compared in a small-scale ballistic evaluation motor with the work horse for solid rockets of the last sixty years: aluminized ammonium perchlorate based propellant. On these days the environmental impact caused by the use of perchlorates is becoming intolerable due to their chlorine content. The aim of GRAIL was to determine if ammonium perchlorate (AP) can be replaced by using a mixture of new green high energy density oxidizer ammonium dinitramide (ADN) and the low cost oxidizer ammonium nitrate (AN). A motor test was already performed within the project but the results obtained were far from the expected due to the raise of unpredicted issues. ICT decided to continue the evaluation beyond the project and determine the potential of propellants with a dual oxidizer system composed of ADN and AN.