A unit on the space shuttle that was an auxiliary power source to gimbal (turn) the main engines. It was used during the shuttle's launch (activated by the pilot five minutes before blast-off) and re-entry.
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。