High vacuum is a very low-pressure environment, usually created by pumping air and other gases out of a chamber. In sensitive equipment, this reduces collisions, contamination, and electrical interference, allowing beams, sensors, or moving parts to behave predictably. In systems such as electron microscopes, the vacuum is not optional: it is part of the operating environment that makes the instrument work at all.
For cyber security, high vacuum matters because the pumps, gauges, valves, and controllers that maintain it are often software-driven. If an attacker or faulty configuration changes setpoints, disables monitoring, or spoofs sensor readings, the hardware can become unstable or unsafe. Defenders therefore treat vacuum control as a cyber-physical security target: they log controller activity, verify sensor integrity, and design fail-safes so the chamber can shut down cleanly if pressure drifts outside safe limits.