Buried beneath 4,000 feet of Antarctic ice lies Lake Mercer, a subglacial body of water that formed thousands of years ago and has been long separated from the rest of the world. A project to explore this lake—and its mysterious contents—is finally set to begin later this month.

Called Subglacial Antarctic Lakes Scientific Access, or SALSA for short, the project aims to uncover new knowledge about Antarctica’s subglacial lakes, of which over 400 are known to exist. Over the next two months, SALSA scientists will explore one of the largest subglacial lakes in West Antarctica, a body of water known as Lake Mercer. The team will bore through some 4,000 feet (1,200 meters) of ice using a 60-centimeter-wide drill capped with hot water. In addition to extracting water and mud samples, the researchers will deploy a remotely operated vehicle—a scientific first for a subglacial lake.