Voidrunner is an occupation. The voidrunners are a group of explorers that jump into black holes which still have things well-preserved inside of them, and "spelunk" down there to find and/or collect said things and then return with whatever they have found in the void. They are highly-skilled and well-equipped entities, able to jump into a black hole, sustain themselves and perform wild feats necessary to enter such any anomalies as a black hole. 
- Solar Ash Interview: Lead Developer Discusses Accessibility, Transitioning to 3D, Speedrunning, & More.. Twinfinite. Banat, Omar. November 11, 2021.