Scientists stress that humanity needs to start solving the growing space debris problem now before it spirals out of control.
Earth’s orbit is becoming increasingly crowded, active satellite and fragments. There’s so much out there that it’s far from alarmist to start worrying about it. Kessler syndromea nightmare scenario in which one or two collisions lead to more collisions, greatly increasing the amount of garbage circling the Earth.
“We must take this issue seriously and recognize that unless we act, we face imminent danger, Earth Dan Baker, director of the Atmospheric and Space Physics Laboratory at the University of Colorado Boulder (UC-Boulder), said during a panel discussion at the American Geophysical Union (AGU) 2024 meeting on Wednesday (December 11): “The environment is unusable.”) in Washington, D.C.
There are more than 10,200 active satellites in Earth orbit, according to European Space Agency (ESA). Most of these spacecraft are located in low earth orbit (LEO), the outer shell located about 125 miles to 1,250 miles (200 to 2,000 kilometers) above the Earth.
Related: 7 Crazy Ideas for Cleaning Up Space Debris
Most low Earth orbit satellites— About 6,800 of them — belong to the same constellation: SpaceX’s Starlink Broadband Internet.
These numbers keep growing, and the numbers will soon become mind-boggling. For example, SpaceX hopes that the Starlink network will eventually accommodate more than 40,000 spacecraft.
Other players also plan to build their own broadband constellations in low Earth orbit. China has Start expansion If all goes according to plan, its Thousand Sail megaconstellation will have about 14,000 satellites. In addition, Amazon plans to build its own LEO broadband network of 3,200 satellites, called Project Kuiper.
These are just active satellites; the amount of junk in Earth’s orbit is much higher. For example, ESA estimates that there are approximately 40,500 debris objects at least 4 inches (10 centimeters) across that are whizzing around our planet. this space debris This includes an additional 1.1 million blocks with widths ranging from 0.4 inches to 4 inches (1 to 10 centimeters), and 130 million blocks with widths ranging from 1 mm to 0.4 inches.
Given the speed at which orbiting objects move, even these tiny pieces of debris can cause considerable damage to satellites or other spacecraft. exist international space stationFor example, its average altitude is 250 miles (400 km) and its orbital speed is about 17,500 mph (28,160 km/h).
The debris is too small to be tracked using ground-based radar. That’s a shame, scientists say — and not just because the debris is potentially dangerous.
“If Kessler syndrome starts to happen and we start to see a series of collisions, we would first See it in the smallest particles “These are our canaries in the coal mine. “
Malaspina and other team members said it’s difficult to quantify the risk of Kessler syndrome because the orbital environment is dynamic on several different levels.
First, the orbital population has been growing as rockets launch more and more satellites into space, so calculations become obsolete almost as soon as they are completed. and Earth’s atmosphereAs it slowly drags the LEO satellite through friction over time, it also changes – for example, in response to increased solar activity.
As you might expect, these satellites are increasingly coming into contact with each other and with debris. In fact, there are an average of about 1,000 collision warnings per day in low-Earth orbit, according to Thomas Berger, director of the Space Weather Technology Research and Education Center at the University of California, Boulder.
“So it’s increasingly difficult for satellite operators to determine which of these warnings are important and which they must heed,” Berger told an AGU panel meeting on Wednesday.
The vast majority of these warnings Involving Starlink satellitesthis is far from sitting still. The spacecraft use onboard software to detect potentially worrisome encounters and perform evasive maneuvers if needed.
But not every satellite that enters orbit has such capabilities. There are no globally enforceable rules forcing satellite operators to behave responsibly. Baker said this regulatory vacuum is leading to a “tragedy of the commons” situation.
“Simply put, the tragedy of the commons is that individuals acting rationally and individually in their own interests will deplete shared resources, even if it goes against the best interests of the group,” he said. “I believe we are seeing this firsthand Witnessing the tragedy of the commons unfolding in low Earth orbit.”
Baker emphasized that some of the resources being depleted are scientific, noting that large constellations of satellites could interfere with observation Made with visible light and radio telescopes. Some are cultural or social – for example, ordinary people’s enjoyment of the dark night sky.
Baker believes the United States should take the lead in developing guidelines to help avoid Kessler syndrome and the tragedy of the near commons. He noted that some progress has been made in this area, citing the recent launch of Bipartisan Orbital Sustainability Act (Track) in Congress.
“I think it starts at home and I believe we all have to play our part,” Baker said.