p /> But the company has yet to get its spacecraft off the ground and NASA dropped a multimillion dollar space transportation agreement with Rocketplane Global's sister company, Rocketplane Kistler, in October. "I was fortunate during my tenure at Rocketplane to work with an incredibly talented group of professionals," Herrington said in a statement issued by the Chickasaw Nation. "My decision to leave was a difficult one." Herrington said in the release that he plans to continue working in the commercial space industry, because he believes "commercial space is the next great adventure in aerospace." He said he will continue working with the Chickasaw Nation, for which he has appeared in television commercials, and to serve as an adviser to the national Institute for Space, Science and Security Centers at the University of Colorado at Colorado Springs.