Before astronaut capsules can be rated has safe for humans, they must be drop tested. Boeing has an advanced new astronaut capsule known as the CST-100 Starliner, which NASA recently performed drop tests on to test its safety and function.
Of course, it's not the real Starliner, it's just a duplicate made to simulate the drop of the Starliner. Equipped with sensors to indicate the forces at work during the drop test, NASA can accurately determine whether or not the capsule is safe for human landings back on Earth.
The capsule was dropped into a 20-foot deep hydro impact basin at one of NASA's test facilities on February 9th, 2016.
In a real-world scenario, such a capsule would land on solid ground instead of water, but initial water drop tests are a good way to test and see if the capsule can hold up to initial dropping and potential emergency landings.