unmanned

1. ADJ Unmanned vehicles such as spacecraft do not have any people in them and operate automatically or are controlled from a distance. (交通工具)无人驾驶的[usu ADJ n]

...a special unmanned spacecraft. ...一架特殊的无人驾驶的宇宙飞船。

2. ADJ If a place is unmanned, there is nobody working there. (地方)空无一人的

Unmanned post offices meant millions of letters went unsorted. 空无一人的邮局意味着上百万的信件无人处理。