Michael Rossmann is a veteran virus crystallographer, with a standard X-ray tube right down the hall from his lab at Purdue University. But when he needs to perform ab initio structure determination - which requires tunable X-rays many orders of magnitude brighter than his standard Purdue X-ray tube - he and his colleagues pile into the car with some toiletries, a change of clothes, and a dewar full of frozen protein crystals for the 120-mile drive across the Indiana state line to the Advanced Photon Source (APS) at Argonne National Laboratories, just outside Chicago. APS is one of the country's premier synchrotron facilities.