the short flights of the shuttle and earlier spacecraft, which enabled them to carry sufficient enough power in fuel cells and batteries
由于the shuttle and earlier spacecraft 是修饰the short flights，相当于是the shuttle's and earlier spacecraft's short flight的结构，所以the shuttle and earlier spacecraft不是代词them 好的指代对象，因此说them语法上指代了short flight，但是逻辑上是要指代the shuttle and earlier spacecraft。
但是，manhattan 4th中我记得说过就是因为N1'S N2这样名词修饰名词的结构使得原本应该指代N1的代词没有办法指代，所以才要换成 N2 OF N1的结构，使得后面代词能够指代N1，这么说来OF 后面的名词是可以被指代的，这样与我上面的理解就有矛盾了... 请牛牛们帮忙解答呀！万分感谢！