During his career at Jet Propulsion Laboratory Greg held many roles across multiple projects and missions. Most notably Greg served as a Surface Scientist for the Mars Science Laboratory (MSL) Mission, the Project Scientist for Lunar PUFFER Instruments development and the Cognizant Engineer for Mars analogs development for the Mars 2020 (Perseverance) Mission. In 2007 Greg received a NASA Space Act Award for conceiving RASP sampling technology, which was flown on the Phoenix Mars Mission. RASP sampling provided the historical-first water-ice sample ever taken on another planet. In 2017 Greg received a NASA Voyager Individual Award for his work in determining rock properties from MSL drill telemetry.  Currently Greg is an AST Technical Manager under NASA Armstrong’s Space Projects and Partnerships Branch for the Flight Opportunities Program where he works with technology developers and industry flight providers to increase technology spaceflight readiness through suborbital flights.