If Discovery isn't flying by then, it will have to get in line behind a Russian Soyuz rocket that's set to blast off March 26 with a fresh space station crew.

如果到时发现号还没有上天的话，发现号将不得不在预定于三月26日俄罗斯发射的联盟号火箭上天后才能升空。联盟号主要是运送新一轮空间站工作人员上天。