Overview of the German gel propulsion technology program

Gel propellants offer the possibility to build throttleable propulsion systems with easy handling and storage characteristics. This publication gives an overview of the conducted basic research activities and the technology development work within the German Gel Propulsion Technology Program, which was started in 2001. It covers various aspects of gel production, rheological properties, flow behavior, spray characteristics and combustion behavior, their application in rocket combustors and at least the successful free flights of two demonstrator missiles, each with a gel rocket engine on December 2nd, 2009. To sum up, one can say that up to now the understanding of basic processes as well as the knowledge about combustor and engine technology on gel propulsion could significantly be improved. The progress shows that the technology is ready for first applications, but nevertheless, there are still open gaps to close.