The first step in the Deep Sentinel program, one of the most ambitious ocean-engineering projects in decades, will be completed this year. This initial step, called Vanguard, will shelter three aquanaut-scientists at depths of 100 meters. Eventually, the project will create a modular underwater habitat system that will let scientists live underwater for weeks at a time.
Sure, but space habitats are far far more useful than underwater ones
There is definitively no shortage of challenges in orbit