 Complete the following phrase:  After her flight on STS-85, Davis was assigned to NASA Headquarters as the Director of the Human Exploration and Development of Space HEDS, Independent Assurance Office for the Office of Safety and Mission Assurance. In that position, Davis managed and directed independent assessments for the programs and projects assigned to the HEDS enterprise. In July 1999, she transferred to the Marshall Space Flight Center as Director of the Flight Projects Directorate, which was responsible for the International Space Station ISS Payload Operations Center, ISS hardware and the Chandra X-Ray Observatory Program. After the 