Experiments were carried out, at a strain rate of 1600 s−1, to characterise an HTPB/sugar propellant simulant within the temperature range of 50 °C to −100 °C. Optical techniques, namely high‐speed photography with digital speckle analysis for flow visualisation, and line‐laser occlusion to measure diametric expansion, were deployed. Agreement was found with the results of a previous study on a similar material: failure occurs by dewetting at temperatures above the glass transition temperature and brittle fracture occurs below. The peak strength of the material was recorded to be 80 MPa, measured at a temperature of −80 °C.