Landing Area and Rocket Plume Diagnostics

The importance of the Tactically Responsive Launch (TacRL) program lies in the fact that it increases the speed of launch operations allowing for the deployment of satellites and cargo to be made available to personnel at short notice in emergencies or during conflicts. This program aims to take advantage of the growing cadre of private launch providers (Masten Space, SpaceX, Blue Origin, etc.), many of which are funded by venture capital, to achieve these goals. One of the challenges that will be faced during this program is the development of technology that will allow rocket cargo to land on unfinished, irregular surfaces unlike those typically used by the private launch companies mentioned previously. In such cases, it is important to understand the mechanism of interaction between the plume and the various types of landing surfaces that it might encounter. To this end, the overall aim of the proposed effort will be to develop diagnostic tools that are capable of measuring velocity and/or identifying structures involved in plume-ground interactions. These tools will provide measurement data that can be used for validating and improving existing numerical models. Under the proposed Phase I effort, our team will initiate progress towards the overall goal by using a subscale reacting rocket model. The exhaust plume from this model will be visualized using appropriate high-speed imaging techniques to understand the temporal evolution of flow structures. In future phases, this test setup will be appropriately modified to include the effects of a planar surface of appropriate quality to recreate realistic landing scenarios that might be encountered by rocket-based cargo vehicles that support the TacRL program. These modifications will allow for the better characterization of the plume-ground interaction mechanism by studying the temporal evolution of flow structures in the plume as they interact with the ground plane and evolve thereafter. These metrics are crucial for assessing surface survivability as well as stand-off distances for personnel and critical ground equipment. The data collected during this program will prove to be an essential validation tool for the computational model that will be deployed by our team using our in-house, high resolution CFD solver.