Have you ever noticed the streaks of light flashing across the sky? These are not astronomical phenomena, but rather the numerous satellites of Space X, the space company owned by South African billionaire Elon Musk. We will explain to you what this constellation exists for and why there are so many of them. Published October 4, 2023.
As night falls, strange streaks of light appear in the sky, flashing and receding.
These are neither aliens nor shooting stars, but rather constellations of satellites created by Space
To help us, we sought the advice of Cyrille Menudier, a researcher at the XLIM Institute in Limoges.
When can we observe these light trails?
The easiest way is to observe them at night. We can see successive points that are well aligned and moving away. Those are Satellite constellations, a technology called Starlink developed by SpaceX. Only then will we see her, before settling into their final orbit.
“When the rocket arrives in space, the satellites inside are deployed. In the same rocket there can be thirty to fifty. They are ejected from the launch vehicle and strategically positioned at very even intervals. This is called a post. It's as if we were driving on the highway and trying to queue up vehicles without interrupting the flow of traffic and without the risk of a collision,” explains Cyrille Menudier, researcher at the XLIM research unit at the University of Limoges.
What are these satellites used for?
In reality, these satellites are useful to us every day: they enable us Very fast internet connection. SpaceX has been using them in space since 2019. An innovative technology that Cyrille Menudier explains to us:
“SpaceX found an idea that everyone thought would be difficult to implement: Take the satellites very deep into space. Instead of the satellites we used to watch TV when we had a dish being 36,000 kilometers away, they are now just a few hundred or thousands of kilometers above us. The wave therefore spreads faster. For very fast internet it is very effective, but provided that there are many satellites covering the entire planet. »
Why did they invade heaven?
If we see so many of them, it's because they have literally invaded our heaven: Around 5,000 satellites were sent into space in four yearssaid the researcher. According to France 2, there will be 12,000 by 2025.
This is the state of this system: “As the satellites are lower, they no longer have a fixed position, unlike those 36,000 kilometers away.” We can no longer have a single fixed satellite monitoring the entire planet. You are forced to create constellations of satellites that constantly move above our heads, which is quite problematic. For this to work, a certain density of satellites is required. It doesn't take a dozen, but thousands », assures Mr. Menudier.
These thousands of satellites: a problem?
This astronomical amount of satellites poses two main problems: it contributes to space pollution and can have geopolitical consequences.
While previously only states sent satellites and regulation between them could be carried out without any problems, today Private players like SpaceX are getting involved and this could one day be a problem. No authority regulates traffic, so there is a risk of collision even if a check is ordered: ” Imagine the impact if a Russian satellite collides with an American satellite… And how can we be sure that these private actors are properly responsible for the operation of their satellites? If you send a satellite, you are responsible for it. You do not have the right to send a satellite into space if you are unable to monitor its development behind the scenes. It's a bit like customer service. Knowing that a small satellite like SpaceX's only lasts a few years. »
According to La Dépêche du Midi, 236 Starlink satellites disappeared this summer. “For this reason, a major project is currently underway to develop some kind of space law in view of this growing number of satellites » says the researcher.
Has SpaceX revolutionized the space sector?
According to researcher Cyrille Menudier, Elon Musk's company has put a “kick in the anthill.” SpaceX has completely upended the techno-economic model in the space sector by reducing satellite and launch costs while still producing interesting achievements.. »
“Unlike the big manufacturers who specialize in rockets, satellites or their operation, at SpaceX they have control over everything. They build their satellite, their rocket, they control all the launch costs,” explains Mr. Menudier.
A start ?
The least reassuring thing about this story is that it doesn't end there. More satellite constellations, this time called Kuiper, are expected to land in space soon. Original: Jeff Bezos, the billionaire who runs the Amazon empire.
How to see Starlink satellites?
It is possible to locate, identify and track Starlink satellites: