Constellation program
In November 2003, Zubrin was invited to speak to the U.S. Senate committee on the future of space exploration. Two months later the Bush administration announced the creation of the Constellation program, a human spaceflight initiative with the goal of sending humans to the Moon by 2020. While a Mars mission was not specifically detailed, a plan to reach Mars based on utilizing the Orion spacecraft was tentatively developed for implementation in the 2030s. In 2009 the Obama administration began a review of the Constellation program, and after budgetary concerns the program was cancelled in 2010.