Here's what China wants from its next space station

The Tianhe-1 module that launched this week is the core of what is supposed to be a three-part space station. On the surface, it seems to pale in comparison to the 22-year-old ISS. The ISS is a football-field-size behemoth weighing about 420 metric tons, while the much smaller T-shaped Chinese Space Station (CSS) will be a mere 80 to 100 tons, closer to the size and mass of Russia's former Mir station. The Tianhe-1 module is just 22 tons and 16.6 meters long. And after 12 missions this year and next to put the whole thing together, the completed station will still be roughly half the length of the ISS.