Symbolism, Imagery, Allegory
There's No "I" In "Team"
The team-up between NASA and the China National Space Administration (CNSA) is a pretty awesome moment. It's the space program equivalent of having Batman and Superman on the same team. Still, it's surprising how much the CNSA is willing to sacrifice—namely, the Taiyang Shen probe—for the sake of Mark Watney.
This is such a big deal because Taiyang Shen is the most technologically advanced probe they've ever made: "countless [...] researchers, scientists, and engineers [...] poured their souls into construction" (19.183). And that's not even getting into the financial side of things. If they give up the booster to help NASA reach Mars, they'll lose their one and only shot at launching the Taiyang Shen mission.
No matter which way you look at it, the CNSA is giving up a lot and getting very little. They'll get a Chinese astronaut on Mars, sure, but that's a mere consolation prize. No, they end up helping NASA for one reason: to save Mark Watney's life. It certainly helps that the scientists at the organization feel a kinship with those at NASA, bolstered by the fact that the "love of science is universal across all cultures" (18.58).
In this way, the donation of Taiyang Shen is the epitome of Mark's assertion that "every human being has a basic instinct to help each other" (26.424). Nationality doesn't matter. Religion doesn't matter. Political affiliation doesn't matter. All that matters is getting one nerdy botanist back home, safe and sound. And if that doesn't make you say "Aww," well, your heart is probably as cold as the surface of Mars.