Since the launch of Sputnik I kicked off the space age in 1957,
our skies have steadily been filling up with more and more artificial satellites.
Right now, there are about 7,000 in orbit, and the pace of launches is only set to accelerate
as space travel gets cheaper and companies envision mega-constellations.
While space may be a pretty big place, there is a finite limit to just how much stuff can safely be whizzing around the Earth.
So, to paraphrase a song from my youth, what are we gonna do with all that junk,
all that junk in outer space?
And believe me, there is already a lot of junk up there.
Of those 7,000 or so satellites I mentioned, about 3,000 of them are defunct and not serving any purpose.
Some of them are huge, like ESA’s Envisat which is as big as a double-decker bus.
There have been several close calls as dead satellites guided only by the hand of physics nearly collided.
Sometimes they only miss each other by just a dozen meters, and sometimes they don’t miss at all.
Like in 2009 when an inactive Russian Cosmos satellite collided with a very-much active Iridium communications satellite.
That collision generated thousands of pieces of debris, and in space, the small stuff can’t be overlooked.
NASA estimates there are more than 23,000 pieces of debris larger than 10 centimeters in orbit around the Earth,
and there are hundreds of millions more pieces smaller than that.
Doesn’t sound very big, but at the extreme speeds they’re moving, they pose a risk to active satellites
and the International Space Station.
In fact, in May of 2021, astronauts inspecting the ISS discovered damage to the station’s robotic arm
that was caused by one of these tiny pieces of junk.
The arm is still functioning, but it could have been worse.
The worst-case scenario was imagined by NASA scientist Donald J. Kessler back in 1978.
The so-named Kessler syndrome is where more satellites like Cosmos and Iridium collide
and the resulting debris creates a runaway chain reaction that damages more satellites,
creating more debris that ultimately renders low-earth orbit unusable.
There are a few solutions in the works in an effort to stave off that bleak possible future.
A proof-of-concept for one of them launched in March of 2021.
The project, dubbed the End of Life Services by Astroscale demonstration, or ELSA-d,
is a collaboration between the Tokyo startup Astroscale and JAXA.
The demonstrator consists of two satellites, a larger one with a magnet
and a smaller one with a plate the magnet is designed to latch on to.
The two launched attached to one another but once all systems check out, the satellites will conduct a test in three stages.
First, they’ll split up and the larger one will attempt to recapture its counterpart.
If all goes well, they’ll split again, this time with the target satellite traveling in a tumbling orbit
that more closely mimics the behavior of space junk.
If they recouple a second time, they’ll split once more and the larger one will lose the smaller one.
Intentionally.
Now, If they manage to find each other and couple a third time,
the demonstrator will be considered a success and ELSA-d will deorbit and burn up in the atmosphere.
Even if all goes as planned, this system has its limits.
Astroscale’s approach to junk management requires the space junk to have that magnetic plate,
so while it could work for future satellites that incorporate it into their design,
it doesn’t solve the problem of the several thousand dead hunks of metal that are currently up there.
To tackle that issue, the Swiss company ClearSpace is developing a tentacled contraption
and aims to take down a large piece of an ESA booster rocket by 2025.
One other idea is to refuel dead or dying satellites in orbit,
eliminating the need to replace them or at least making it possible for them to move out of harm’s way.
NASA is planning one such refueling mission called OSAM-1 in the coming years.
Of course, there is another option and that is just…to not send up so many new satellites.
If space junk is allowed to come down at a faster rate than we put stuff up there, the skies will steadily become less crowded.
But with multiple companies planning global communication networks each made up of thousands of satellites,
that idea probably isn’t getting off the ground.
This issue is a long way from being solved.
There are so many satellites in orbit now that even if we stopped all launches,
some scientists believe the Kessler syndrome could still become a reality.
Space junk comes in such a wide variety of shapes and sizes
that no one approach will be the solution that cleans up low Earth orbit.
And these technologies could also have a sinister side:
something that de-orbits a junk satellite could also bring down an active one,
something that will no doubt concern governments and militaries of the world.
Doing something with all that junk is going to require a lot of creativity, trust, and forward-thinking
if we’re going to make sure there’s enough space in space.
If you’re curious why companies would want to create mega-constellations of satellites,
check out my video on SpaceX’s Starlink project here.
Are you worried about the Kessler Syndrome going from scary hypothetical to reality?
Why or why not?
Sound off in the comments, be sure to subscribe, and I’ll see you next time on Seeker.