The NSF Science and Technology Center for Dark Energy Biosphere Investigations (C-DEBI) invites proposals for 1-year research projects (in the anticipated range of $50,000-$80,000) and 1-2 year graduate student and postdoctoral fellowships that will significantly advance C-DEBI’s central research agenda: to investigate the subseafloor biosphere deep in marine sediment and oceanic crust, and to conduct multi-disciplinary studies to develop an integrated understanding of subseafloor microbial life at the molecular, cellular, and ecosystem scales. C-DEBI’s research agenda balances exploration-based discovery, hypothesis testing, data integration and synthesis, and systems-based modeling. C-DEBI research support is provided to “expeditions of opportunity”, and we’ve created a webpage listing potential options for participation. We welcome you to provide information about other expeditions of opportunity to share with the C-DEBI community! Help us further our mission to explore life beneath the seafloor and make transformative discoveries that advance science, benefit society, and inspire people of all ages and origins. C-DEBI welcomes proposals from applicants who would enhance diversity in C-DEBI and STEM fields. This request for proposals is open to all interested researchers at US institutions able to receive NSF funding as a subaward. The next deadline for these annual calls is December 1, 2017.