ˈspace probe noun [countable]
a spacecraft without people in it, that is sent into space to collect information about the conditions there and send the information back to Earth

[TahlilGaran] Dictionary of Contemporary English ▲

space probe
n., Space English An unmanned spacecraft other than an Earth satellite fitted with instruments which gather and transmit information about other planets in the solar system (e.g., Venus, Mars, and Jupiter) on what are called fly-by missions, i.e., without the craft landing on any of these bodies.
Both the U.S.A. and Russia have sent up many a space probe in the past decade.

[TahlilGaran] English Idioms Dictionary ▲