A long steel-grated walkway used by astronauts just before a launch to go from the service-tower lift to the sterile white room next to the spacecraft's open hatch. The catwalk swings away from the shuttle seven minutes before launch.
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。