On a ship through a rough sea, if you are inside the bridge, you’ll have a tough time getting a clear vision. Fog, condensation, waves of saltwater — everything competes to kill the visibility. Engineers found that conventional windshield wipers weren’t that effective against constant exposure to saltwater and continuous operation.
So the solution? It’s those small round installations like this you see on the bridge windshields. Better known as clear view screens. They are driven by an enclosed motor that disperses water droplets as it spins. It also heats up the glass to vaporise droplets, thus allowing a small window of clear sight ahead. Similar to the ones in CNC machines and locomotives.
Pretty cool! Some view is better than no view, eh? :)
Collision cascading in space (Kessler syndrome) is what happens if the density of the space debris in the low earth orbit is high enough that one mishap could start a domino effect and cause more debris, eventually causing the rest of the satellites to collide with each other.
Ultimately, the additional debris from the collisions orbit the earth and render any future space expeditions impossible. Here’s a recent model of the current space debris status.