Methane-Based Rocket Technology (2 of 2) (IMAGE) University of Texas at El Paso Caption In this 2011 photo, cSETR graduate students Juan Valenzuela (currently AST Propulsion Systems and Technologies Engineer at NASA Marshall Space Flight Center) and Humberto Hernandez (currently AST Propulsion Systems Engineer at NASA Johnson Space Center) are refilling propellant for the testing of a rocket engine. Credit Photo Courtesy: UTEP / cSETR Usage Restrictions Credit Required License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.