Most of the world welcomes it. The United States does not.

Crossing frontiers isn't entirely new for China. What media popularly call its "rise" is really a return — for most of human history, China's was the greatest civilization on Earth. China was also the world's most intrepid explorer. Fixing his eyes on the stars and braving the seas in the longest wooden ships ever built, the Chinese admiral Zheng He may have beaten Columbus to North America, and circumnavigated the globe before Magellan.

Then China went dark for almost 600 years. But today it's probing the limits of the known world once more, fixed on the very same stars — now with the hopes of visiting them.

China is building the world's largest radio telescope, which will outmeasure the American-run, 1,000-foot-wide Arecibo Observatory in Puerto Rico by more than 600 feet. It also has plans for the world's biggest solar telescope, nearly twice the size of the giant one that the US is currently constructing in Hawaii. This month China unveiled its Mars probe; its space lab will launch next year; and officials hope to place their first manned space station in orbit around 2022.