Transcriber: Kahori Tomiyoshi Reviewer: Elisabeth Buffard
Close your eyes.
Imagine yourself in outer space.
It is completely dark.
Except for the distant glow of our beautiful planet, Earth.
As you open your eyes,
you can see thousands of tiny bright lights
orbiting our planet.
They are satellites, tools that us, Earthlings have put there
to enhance our life from above.
Satellites have become such an essential part of our daily life
that we often forget how much we rely on them to make life run smoothly.
They allow us to travel the world
without getting lost in the middle of nowhere, most of the time.
They observe and protect us by predicting the weather
and monitoring climate change.
But most importantly,
they allow us to connect with each other
by providing internet to the people in the remotest part of the world.
Even up in the skies
when we are flying to our travel destination.
Space has been providing us many ways to explore beyond our wildest imagination.
Just like in science fiction movies, where fiction has become reality.
For instance, let’s visit our neighbor, the Moon.
We are currently building a station around it called the Gateway,
and in the near future, we foresee to build a Moon Village,
using the resources directly available there and relying on robots
that we can either control from Earth or from this future station.
This is how much space enables us to achieve.
If we come back closer to Earth now.
As of now, we count 5,000 satellites around it.
But only 40 percent of them are in operation.
Why?
Because the rest of them have become space debris.
Not only has the number of satellites doubled over the last 3 years,
but also the amount of space debris,
which constitute 60 percent of the existing satellites in orbit.
More than 10,000 satellites are going to be launched
in the next 10 years alone.
Yet there are already 34,000 pieces of debris,
bigger than 10 centimeters, around the Earth.
If we add to that the smaller bits,
we can count more than 130 million pieces bigger than one millimeter.
So if we add up the masses, we obtain the Eiffel Tower.
It is like having a direct staircase to heaven.
It is starting to look like a wrecking yard.
If I were an astronaut,
somewhere in my dreams,
I would be quite scared to go up there.
Human missions in space is already quite complicated.
Space is already quite a hostile environment,
but if you also have to dodge bits of debris
or end up in a situation like the movie Gravity,
where you see a piece strike the International Space Station
and everything going haywire,
you can imagine how difficult it might be
to perform any kind of operations in space.
Besides, it also puts
the existing satellites we used to monitor Earth with in jeopardy.
So what can we do?
We still need satellites,
but we don’t want to add up to the 60 percent of debris.
So space professionals like me are imagining new kinds of missions.
These missions need to be smarter
and innovative in order to first counteract
the growing populations of satellites and better manage the future in space.
Doesn't this look a bit familiar?
It seems like we are reproducing the same mistakes that we have done on Earth,
where we have done a lot of things very quickly
without thinking too much about the consequences.
And now we are trying to reverse back to a more sustainable lifestyle.
What could be the solution in space?
We have to do on orbit servicing.
It is a way of directly managing satellites that are already in orbit.
A satellite at the end of its life,
it’s either going to die in a graveyard orbit,
- this is the case for geostationary satellites called GEO, in short,
that are at 36,000 kilometers in altitude -
or they’re either going to disintegrate themselves as they enter the atmosphere.
This is the case for low earth orbit satellites
that are between a few hundred and a thousand kilometers.
A GEO satellite is designed to last between 10 to 15 years.
But if something happens,
there’s no way we can send an astronaut to repair it.
First, it is very expensive,
and second, also very dangerous.
Besides, it would require more than a thousand astronauts
like Thomas Pesquet or Samantha Cristoforetti
to perform these operations.
We cannot really ask them that now, can we?
So what else can we do?
Usually, if something goes wrong, we call customer service.
Well, we are not so far.
We would need a special vehicle called a servicer.
It's a super space vehicle
with a robotic arm, various tools, gripper...
First, it will inspect the environment of the client's satellite,
then perform a rendezvous to capture the spacecraft
and execute the required operations.
It can be capturing it to help with its attitude,
what we call station keeping.
It could be refueling, repairing or upgrading.
A satellite, at the end of its life, as I said, for GEO satellite,
they’re going into a graveyard orbit.
So the servicer can also help the satellites reaching their end of life
by putting them in a graveyard orbit
or for the lower satellite orbit,
putting them back towards the Earth for them to disintegrate.
All this helps us become more sustainable in space.
First, if you attend to the satellites in orbit and extend their lifetime,
you’re delaying sending up a new spacecraft
and to fully replace it in the future.
And second, if you attend
to the satellites that are reaching their end of life,
you have less satellites that becomes uncontrolled debris.
Thus, as a result, we become more sustainable.
But, in order to enable this,
advanced operations in space could be refueling or upgrading,
you need to prepare your satellites from now on
with specific interfaces like grapple fixture or interfaces
that would require for refueling or upgrading.
It is a bit more complex to perform it on an unprepared spacecraft.
Still feasible but more complex.
Us humans always want to do bigger and better things,
we like to run ambitious missions at an ever faster pace.
But it’s not necessarily in the most well-thought out way,
and reversing back is not always an option.
We have entered a new era of space system with an easier access to space,
and where several megaconstellations are foreseen to be launched
to tackle the growing internet needs on Earth.
So we are compelled to innovate,
invent new technologies and devise the smartest of missions
to follow this trend.
Or should I say, keep up as much as we can with this trend?
This is the bright side of things, because in the end,
we progress on amazing technology
that will also be useful and applicable for future space exploration
and for the benefit of humankind.
Nonetheless,
as we look forward developing servicing missions,
it allows us to take a step back,
think
and be smarter about the way we exploit outer space
to create a sustainable environment,
following the path on what we are trying to do on Earth.
After all, everything we do up there is for the benefit of us down here,
so it’s in all our interests to get it right.
This contributes to life on Earth, to space for life.
Thank you.
Merci.