1) The Martian is set at some point in the future when manned space travel to Mars happens with technology we haven't built yet. So, we're projecting a bit our OWN technology.
2) China has landed a spacecraft on the moon, and currently has a spacecraft in a decaying orbit.
3) China puts their own satellites into space.
4) In The Martian, China helps out by launching a vessel filled with supplies to meet up with the US vessel as it slingshots around the earth. They (the Chinese) have the technology to do things very similar to that today.

Now, projecting their technology out to where it might be at whatever point in the future the movie is set, it's not unrealistic at all to think they could do what they could already get close to right now.