space probe
A spacecraft designed for exploration, often unmanned. Compare with 宇宙探査機, which is a more general term for space probes.
See also: 宇宙探査機
A space probe is investigating the surface of Mars.
宇宙探査機 is a broader term for space probes, while 宇宙探査船 specifically suggests a larger vessel or ship-like probe.
Compound of 宇宙 (space), 探査 (exploration), and 船 (ship).