Examination of Cloud Seeding on Board of the International Space Station: Experimental and Modeling Approach

This work summarizes the first results from a cloud seeding in microgravity experiment built by the Saudi Space Agency (SSA) and conducted on the International Space Station (ISS). The microgravity conditions provided in the ISS enable examining the interaction between the seeding agent, silver iodide, and the water droplets. Silver iodide particles dynamics of radius of 0.6, 0.3, 0.2, and 0.1 μm are examined in the ground and at the ISS at room temperature and atmospheric pressure in four 5cm³ chambers. Meanwhile, computer simulations are employed to examine the dynamics of seeding agent falling under the effect of gravity. It is found that microgravity conditions along with reducing seeding particles’ size enhance the interaction between seeding particles and the water droplets by increasing the period at which particles staying in the air before dropping down to the floor of the experiment. Humidity level in the experiment is observed to decrease onboard of the ISS because of the interaction between seeding agent and the water droplets.