From the introduction:
AIRLOCK is a space opera hack of SIGMATA: This Signal Kills Fascists, but is also a full standalone game. Readers familiar with SIGMATA’s rules will immediately grok how AIRLOCK works, though it does incorporate new rules, refinements, and scene types. AIRLOCK is designed for 1 game master and between 3 and 5 players. It requires pencils, paper, a printer, tokens (coins work fine), and piles of 6-sided and 10- sided dice if you want to play it analog, but it is optimized for play using online platforms like Roll20.net. Play sessions typically last between 2 and 4 hours.
AIRLOCK is a space opera game about a small crew of adventurers constantly getting into trouble, both on and off their spaceship. Our heroes, called voidnauts, are some of the most resilient, cunning, and capable specimens in deep space. Their ship, an advanced frigate armed to the teeth, is just as formidable. Whether the voidnauts are mercenaries, explorers, convicts, traders, scientists, diplomats, refugees, or something else entirely, they will inevitably get caught up in intergalactic struggles, chart unexplored systems, and most definitely regret responding to that distress signal.