The feasibility of adding heat to a supersonic airstream in the absence of flameholders was studied. Transient burning for periods of 3 to 10 milliseconds was achieved in a supersonic wind tunnel at nominal Mach numbers of 1.5, 2, 3, and 4. Steady burning was achieved for periods of 0.2 to 2 seconds at nominal Mach numbers of 1.5, 2, and 3. Burning and tunnel flow phenomena, including thermal choking, are described. Possible applications of the results of this study are suggested.