Where do you put a space station out to pasture?
Retiring vehicles isn’t easy. Ships are beached so that they can be stripped and salvaged. Airplanes are parked in “boneyards” out in the desert. But if the vehicle you’re retiring from service weighs up to 143 tons and is moving through the sky at 25,000 miles per hour, you’re basically forced to look for some place in the ocean where you can avoid pulverizing some terrestrial life. In fact, you’re going to be looking at one place in the ocean: Point Nemo.
Point Nemo is a very special location in the southern Pacific ocean that is the farthest you can get from land anywhere on Earth. The closest shore is 1678 miles away, in Antarctica. It’s also rarely used as a shipping route, which makes it the perfect place to aim and “park” space debris as it falls out of orbit. Once an inactive satellite or resupply ship hits the water, it still has another two-and-a-half miles to sink before hitting bottom. At that point, it will sit in dark, 2° water, and pretty much be as ‘out of the way’ as anything could be.
Its hard to steer a shredded spacecraft
However, this doesn’t mean that dropping spacecraft on this location is a neat and tidy process. As objects hit the atmosphere at sub-orbital speeds, they start to burn and break up. While missions are designed to target Point Nemo with the last of their fuel and guidance systems, uncontrollable damage and fragmentation of the 161 retired spacecraft in question has grown the actual landing zone to around 24,855 square miles. The largest craft, the Mir space station, had a footprint of around 18,641 square miles, even though only 17% of the 143 ton structure survived reentry all the way to the ocean.
My kindergartner asked: Is this anywhere near us? No, this is purposely not near anybody. Well, what about fish? Are these things falling on fish? While there is life in deep portions of the ocean, it’s limited to things like squid, whales hunting for squid, sponges, etc. While animals at the surface are at risk of being killed by debris, nothing should be landing on richer, more densely populated locations like a coral reef.
Source: This Watery Graveyard Is the Resting Place for 161 Sunken Spaceships by Kiona Smith-Strickland, Gizmodo