In the history of space exploration, rockets have traditionally been disposable product. The first step towards making these space transport systems reusable was NASA's Space Shuttle programme. The shuttle, equipped with wings, did not need to reignite its engines to re-enter the atmosphere or to land; it returned to Earth with a horizontal glide. NASA ended the programme in 2011 after 135 missions. Currently, the Falcon 9 launch vehicle from Space X is the exception amongst other disposable stages – so far, only Space X regularly flies into space and lands the first stage.

Many research questions remain unanswered. For instance, the highly complex physics of flight have still not yet been conclusively investigated. Ideas and designs to return rockets through horizontal and vertical, reverse landing methods are being investigated, as both approaches offer unique advantages and disadvantages. What are these, and how do these technological methods function? Why is restarting a rocket engine more challenging than restarting an aircraft engine? How can artificial intelligence (AI) support research and development in this area? What capabilities should a modern test bed for new prototypes offer? And what is the best way to test various technological concepts?