Recovering space probes presents several significant challenges, which vary depending on their mission and destination. Most space probes are not designed to be retrieved; they are built to operate autonomously for their entire mission duration, often collecting and transmitting data back to Earth until they no longer function. These probes often travel vast distances, sometimes into interplanetary or even interstellar space, making physical retrieval highly impractical with current technology.
For probes that remain in orbit around Earth, such as satellites, recovery is theoretically more feasible but still complex and costly. It would require a mission with capture capabilities, such as a spacecraft with a robotic arm or a specialized vehicle to safely deorbit and return the probe to Earth. However, this is seldom attempted due to the significant expense and potential risk involved compared to launching new probes with updated technologies.
If a space probe lands back on Earth, as was the case with some lunar and Martian sample return missions, recovery can be accomplished, albeit with precise planning and execution. Such missions are explicitly designed to bring back material for analysis and employ mechanism like reentry capsules capable of withstanding the harsh conditions of descent through Earth’s atmosphere.
In summary, while it is theoretically possible to retrieve some space probes, it is not typically done due to the logistical and financial hurdles compared to developing and launching new missions.