With a new job lined up with a local contractor, Steve Cook, manager of NASAโ€™s Ares Project Office at Marshall Space Flight Center in Huntsville, Ala., announced his resignation Aug. 27, ending a 19-year career with the U.S. space agency. NASA headquarters spokesman Grey Huataluoma confirmed Cookโ€™s planned departure Aug. 28.

As director of the Ares Program Office since its inception in 2005, Cook oversees Marshallโ€™s development of the Ares 1 crew launch vehicle and the Ares 5 heavy-lift rocket central to NASAโ€™s five-year-old plan for sending astronauts to the Moon by 2020. 

Cookโ€™s resignation comes at an uncertain time for Ares and the Moon-bound Constellation program in general.

In May, the White House tasked a blue-ribbon panel with reviewing NASAโ€™s manned spaceflight plans and providing a range of options for the future. The panel, which briefed White House officials Aug. 14, found that Ares 1 and its Orion Crew Exploration Vehicle are not likely to debut before 2017 โ€” two years beyond NASAโ€™s targeted operational date.

Cook will assume his new post as director of space technologies at Huntsville-based government contractor Dynetics on Sept. 14, according to his Aug. 27 resignation announcement to the Ares team. Teresa Vanhooser will become acting Ares manager effective Aug. 31.