Mobile Guardian Transporter (IMAGE) DOE/Sandia National Laboratories Caption Using the Sandia National Laboratories' sled track, rockets propelled the semitractor-trailer at highway speeds into a prototype of an over-the-road Mobile Guardian Transporter conceptualized and built from scratch. Credit Photo courtesy of Sandia National Laboratories Usage Restrictions None 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.