IMPOSED bluntness at the nose of a hypersonic vehicle is necessary to alleviate the oncoming heat load. However, increased wave drag is the immediate consequence of the forced bluntness. Hence, research in the field of hypersonics is always centered on the reduction of wave drag encountered by the space vehicles during their ascent phase. Most of the drag-reduction techniques are directed towards modifying the flowfield ahead of the stagnation point. Among the drag-reduction techniques, retractable spike is the simplest and is an easy-to-implement technique; hence, the forward-facing aerospike technique has attracted many researchers to consider various issues. Various configurations of aerospikes were assessed by Menezes et al. [1] to arrive at the best configuration for drag reduction on a 120 deg apex angle blunt cone, and a flat-disc-tipped aerospike of unity L=D (spike length-to-cone base-diameter ratio) with a disc diameter of 1 4 D was observed to be the most efficient drag-reducing agent. Therefore, a similar flat-disctipped aerospike configuration is considered in the present study to evaluate its effect on drag of a 120 deg apex-angle blunt cone under various total-enthalpy conditions. An accelerometer-based force balance was used to measure drag on the model in a conventional hypersonic shock tunnel, IITB-ST (Indian Institute of Technology Bombay—Shock Tunnel), at low-enthalpy conditions (1:1 0:02 and 1:5 0:03 MJ=kg), and high-enthalpy tests (5 0:44 MJ=kg) were conducted on the same model in a free-piston-driven hypersonic shock tunnel, HST3. Flowfield modifications brought about by the disc-tipped spike were expected to depend on the total enthalpy of the flow, as such a dependence was observed in the case of drag-reduction studies using a fluidic spike [2]. Details of the experimental methodology and the results are presented in the following sections. II. Test Facilities, Model, and Force Balance