Humans are filling up the space around Earth with trash.
ARCHIVE: “three, two...”
Decades of space exploration that began with a single satellite launch in 1957...
ARCHIVE: “One of the great scientific feats of the age.”
Have left discarded rocket bodies, mission-related debris and thousands
of satellites – many of them long abandoned and no longer functional –
crisscrossing at high speeds just above Earth's atmosphere.
And with a booming space industry launching more objects into orbit
than ever before, this crowding is steadily increasing
the probability of catastrophic in-orbit collisions.
Scientists worry that a runaway chain reaction of collisions
and fragmentation could one day fill Earth's orbit
with so much debris that space will become unusable to humans.
It's why the world's leading space agencies and some for-profit
companies are working on big ideas to fix our space debris problem.
From trash collecting spacecraft armed with harpoons and nets...
to a giant cloud of metal dust.
And there's one solution that's been proposed for years
to halt these dangerous bits of garbage in their tracks.
Lasers.
Because if we get creative and start addressing this problem
right now, we can still fix it before it's too late.
The vast majority of human-made objects
surrounding Earth are here – in a region called “low Earth orbit.”
It's where we have communication satellites, plus spacecraft
like the International Space Station. And our massive amount of space trash.
The more objects we put in space means more chances of these objects
smash into each other, break apart, and multiply.
And all it takes is a handful of fragmentation events to dramatically
increase the total number of objects orbiting Earth. Like in 2009,
when a defunct Russian satellite accidentally collided
with a commercial satellite, exploding into thousands of trackable fragments.
And in 2007,
when China intentionally destroyed one of its own satellites in a weapons test.
Which also resulted in tens of thousands of fragments of varying sizes of debris.
A theoretical cascade effect called the "Kessler syndrome,"
introduced in the 1970s, warned that if enough incidents like these occur,
the fragments of debris they create could trigger
an uncontrollable number of catastrophic collisions.
Exponentially increasing the field of debris around Earth.
But we can still fix this before it's too late.
And there's a few ways it could happen.
The way to get rid of most space debris is to slow it down enough to fall
out of orbit and into Earth's atmosphere, where it burns up and is destroyed.
But different sized space junk requires different approaches to do this.
The biggest bits of space debris measure more than 10 centimeters in size
This includes dead satellites, rocket bodies
and big pieces of debris created during space missions.
These are large enough to be tracked from Earth.
And scientists are developing tiny spacecraft
that can reach these objects
and slow them down, using various methods to either push or pull them.
Guiding them down to Earth's atmosphere to be destroyed.
Commercial companies like Europe's ClearSpace
and Japan's Astroscale are working with global space agencies on this tech.
Hoping to demonstrate the removal of large debris sometime in the next decade.
The two smaller classifications of space debris mostly
come from fragmentation events like explosions and collisions.
Their numbers are estimates because we still don't have the technology
in place to reliably track debris below ten centimeters in size.
The tiniest pieces include flecks of paint and metal that even at a fraction
of a millimeter in size, regularly cause minor damage to spacecraft.
So far, scientists have proposed two main ideas to remove these.
One: a physical sweeper placed in orbit
that could catch or slow them down enough to de-orbit them.
But this approach for removal, at least as far as NASA's concerned,
is too expensive to even consider.
The other, more cost effective solution would be to release a cloud
of tungsten dust on top of the debris.
Which would coat the objects and weigh them down,
dragging them into Earth's atmosphere to be destroyed. On the other hand,
dumping a 20 ton cloud of heavy metal dust into Earth's
orbit could end up contributing to the pollution of space.
So it hasn't been tried yet.
As of right now, the sweeper and tungsten dust ideas probably aren't
practical solutions.
But there's another option for this class of space debris in the middle.
It presents a unique problem. Because at 1 to 10 centimeters,
this debris is too small to track, but big enough to do serious damage.
Just one fragment, even one centimeter in size, moving at an average speed
of seven kilometers per second is powerful enough to knock out a satellite.
Analysis from NASA shows that focusing on this range of debris
would be highly effective in managing the space debris problem as a whole.
