From publisher blurb:
Out of Time
A team of burnt-out miners and scientists crosses a desolate asteroid in search of Sap, the home planet’s dwindling energy source. Forced into the role of last-minute saviors, they will come face to face with an alien intelligence, confront the legacy of the past, and grapple with how far they are willing to go to save the future.
Penumbra is a gritty science fiction scenario playable in one or two sessions. It is suitable for as few as one player or as many as six, and six pre-generated characters are provided. Presented as a hexcrawl, it comes complete with random encounters and keyed locations to explore. The asteroid will soon be out of range and the PCs have only 72 hours of oxygen left, so there’s no time to waste!