We have begun building the ''Mercury'' laser system as the first in a series of new generation diode-pumped solid-state lasers for target physics research. Mercury will integrate three key technologies: diodes, crystals, and gas cooling, within a unique laser architecture that is scalable to kilojoule and megajoule energy levels for fusion energy applications. The primary near-term performance goals include 10% electrical efficiencies at 10 Hz and 100 J with a 2-10 ns pulse length at 1.047 {micro}m wavelength. Currently, this review concentrates on the critical development and production of Yb:S-FAP crystals. After solving many defect issues that can be present in the crystals, reproducibility is the final issue that needs to be resolved. We have enlisted the help of national experts and have strongly integrated two capable commercial crystal growth companies (Litton-Airton/Synoptics and Scientific Materials) into the effort, and have solicited the advice of Robert Morris (retired from Allied Signal), a recognized international expert in high temperature oxide growth.