Actually, Tiangong-1 is only the first in a series of planned Chinese space stations. Tiangong-1 will be de-orbited soon and then replaced by Tiangong-2 in (probably) 2015. It will be followed by Tiangong-3, before the Chinese plan to move ahead with building a larger, modular space station in the mold of Mir and the ISS. The Chinese space station in Gravity is also refered to as "Tiangong", but it is no indication given which of the stations in the Tiangong series is meant. According to Wikipedia, the Soyuz capsule used by Ryan Stone is designated TMA-14M. The real-world Soyuz TMA-14M is currently scheduled for a launch in late 2014 and a landing in early 2015. We could perhaps surmise that Gravity is supposed to be set in the near-future year of 2015 and Chiese space station depicted in the movie is either Tiangong-2 or Tiangong-3.