For my PhD work, I investigate and build systems for the direct laser cooling of diatomic molecules. Ultracold studies of atomic systems have enabled a huge range of exciting work, building ultra-precise sensors, exploring new phases of matter, and (recently) offering insights into complex condensed matter systems. While atoms are not simple, and experiments with them are not easy, even diatomic molecules are immensely more complex. This makes experiments are harder, but the potential applications are richer. Over the course of my PhD I published numerous papers on specific aspects of molecule cooling, and demonstrated the first laser cooling of a hydride molecule. This work led to a million dollar grant from the W.M. Keck Foundation , to continue the project after I graduate. Additional information can be found on my groups website, and in the publications/pictures section.