Thankfully, no astronaut has ever been irretrievably lost in space.
While there have been incidents where astronauts have become detached from their spacecraft during spacewalks, they were always recovered. Safety protocols and tethering systems are in place to prevent such situations from becoming fatal. These protocols are designed to quickly retrieve any astronaut who becomes separated. To date, no astronaut has drifted so far that recovery was impossible.
Although the possibility of an astronaut becoming lost forever in space is a terrifying scenario, the probability is incredibly low due to rigorous training, advanced technology, and established safety measures. The risk is managed and mitigated through multiple layers of redundancy.
