Where do rockets go to die? Well, some turn into space zombies. Some go down in flames. But some spacecraft return to Earth to take their place in a watery, ocean grave closer to home, in the (cue pipe organ super-chord) . . . Spacecraft Cemetery.
In the middle of the South Pacific Ocean, as far as is possible from the nearest human settlement – about 2,700km from the nearest inhabited island – lies an expanse of water known as the Spacecraft Cemetery.
The area is also sometimes called Point Nemo, after the submarine captain in Jules Verne’s novel 20,000 Leagues Under The Sea. It also goes by a more technical name, The Ocean Pole of Inaccessibility. But to the world’s space agencies, it is known as the South Pacific Ocean Uninhabited Area. Which makes it an ideal graveyard for end-of-life spacecraft.
More than a hundred Russian, Japanese and American craft are sprinkled over the ocean floor here over hundreds of kilometres. These include the remnants of the Mir space station – and it’s where the International Space Station is likely to end up when it’s decommissioned in 2024.
This week, Alice Gorman, an associate professor at Flinders University, explained to US podcast Atlas Obscura what happens when spacecraft reach the end of their lives.
As one of the world’s top space archaeologists, Gorman is also known as Dr Space Junk: space debris is her specialty, and the dangers it poses.
Some satellites simply turn into “zombies” when their work is done, she explains – whizzing around out of control and potentially destroying other craft. Once their electronic brains have expired, she says, they can’t be controlled – and can go rogue.
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“They’re after the electronic brains of the working satellites – but they can’t be controlled,” she says.
Smaller satellites or chunks of expired rockets can de-orbit all on their own or with some help from their controllers back on Earth, and they burn up on re-entry to the atmosphere.
Still others get directed further away from Earth – to the graveyard orbit, 36,000km above the planet’s surface.
“There has been a convention that when a spacecraft gets to the end of its life, enough fuel will be left in it to push it higher, so it will be out of the way of the satellites that are working,” Gorman says. “We call it a graveyard orbit. But they’re not dead under the Earth, they’re not buried – they’re ghosts. And ghosts don’t stay still. In fact, they’re haunting this orbit.”
Then there are those whose final resting point is back on Earth, surviving the plummet back through our atmosphere but guided towards a vast area of ocean where (hopefully) they can do no damage. After impact with the ocean’s surface, they sink so deep that no light can reach them.
Their remote “pilots” must precisely control their descent, and guide them all the way to the Space Cemetery. There are concerns about them, and their fuel, polluting the oceans – an issue scientists are working on.
Meanwhile, Gorman and her colleagues are working on mapping and exploring what’s down there. But she thinks the end, for the spacecraft, is not really the end. Like shipwrecks, they could end up “teeming with life”, with coral and fish, so they are “transformed into a habitat”.
It’s a thought that reminds Gorman of a passage from William Shakespeare’s The Tempest:
Full fathom five thy father lies;
Of his bones are coral made;
Those are pearls that were his eyes;
Nothing of him that doth fade,
But doth suffer a sea-change
Into something rich and strange.