Can you retrieve a discarded item in No Mans Sky?

A possible solution could be to reload from a previous save! This depends heavily of course on the last time you saved the game though, although saves do occur frequently.

As of right now, there is no way to recover discarded items. Once it's gone, it's gone. Consider it a lesson in double checking and close reading.

While I cannot find a solid online source for this, from my own experience with the game, there is no way.