A fleet of 8 toaster-oven sized satellites are heading to orbit with the task of seeing through rain. NASA’s Cyclone Global Navigation Satellite System will measure wind speeds in the tropics to better understand cyclones and hurricanes. And it does this in a pretty interesting way: using left-over GPS signals beamed down to earth.

Derek Posselt is a scientist at NASA’s Jet Propulsion Lab in California and he joins the program to talk about the mission and the technology that helps this fleet work.