This experiment will determine the rate at which pore collapse occurs in (compact) Amoprhous Solid Water (ASW), determining the size and shape changes involved in the pore collapse, and generating an empirical rate equation which can subsequently be applied to understanding the temperature and temporal evolution of this metastable condensed-matter material, particularly in an astrophysical context. The experiment exploits the unique Q-range capabilities of NIMROD, capable of determining both the micro- and meso-scale structure of samples concurrently. The results will be of importance in understanding the properties of ASW, the most commonly encountered form of water in the universe, and how pore collapse impacts on the chemistry and physics that can be occurring during planet and star formation.