Abstract: Experiments are conducted to quantify the formation and clearing of iodine clogs in an iodine feed system. Deposits in the low-pressure portion of the system near the exit to vacuum appear to be relatively small in extent and incomplete in blocking the flow, and they are relatively easy to remove with the re-application of heating, disappearing in minutes. Clogs forming upstream, nearer to the higher-pressure propellant tank, appear to completely block the flow, are much larger in spatial ext…