Characterization tests were conducted on the inert solid propellant cast in the 1/8 scale models of the space shuttle. Static and dynamic tests were carried out to evaluate the interconvertibility of static and dynamic response properties according to linear viscoelasticity theory. These tests were carried out at several temperatures and the time (frequency)- temperature superposition principle used to extend the range of applicability of the data. Tests were also conducted to evaluate the effects of moisture (l.e., relative humidity) on propellant response and also the effects of static strain level. A discussion and analysis of the test program and test results are also included.