Special Order 939 was a classified order issued by the Weyland-Yutani Corporation to the APOLLO mainframe aboard Sevastopol Station in 2137. The order tasked APOLLO with the protection of a sample specimen of the species Xenomorph XX121, maintaining the station's quarantine and disallowing communications, deeming all other considerations secondary. When an Alien was jettisoned from the station in the Gemini Exoplanet Solutions module, APOLLO responded by ordering its fleet of Working Joes to hunt down and kill the station's remaining human inhabitants.