The chemicals released when a dead satellite burns into the atmosphere could damage the Earth’s protective ozone layer. If there are plans to build a huge constellation of tens of thousands of satellites like SpaceX. star linkGoing forward, as predicted, scientists warn.
The researchers also warn that poorly understood atmospheric processes triggered by those chemicals could lead to uncontrollable effects. geoengineering An experiment with unknown consequences
For many years, the space community has been pleased with the fact that the amount of material burning in the atmosphere as a result of Earth encounters with meteorite Much more than the mass of expired satellites that met the same fate. Even the growing mega constellation can̵7;t change that. The problem, however, lies in the different chemical composition of natural meteorites compared to artificial satellites, according to Aaron Boley, associate professor of astronomy and astrophysics at the University of British Columbia, Canada. say
“We have 54 tons (60 tons) of meteorite material coming in every day,” said Boley, one of the authors of The paper published May 20 in the journal Scientific Reports.Tell Space.com, “With the first Starlink, we can expect approximately 2 tons (2.2 tons) of dead satellites to return to Earth’s atmosphere every day. But most meteorites are rocky. They are made of oxygen, magnesium and silicon. Most of these satellites are aluminum, which Meteorites are only very few, about 1%.”
Related: SpaceX’s Starlink satellite megaconstellation launched in photos
Scientists recognize that large constellations have significant potential to alter the chemistry of the upper atmosphere compared to natural conditions. but not only that The burning of aluminum is known to produce aluminum oxide, also known as alumina, which can provoke further unexplored side effects.
“Alumina reflects light at a certain wavelength. and if you dump enough alumina into the atmosphere You will eventually create scattering and change the planet’s albedo,” Boley said.
Albedo is a measure of the amount of light reflected by a material. in fact, Add the world’s albedo By pumping certain chemicals into the higher atmosphere, it has been proposed as a possible geographic solution that could slow global warming. However, Boley said the scientific community has rejected such an experiment because it does not. Adequate knowledge of potential side effects
“Right now, it looks like we’re going to do this experiment without any control or regulation,” Boley said. “We don’t know what the threshold is. And how will it change the upper atmosphere?”
Ozone hole 2.0
Aluminum from satellite re-entry also has the potential to destroy the ozone layerwhich is a problem known to mankind This was successfully solved by prohibiting the use of chlorofluorocarbons. The chemicals are widely used in sprays and refrigerators.
In their article, Boley and his colleague Michael Byers cite research by their colleagues from Aerospace Corporation, a US nonprofit research organization. which identifies local damage to the planet’s ozone layer caused by the launch of polluting rockets into the atmosphere.
“We know that alumina destroys ozone by launching a rocket on its own. Because many solid fuel rockets use or there is alumina as a by-product,” Boley said. “That creates tiny temporary holes. these in the ozone layer in the stratosphere. That is one of the biggest concerns about changes in the atmospheric composition that space flight can cause.”
The ozone layer protects life on Earth from harmful UV rays. ozone depletion in the stratosphere It is the second-lowest atmosphere, extending between altitudes of about 7 to 40 miles (10 to 60 kilometers), leading to an increased risk of cancer and damage to human eyes on Earth.
Gerhard Drolshagen of the University of Oldenburg, Germany, who has published a paper on the impact of meteorite material on Earth, told Space.com that reentry to the satellite usually evaporates at altitudes between 55 and 30 miles (90 to 50 km). ) which is above sea level. ozone-rich stratosphere, however, he added. The particles generated by the combustion of the satellite eventually sink to the lower layers.
Boley said that when alumina sinks into the stratosphere, It will cause a chemical reaction. which according to the existing knowledge likely to cause ozone destruction
Drolshagen, who was not involved in the recent study, agreed that because “Most satellites are made of aluminum. The amount of aluminum accumulating in the atmosphere will certainly increase.”
Concerns about the effects of aluminum oxide on the atmosphere were cited by US telecom operator Viasat in a request to the US Federal Communications Commission. Suspend SpaceX’s Starlink megaconstellation launch Until the potential impacts of the environment are properly reviewed.
Learn from past mistakes
In their study, Boley and his colleagues looked only at the effects of the first Starlink constellation. which is expected to consist of 12,000 satellites. More than 1700 items has been launched As a result of SpaceX’s activities (and, to a lesser extent, of other constellation operators), the number of active and defunct satellites in low-Earth orbit. Areas of land below 620 miles (1,000 km) of altitude have increased by 50 percent over the past two years, according to the report.
“The problem is that there are currently plans to launch about 55,000 satellites,” Boley said. “The second-generation Starlink could consist of as many as 30,000 satellites. Then you have Starnet, which is the Chinese response to Starlink, Amazon’s Kuiper, OneWeb. This could lead to unprecedented changes in the Earth’s atmosphere.”
Megaconstellation providers inspired by consumer technology models. Expect new satellites to develop rapidly and require frequent replacement. Therefore, many satellites are expected to burn in the atmosphere each day.
“Humans are very good at underestimating our ability to change the environment,” Boley said. “There is this perception that there is no way we can dump enough plastic in the ocean to make a difference. There’s no way we’re leaving enough carbon in the atmosphere to make a difference, but here we have plastic, the pollution problem in the oceans. We are constantly changing climate as a result of our actions and changes in the composition of the atmosphere. And we are ready to make the same mistake by using our space.”
Astronomers, space debris, etc.
Megaconstellations This has caused great concern to the space community as it already increases the risk of in-orbit collisions. cluttered orbital environment
Specifically, SpaceX’s Starlink has also come under fire because of the impact of their satellite’s visible train on astronomical observations. SpaceX has pledged to collaborate with the astronomy community and fix their satellite designs to alleviate the problem. However, earlier this year The International Astronomical Union asked a United Nations specialized committee. to protect the pure night sky Against light pollution from large constellations
last week ArianeSpace’s head of European launch provider Stephane Israel accuses SpaceX’s Elon Musk. monopoly area and encroach on competitors
In addition to SpaceX, Musk is recognized by sustainability-focused ventures such as Tesla and Solar City. The goal is to help the world stop using fossil fuels. at the beginning of this year Musk Launches $100 Million Carbon Removal X Prize,The Richest Incentive Prize in History The goal of the award is to develop technologies that can help prevent the worst effects of human-caused climate change.
SpaceX did not respond to Space.com’s request for comment.
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