Experiments on pure and inhomogeneous materials (meteorite samples) have been performed at the Sandiad National Laboratory (SNL) using a hohlraum source of soft X-rays. It is of interest to deduce the scaling of the ablation pressure with the radiation temperature in this class of experiment. This paper uses similarity relations deduced from a radiation diffusion model together with several theoretical expressions for the Rosseland mean free path of the target material. The resulting scaling laws are compared. The momentum coupling coefficient scaling with input radiation temperature is also given. As an example of the methodology, scaling results are given for the types of meteorites used in these recent experiments as well as for a comet model based on opacities obtained from the LANL TOPS code. This work is part of an on-going program to model the dymanic properties and interactions of Near Earth Object (NEO) materials in the context of NEO hazard mitigation.