对航天飞机的雷达追踪，如最后精确的陆基导航，还没有开始。

Radar tracking of the shuttle, like the final accurate ground-based navigation, had not yet begun.

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中期1942年，他投入了大量的普拉特，立百基飞机公司，建筑的美陆军第一直升机的XR - 1(图2)。

By mid-1942 he had invested substantially in the Platt-LePage Aircraft Corporation, builders of the US Army's first helicopter, the XR-1 (Fig. 2).

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