With the successful launch today of the Tianhe core module of its space station, China begins to carry out the third phase of its manned space program. That series of missions was a 30-year program, culminating in the operation of an Earth-orbiting space station in 2020.
The first phase had the goal of demonstrating that manned space flight was safe. That was accomplished in 2003.The second phase, which lasted from then until now, demonstrated many of the technologies needed for long-duration spaceflight, such as extravehicular activity and refueling.
