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)無人駕駛的[usu ADJ n]

...a special unmanned spacecraft. ...一架特殊的無人駕駛的宇宙飛船。

2. ADJ If a place is unmanned, there is nobody working there. (地方)空無一人的

Unmanned post offices meant millions of letters went unsorted. 空無一人的郵侷意味著上百萬的信件無人処理。