There are various ways in which to classify rocket propulsion systems, but one way of interest is by the physical method employed to produce thrust. In a majority of rocket systems, thrust is provided by thermodynamic expansion of a gas. The internal energy of the gas is hereby converted to kinetic energy of an exhaust flow. The thrust is then produced by the resulting gas pressure on the surfaces that are exposed to this gas. Alternatively, thrust can be generated by accelerating charged particles using electromagnetic fields. One can even generate thrust from gradients in the gravitational field.
Breakthroughs in advanced propulsion systems can significantly improve space mission performance well beyond what can be achieved with today's conventional systems. The main benefits would include improvements in overall mission delta-v manoeuvre capability and the enabling of entirely new missions or space transportation architectures. To further explore our solar system, faster trip times, substantial increase in payload mass delivery, or a large reduction in overall spacecraft mass/size is needed.
The activities within the Advanced Concept Team over the years have covered all of these aspects. By following the latest scientific advancements, we aim to provide a first look on future operational capabilities.