天问二号不仅仅是一项科学探索。它也是中国雄心勃勃的天问三号任务的技术垫脚石。后者将于2028年发射，目标是从火星采集岩石样本并送回地球。美国为实现相同目标的类似计划正面临重大困难。

​China launched its first asteroid sample-return mission, Tianwen-2, in the early hours of Thursday, an endeavour to shed ...

XICHANG, May 29 (Xinhua) -- China launched its first asteroid sample-return mission, Tianwen-2, in the early hours of Thursday, an endeavour to shed light on the formation and evolution of asteroids ...