It was widely known that Griffin hoped to keep his job under President Barack Obama so that Constellation and NASA's other programs could maintain their steady progress. In a phone call on the day after the election, Senator Bill Nelson (D, FL) requested of Lori Garver, who led the incoming Obama Administration's Transition Team, that the Administration allow Griffin to remain as NASA Administrator to provide programmatic and management continuity. However, his resignation (required of and offered by all agency heads due to an incoming President) was accepted. In part, this was because of disagreements between Griffin and Garver over the state of Project Constellation. Griffin gave a farewell address to NASA on 16 January 2009, in which he praised NASA for its recovery from the Space Shuttle "Columbia" disaster and urged employees to support the new administrator, whoever it may be. He left office the day President Obama was inaugurated.