The doors began sliding open, accompanied by flashing lights and the sound of alarms as the air inside the small chamber vented into the vacuum of space around them. It seemed that the security system was not connected to the airlock controls, probably for this very reason.

Which meant they either needed to find some other way in, or get inside, re-pressurize the chamber and sweet-talk their way through the inner doors before some eager-to-hit-something sentients showed up to find out who'd opened the doors without permission.