Space junk is a trap that can surround humanity on Earth

Today, NASA estimates that there are About 100 million pieces of space debris over one millimeter in diameter At different altitudes in Earth’s orbit.

Astrophysicists fear, however, that this number will grow exponentially, given the thousands of satellites from private companies that will be launched in the next few years.

The only starlink from South Africa Elon Musk, has already secured permission from the US government to put 42,000 satellites into orbit over the next few years, nearly 2,000 of which have already been launched.

The company claims that after it went out of business, Equipment should take between one and five years to disintegrate.r in the Earth’s atmosphere without significant complications and without causing harm to the population.

In fact, the chance that a piece of space junk could resist Earth’s atmosphere and cause some damage is very small. second to ESA, the probability of a person being struck by lightning is 60,000 times greater than the probability of being surprised by the shrapnel of a missile falling on his head.

Only one such case was recorded, in 1997, with American Lottie Williams, who was unharmed.

What experts worry about launching huge constellations like Starlink is actually how much potential space junk is being released into space.

“Satellites stop working for a number of reasons, and if they’re not working and we can’t control them, they can drift and crash into things,” Gorman says. “A lot of debris is pulled into the atmosphere, but this could take weeks, months, and even years.”

Difficult solutions to clean the place

To speed up this process, the Japanese company Astroscale is working on several commercial spacecraft responsible for “cleaning up” space.

The goal of this technology is to capture extinct satellites in higher regions of Earth’s orbit and bring them closer to Earth, accelerating the re-entry and disintegration of these objects into the atmosphere.

The company plans to implement the technology in 2024, and to that end, it began conducting tests in orbit around the planet in August of this year. The prototype, called Elsa-d, consisted of two satellites working together, and in this first stage, demonstrated the ability of its magnetic system to trap and release debris.

Other solutions for removing space debris have already been proposed by engineers and astrophysicists from different countries.

While options range from networked rockets to pick up retired satellites to equipment with lasers for “garbage evaporators,” none of them have proven viable so far.

The reason is that creating technologies for harsh and unstable conditions like those around Earth is no easy task. Under these conditions, even something seemingly simple, such as maintaining constant contact with equipment that is in orbit for a few minutes, can be very complex.

As Astroscale spokeswoman Alison Howlett explains, for the Elsa-d procedure to work, the control system on Earth must remain in contact with the spacecraft for 30 minutes, four times longer than it normally takes to perform routine actions on satellites.

“Overall, the Elsa-d mission is very complex,” Howlett says. “But we hope that these technical presentations will show commercial and government clients that we have the technical resources to provide this service.”

However, eliminating space debris by accelerating its return and disintegration in the atmosphere is far from an ideal alternative.

Hazards to the Earth’s environment

One A study issued by the Aerospace Corporation The North American Geophysical Union, in December 2020, reports that there is a high chance that the combustion of the materials that make up satellites and missile parts will harm the environment.

The research authors claim so Not much is known about the end of the space junk components Because they burn up in Earth’s atmosphere, but they estimate that 60% of rocket bodies and 60% to 90% of the mass of satellites disintegrate in the process.

They also believe that aluminum is a large part of the material that burns – and that’s where the danger lies.

Elements such as aluminum can react with elements already in the Earth’s atmosphere, heating it up and damaging the ozone layer. However, “without accurate modeling, the exact extension [desse problema] unknown,” the scientists wrote in the study.

Also, according to the article, if all the expected satellites were launched, between 800 and 3,200 tons of garbage would be burned in the atmosphere each year, compared to 100 tons per year today.

A space without rules

Another aspect to keep in mind is: Not everything that doesn’t work there is rubbish. As Alice Gorman notes, many things have historical and cultural value.

An example is the American satellite Vanguard 1. Launched in 1958, the object that orbits the planet for the longest time. “Technically, it’s a piece of junk space, but its cultural meaning is being there,” Gorman says.

According to the Outer Space Treaty established by the United Nations (UN) in 1967, space belongs to everyone. So having a broader, less nationalistic sense of extraterrestrial achievement is critical to solving problems like space junk — but that’s not always the case.

Aside from the treaty, the only instrument that guides to some extent good extraterrestrial practice is the 1972 Convention on Liability for Damage Caused by Space Objects. However, none of them actually regulate space activities, according to Nigerian Temibe Aganapa, who specializes in the spatial domain. judgment.

“This is the big issue we have with international law, because there is no ‘international police’; there is no authority higher than the state,” explains the researcher, who also teaches at Arizona State University in the United States. That way states choose whether or not they are linked. [a tratados e acordos] And choose whether or not to follow them.”

Nor is there exactly a “punishment” for those who don’t stick to the conventions.

Moreover, due to the millions of space debris fragments in orbit, it is difficult to identify the culprits of any accidents. The exception is when something like the Russian anti-satellite test in November happens — and even then, harsh reactions from other governments may not be very comforting.

“All countries want to keep their freedom off the ground and will not be the first to exaggerate the condemnation of any measure [como a da Rússia], because they also want to be able to implement it,” Agnapa describes.

But since occupying the universe – for political reasons or not – seems to be of great interest to many countries, the solution to the space debris problem should be.

“Our experience shows us that the more human activity increases a lot in a given environment, it deteriorates,” explains the researcher. “So why don’t we think of solutions now in the beginning, when we are only in the beginning and the risk of accidents is low?”