A near-flight prototype of a pulsed UV laser has been developed for the Mars Organic Molecule Analyzer (MOMA) of the ExoMars mission. The laser head is based on a Nd:YAG oscillator with subsequent frequency quadrupling and emits nanosecond pulses wi th an energy of > 300 μJ at a wavelength of 266 nm. The design is compact and lightweight. Te sts in relevant environmen t regarding temperature, vibration, and radiation have been performed.