A solar sail lets a spacecraft ride on sunlight the way sailboats ride on the wind. Dr. Jeannette Heiligers (TU Delft) uses the propulsion capabilities of solar sailing for a sustainable ‘space duster’: a device that moves to a piece of debris and deorbits it, so that space gets cleaner. Solar sails can also be used as shields. If an immense solar shield were to be unfolded in space, this could reduce the Earth's temperature and limit the effects of climate change. Is this a wise thing to do? In cooperation with Space Society Twente, KIVI Students Twente and Arago.