‘The Gehenna Drop’ is a free adventure for Everywhen’s ‘Space Pulp’ supplement. From the blurb from DriveThru:

“This adventure mixes horror and military-themed sci-fi; a blend of Doom, Event Horizon, and Warhammer 40K elements.

A combat drop by space marines onto the volcanic moon Muspell-9 goes south, fast, when PCs discover demonic entities have taken over a secret research station. Can they survive long enough to figure out what the hell is going on?”

Link: https://www.drivethrurpg.com/en/product/519798/sp2-the-gehenna-drop