Sandia Energy > Programs > Renewable Energy > Concentrating Solar Power > Staff > Mark J. Speir Mark J. Speir Operations & Test Engineer Mark Speir is a seasoned, hands-on field engineer with broad experience primarily in aerospace and concentrated solar energy. Mark earned an aeronautics undergraduate degree from Embry Riddle University and graduate degree from Albertus Magnus College. Mark has 25+ years in aerospace, which includes work on the Space Shuttle, Minuteman III, large turbine jet engines, and solid fueled rockets. In addition to extensive aerospace experience, Mark has made large contributions to the molten salt power tower development, where he primarily worked to design, build, and test prototype heliostats for the 110Mw Crescent Dunes concentrated solar power plant in Tonopah, NV, starting in 2008. More recently, Mark has worked as a systems engineer on the Enhanced Capability for Subcritical Experiments (ECSE) Advanced Systems and Detectors (ASD) Scorpius program, which aims to field an accelerator for radiographic imaging of subcritical elements. He accepted a recent opportunity to return to the National Solar Thermal Test Facility (NSTTF) and will support various research projects. Reach out to Mark with any capability questions for on-site testing at the NSTTF.