Enlarge / Complex space systems like the International Space Station could be vulnerable to hackers. (credit: NASA) If space systems such as GPS were hacked and knocked offline, much of the world would instantly be returned to the communications and navigation technologies of the 1950s. Yet space cybersecurity is largely invisible to the public at a time of heightened geopolitical tensions. Cyberattacks on satellites have occurred since the 1980s, but the global wake-up alarm went off only a couple of years ago.