The Constellation Program was NASA's planned future human spaceflight program between 2005 and 2009, which aimed to develop a new crewed spacecraft (Orion) and a pair of launchers (Ares I and Ares V) to continue servicing the International Space Station and return to the Moon.
As of 2009, a single uncrewed suborbital launch test (Ares I-X) had been flown, with crewed missions anticipated to begin between 2014 (when an uncrewed mission was indeed launched) and 2017-2019 (according to the independent Augustine Commission). On February 1, 2010, President Obama announced that he intended to cancel the program with the U.S. 2011 fiscal year budget. A revised proposal in April confirmed that the Orion spacecraft would be retained for future missions beyond low Earth orbit, with the Ares launchers redeveloped into the Space Launch System. However, the Constellation Program itself was cancelled, with low Earth orbit operations transferred to the Commercial Crew Development program, which itself would not begin crewed launches until Crew Dragon Demo-2 in 2020.