The upper edge of a spacecraft's re-entry corridor. If the vehicle enters above this level, the low atmospheric density will not slow it down enough, and the spacecraft will skip up into space again.
科学参考收录了60776条科技类词条,基本涵盖了常见科技类参考文献及英语词汇的翻译,是科学学习和研究的有利工具。