This is where the lasers come in.
Lasers can direct a beam of energy and apply force to an object
without ever making physical contact.
They could be used to nudge a fast-moving piece of small debris
and disrupt its orbit – either knocking it into higher, less crowded levels of orbit,
or lowering it into Earth's atmosphere to be destroyed
This method is sometimes referred to as a "laser broom."
A ground-based laser system was proposed by NASA's Project Orion in 1996.
And according to NASA's 2023 cost and benefit analysis of space debris removal methods,
A ground- or space-based laser system
would be the most cost-effective way.
to remove this class of 1 to 10 centimeter size debris.
But historically, not everyone has loved this idea.
CLAUDE PHIPPS: People were resistant to the idea of lasers in space.
Because all the spy satellties were worried they might get blinded.
But now they starting to come around.
Claude Phipps was a part of Project Orion back in the nineties,
and is who originally proposed this idea in the US
to deal with space debris using lasers.
PHIPPS: It’s a fairly simple idea.
A ground-based laser for debris removal would basically work like this:
First, a radar system would detect a small piece
of debris coming over the horizon and lock onto its position.
Because while these objects are too small to track when out of sight,
they can be sufficiently tracked as they shoot across the sky long enough to aim
the telescope that focuses the laser and fire a near-instantaneous
pulse of energy through the atmosphere with remarkable precision.
A space based laser would work similarly, with a couple key differences.
One advantage of being in orbit is that these lasers
would have a more favorable angle to shoot debris downward into Earth's atmosphere.
And they wouldn't need to correct for Earth's atmosphere or long distances
when aiming – like a ground-based system would.
Making a space-based solution potentially more efficient.
But, being in space, it wouldn't have access to Earth's
power grid, and would be much more difficult to maintain.
PHIPPS: The laser on the ground is going to be cheaper.
But the geometry is kind of screwed up.
If you’re on the ground, you're having to shoot it this way
Whereas in space, you can see everywhere you know.
And hundreds of thousands of these things are available
when you’re in orbit.
Shoot this one, shoot that one, shoot the other one. As often as you want.
That same NASA cost and benefit report suggested that a laser system
could be highly effective for dealing with large debris too. By nudging the debris
out of the way of a spacecraft's orbit when an incoming collision is detected,
This method would be more cost effective
than sending spacecraft to retrieve the debris, and potentially
safer than dragging it back in Earth's atmosphere.
Since especially large pieces of debris aren't guaranteed
to be destroyed, and could pose a threat to people on the ground.
Claude told me that we have the technology now to develop ground- and space-based
lasers to fight space debris.
But there's one big thing that's standing in the way.
PHIPPS: It all comes down to money. It's not a question of knowing what to do –
it's a question of people committing to it.
There are a couple commercial companies
around the world working on it.
And we may not be so far away from a future where ground- and space-based
laser systems are sweeping the night sky of space debris.
There's one more problem we need to confront
before we start cleaning up space, though. Right now, international space
law forbids any body from touching an object in space that it didn't launch.
So even if a Japanese company like EX-Fusion or NASA do develop
a laser broom, they couldn't use it on a dead Russian satellite, for example.
PHIPPS: The lawyers have to work that out.
And where there's a will, there's a way.
That's the way I look at it.
Cleaning up this mess is going to require an international effort and cooperation
from commercial actors like SpaceX.
But removing what's up there isn't the only way to deal with the problem.
The European Space Agency's Zero Debris Charter, announced in June 2023, emphasizes
mitigation of space debris – preventing the creation of new debris going forward.
By committing to things like designing satellites
that reenter Earth's atmosphere on their own
after completing their missions – instead of sitting in space as trash.
In the US, the FCC introduced a new five year rule in September 2022 that said
US-based spacecraft put into low Earth orbit must de-orbit themselves
within five years of mission's end. Efforts like these are just the beginning.
But a combination of remediation and mitigation efforts is projected
to make serious progress in battling our space debris problem.
If everyone using space as a resource
can change their habit of littering before it's too late.
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