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Look out the window of your pressurized house into the deadly vacuum of space, and this
is the last thing you want to see.
But that’s exactly what astronaut Tim Peake saw earlier this year: a chip in the window
of the International Space Station. Thank science for quadruple-layered space glass.
Whatever made that mark was only half the width of a human hair. Not dust, or an intercepted
shooting star. It was an attack from Near-Earth Orbital Cosmic Debris!!!!
AKA space junk
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In the early days of the space race, the #1 priority was just getting stuff UP there,
preferably before everyone else. In the 60 years since Sputnik, there’s been
about 5,000 successful satellite launches, and more than 1300 are in operation today.
But we put a few hundred MILLION pieces of trash up there while we were at it.
Space debris comes in all sizes. We currently track about 17,000 man-made objects larger
than 10 centimeters, but for every one of those, there’s 10,000 too small to see on
radar.
Many of those invisible millions are things like flecks of paint, rocket exhaust, or metal
shavings, but those are all big enough to do damage. You can’t argue with kinetic
energy. When v is really, really big, a really, really small m can do bad things.
Only 1 in 10 tracked objects is an actual working spacecraft. If satellites were old
cars, Earth’s doorstep would look like Steven Avery’s front yard.
Two-thirds of space junk is close to Earth (reminder: that’s where space people live).
Among that we find the odd spatula or lost glove, but more than 10,000 bits of large
debris are left over from collisions or explosions.
In 2009, a US communications
sat collided with a dead Russian military satellite, creating more than a thousand new
pieces of large debris. Luckily, Sandra Bullock made it out OK.
If there’s any known object with more than a 1 in ten thousand chance of collision, NASA
maneuvers the ISS to safety, and one satellite or another is moved out of harm’s way on
almost a monthly basis. Unfortunately most objects in orbit can’t be maneuvered.
Exploding satellites are rare, but old rocket stages with unburned fuel have gone boom lots
of times. Explosions can also happen if you, say, fire a missile at a satellite… but
surely no one would do that, right?
Of course we would do that! In 2007, China destroyed one of their weather satellites
to test a kind of space battering ram weapon. That single collision made more than 2,300
pieces of debris larger than a golf ball, and millions too small to track. Everybody
got pretty mad at China for that, but the U.S. did the same thing in 1985 when it shot
down a satellite with an aircraft-launched missile.
But when it comes to the worst idea in the history of space pollution, perhaps nothing
compares to the summer of 1963, when we put a ring around Earth. Before the first satellites,
fast long-distance communication meant bouncing radio waves off of the high atmosphere, but
the quality was not great. We tried big shiny balloons as permanent radio reflectors, but
that didn’t really work. So the Air Force devised a plan to make the largest radio antenna
ever.
On May 9, 1963 the Project West Ford satellite released 20 kilograms of copper wire above
the Earth. It slowly formed a ring of metal between the north and south poles, too small
to see with the naked eye, but dense enough to bounce radio signals off of.
Those copper needles were very light, so most have probably fallen back to Earth, but thanks
to the extreme cold of space many of the Project West Ford needles were welded into clumps,
and are still orbiting Earth to this day.
The chance of any two pieces of debris running into each other are astronomically small,
but even one accident could be enough to spell disaster. In 1978, NASA scientist Donald Kessler
described a domino effect scenario, where debris from one collision would lead to other
collisions, each creating more debris and more destruction until nothing was left in
orbit: The Kessler Effect
We don’t know exactly what it would take to set off that chain reaction, but we may
have already put the pieces in place. And even if we stopped space launches today, we
still have to clean up what’s already there.
We've proposed some pretty wild ideas for dealing with all that space junk
Orbital harpoons, lasers, space tug boats
even a real life Pacman.
But all these remain ideas, none of them have gotten off the ground.
Only 6 or so people actually live up there, but space junk is a problem for all of us. Imagine life
without what’s up there. No satellites keeping trains, planes and automobiles running…
not to mention the power grid, communications, the global financial system… and definitely
no YouTube.
For a long time we’ve treated space like we used to treat the ocean. It’s really
big, so who cares what we dump there? Maybe it’s time for a little space environmentalism.
We’ll never set sail to distant lands if it’s too dangerous to step off shore.
Stay curious.