A yam farm in northern Ghana, with wooden stakes used to support the yam plants as they grow. These “yam sticks” are often harvested from surrounding forest. Image by Attah Mohammed via ...

On a vast yam farm, [Jean-Patrice Keka] has single-handedly developed several rockets that have flirted with the elusive zero gravity environment. [Mr. Keka’s] ‘Mission Control’ is a ...