Answer: spaceprobe

AnswerCrossword Clue
SPACEPROBEGalileo, e.g.
SPACEPROBEMagellan, for one
SPACEPROBESolar system explorer
SPACEPROBERobotic solar system explorer
SPACEPROBECertain exploration
SPACEPROBEVoyager 2, e.g.
SPACEPROBEIt goes a long way
SPACEPROBEFar-off explorer