MERLIN (Methane Remote Sensing LIDAR Mission) is a joint DLR/CNES mission, which will measure column densities of methane in the atmosphere. The laser's optical bench, at the core of the instrument's transmitter, is developed by the Fraunhofer Institute for Laser Technology and features technologies which enable high-stability laser performance operation in space conditions. Those technologies were demonstrated for the first time in the frame of the FULAS project and were adapted for MERLIN. This paper will present evidence of the technology's capability to support long lifetime missions, of the achievement of high pointing, energy and spectral stabilities based on representative breadboard campaigns and of the technology maturity for space based on subassembly and component level.