Previous results of the INSPIRE program have shown that the reactant injector plays a pivotal role in the operation of the RDC. The injector is responsible for the double tasks of rapidly injecting and mixing the reactants between successive wave passages while also resisting the backflow of reactants in the high pressure region behind the detonation wave. When poorly designed, the reactants are poorly mixed which reduces the combustion efficiency, or the injectors are too weak and the detonation wave degrades into counter-rotating waves. Previous injectors have overcome these challenges by simply allowing large pressure losses through the injector, however this comes at the cost of overall pressure gain. The current project will explore a range of injector configurations (e.g. axial jet-in-crossflow, co-annular pintle, inner- and outer-rearward step injector configurations) designed to minimize the total pressure loss while maximizing the mixing. The project will incorporate (i) scale model tests using acetone PLIF, (ii) reactive tests in the RDC to investigate performance and wave stabilization, (iii) throttling and operating envelope, (iv) comparison with numerical simulations performed with DC04 and DC07, (v) and Machine Learning techniques applied to the large data sets of high frequency experimental measurements to train ML algorithms for high-fidelity interpretation of low-resolution measurements