VOA慢速英语:阿波罗登月50年后 美国的首次登月计划

aerospace –adj. describing the industry of making vehicles that travel in the atmosphere and in space

customer –n. a person or organization that buys goods and services from businesses

certification –n. the process of gaining official approval to do something like carrying out a business or doing a task

mission –n. a flight or a spacecraft designed to carry out a task