A space probe was either a robotic space exploration device launched by spacecraft or a spacecraft with robotic attachments. Some space probes had autonomic capacities (i.e. they controlled their own actions), while others depended entirely on being controlled by the sender.
Humans began sending space probes out from Earth as early as the 1950s (TV: Delta and the Bannermen) and would continue to do so into the 21st century. (TV: The Christmas Invasion)
None of the probes that ventured too close to the Ever-and-Ever Prolixity returned. (AUDIO: The Lamentation Cipher)