In thirty years from now the United States should have a manned spacecraft on Mars.
未来30年内,美国有可能会把载人航天器送上火星。
...the history of manned flight.
载人航天史
...manned exploration of the solar system.
对太阳系的载人航天探索
英汉双解词典包含141091条英汉词条,基本涵盖了全部常用单词的翻译及用法,是英语学习的有利工具。