The present disclosure relates to a system in space for reinforcing photosynthesis on earth, comprising a satellite with at least one first optical assembly intended for collecting sunlight, the position of which is stationary; a second optical assembly, smaller in size and with less inertia than the first optical element, intended for retransmitting the collected light with higher density of the retransmitted flux density than the collected flux density, and with an adjustable orientation; a remotely controllable means capable of adjusting the orientation of the second optical assembly; and a light-transmitting means which transmits the collected light from the first optical assembly to the second optical assembly. The second optical assembly retransmits light only in specified frequency hands around 450 nm and 660 nm.