 Launched uncrewed aboard a Long March 2F/G rocket on 29 September 2011, it was the first operational component of the Tiangong program, which aims to place a larger, modular station into orbit by 2023.Tiangong-1 was initially projected to be deorbited in 2013, to be replaced over the following decade by the larger Tiangong-2 and Tiangong-3 modules, but it orbited until 2 April 2018.Tiangong-1 was visited by a series of Shenzhou spacecraft during its two-year operational lifetime.