We propose to study the influence of deposition rates and annealing effects on microporous amorphous solid water samples (ASW) using NIMROD. The data will allow us to monitor the kinetics of the collapse of the micropore network with time and temperature and understand at the same time the mesoscale structure quantitatively in terms of pore size distribution, total pore surface area, etc. The unique advantage of NIMROD allowing for the first time such an analysis is the rapid collection time, which prevents contamination of the bulk samples with background gas, paired with an accessible Q-range covering both micro- and mesostructure aspects. The results will be of importance in understanding the properties of ASW, the most commonly encountered form of water in the universe, and the pore collapse impacts on the chemistry and physics that can be occurring during planet and star formation.