An article in the Chicago Tribune on the spacewalk to repair gap fillers sticking out between heat-resistant tiles on the underside of the shuttle Discovery quotes Michael Holden, an aerodynamics engineer in the Calspan UB Research Center (CUBRC), which was involved in NASA's return-to-flight preparations following the destruction of the shuttle Columbia. Holden says there's little real chance that the gap filler problem could result in loss of the shuttle and its crew, but NASA is being "ultra-careful." The article was picked up by about 20 outlets, including the Philadelphia Daily News, St. Paul Pioneer Press and Kansas City Star.