unmanned spacecraft
Refers to a spacecraft without a human crew, used in contexts of space exploration, cargo resupply, or satellite deployment.
An unmanned spacecraft landed on Mars.
This unmanned spacecraft carries supplies to the International Space Station.
有人宇宙船 means 'manned spacecraft', contrasting with 無人宇宙船.
宇宙探査機 is a broader term for space probes, which may include unmanned spacecraft but also landers and rovers.
Compound of 無人 (むじん, 'unmanned') + 宇宙船 (うちゅうせん, 'spacecraft').