When you think of space, you think of just that… space.
Emptiness.
The Void.
But when it comes to the space around Earth, it’s actually not that empty.
It’s filled with a whole bunch of …. Junk.
Or space trash.
In fact, experts think that there are millions of pieces of debris in orbit — ranging in
size from bigger than a softball to smaller than a marble.
So what is all of this junk hanging out around our planet?
Well umm, that’s the awkward part: it’s all our stuff that we’ve put into space
that we just don’t use.
(Sorry, mom.)
That can be satellites that are no longer working, leftovers from rockets, or stuff
that’s come off of spacecraft over time — like panels or even flecks of paint.
Space debris has included some rather unique items too.
There’s a tool bag still up there that was lost by an astronaut during a space walk.
A lipstick-sized capsule of Gene Roddenberry’s ashes once orbited the globe for a while.
Even frozen pee used to make the rounds.
Before pee recycling systems came were put in place, astronauts used to dump their urine
out into space where they’d immediately turn into beautiful, shiny ice crystals that
reflected the Sun.
Sure that’s lovely and all, but just like trash here on Earth, debris in space can be
a big problem.
It makes the space around our planet a congested — and potentially dangerous — place.
You may think space debris is just floating out there all slow-like, but this stuff isn’t
really floating at all.
It’s actually zooming around Earth at more than 17,000 miles per hour.
That wouldn’t be a big issue if everything was moving in the same direction, but there
are a bunch of different types of orbits that space trash can be on.
Some go around Earth’s equator, while others go around the poles, for instance.
That’s where you run the risk of getting T-boned.
It happened in 2009, when a U-S satellite collided with one from Russia, putting thousands
of pieces of debris into space.
A similar event occurred in 2007, when China destroyed one of its satellites with a missile,
creating a whole mess of trash.
Okay so a little different scenario but the same result.
But even the smallest piece of trash travelling at such a high speed can cause a whole lot
of damage if it crashes into something.
And if collisions happen too often, then we run the risk of something called the Kessler
syndrome.
It’s a simple concept: colliding space objects create even more space debris.
And the more space debris, the higher odds of more collisions.
So if we don’t keep these accidents in check, it’s all going to snowball until we get
so much litter in space that the entire area is basically going to be hostile to spacecraft
for generations.
Our best defense against collisions is to basically know where all of this space trash
is.
Right now, tracking space debris is the job of the Defense Department.
It uses something called the space surveillance network — an array of telescopes entirely
dedicated to tracking objects in space and figuring out what they are.
The network is capable of tracking anything that’s bigger than 10 centimeters — so
about the size of a baseball.
And right now, more than 22,000 objects of this size are being tracked.
Once an object is spotted by the network, trackers must determine its orbit and then
see if it’s in the *~*catalogue*~*.
To get in the catalogue, trackers have to be able to identify a piece of debris all
the way back to its launch.
If you can’t, it’s called an uncorrelated track.
Or basically we don’t know what it is.
But ultimately the main goal is to know the odds of these pieces running into each other.
If a satellite has a 1 percent probability of collision, that’s way too high, and you’re
going to want to perform some orbit correction maneuvers with your thrusters to avoid an
accident.
Even the space station has to move out of the way sometimes when debris is in the area.
Of course correction maneuvers are really only an option for spacecraft with fuel to
spare.
Nothing can be done for debris without thrusters.
Plus there’s a whole ton of small objects that the surveillance network can’t see.
For those, experts have to create theoretical models to predict where these tiny pieces
are going to be.
So how do we clean up this mess?
Well for the satellites in lower Earth orbit, chances are they will come down eventually.
There are still air molecules in the upper atmosphere that create drag on spacecraft,
pulling them back down to our planet.
Those vehicles will mostly burn up on the way back down to Earth, but just in case,
the U-S has a policy that satellites have to have enough fuel leftover to de-orbit safely
when the time comes.
That means no satellites are going to fall on your head.
That only works for satellites in lower orbits though.
Many of our communications satellites are in a much higher region 22,000 miles above
Earth called geostationary orbit.
Those are way too high to come back down, so when they run their course, we put them
into a “graveyard orbit.”
It’s an orbit that’s 200 miles up.
The hope is that they’ll be far enough away to not interfere with operating satellites.
Those satellites will basically stay up there forever.
As for the getting rid of the rest of this stuff, people have come up with some creative
— and somewhat whacky — ideas.
There’s a concept known as the Terminator tether.
It’s a miles-long cable that interacts with Earth’s magnetic field, inducing a current
along the tether.
This creates drag on spacecraft on orbit, causing them to fall back to Earth.
It’s similar to an “electric whip” that Japan recently sent to space for clearing
out debris.
Other ideas include adding balloons or sails to spacecraft, to slow them down when they’re
done, or even shooting them with lasers.
The photons would impart a small thrust on the object, enough to bring it down.
There are a lot of other ideas too, but there isn’t anything really viable to solve this
problem right now.
So in the meantime, our best option is to get better at tracking this stuff, and that
job may soon switch hands.
The Federal Aviation Administration has been very vocal about wanting to take over the
job of debris tracking from the Defense Department.
So soon, the FAA may be the traffic cops of air and space.
There's also another way to protect against small debris that's moving pretty slow.
It's called: the Whipple shield.
And it acts like a bumper shock for things moving at 1 to 11 miles per second.
And the space station has over a hundred whipple shields on it.
So, it's good to go!