Chemicals emitted into the atmosphere from burning satellites that are not working could damage Earth’s protective ozone layer if megaconstellations are planned to be built from tens of thousands of satellites such as SpaceX. Starlink“Proceed as expected,” the scientists warn.
Researchers also warn that poorly understood atmospheric processes caused by these chemicals could lead to uncontrolled geoengineering an experiment whose consequences are unknown.
For many years, the space community has been content with the fact that the amount of material burned up in the atmosphere as a result of Earth collisions with meteoroids far exceeds the mass of non-existent satellites, which have suffered the same fate. Even the growth of megaconstellations will not change this. However, the problem lies in the different chemistry of natural meteoroids compared to artificial satellites, according to Aaron Bowley, assistant professor of astronomy and astrophysics at the University of British Columbia, Canada.
“We receive 54 tons (60 tons) of meteoroid material every day,” said Bowley, one of the authors. article published on May 20 in Scientific Reports., – told Space.com. “With the first generation of Starlink, we can expect about 2 tons (2.2 tons) of dead satellites to return to Earth’s atmosphere every day. But meteoroids are mostly made up of rocks made of oxygen, magnesium, and silicon. meteoroids contain only a very small amount, about 1%. “
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Scientists have realized that megaconstellations have significant potential for changing the chemical composition of the upper atmosphere compared to its natural state. But not only that. Burning aluminum is known to produce alumina, also known as alumina, which can cause additional unexplored side effects.
“Alumina reflects light at certain wavelengths, and if you throw enough alumina into the atmosphere, you create scattering and ultimately change the planet’s albedo,” Bowley said.
Albedo is a measure of the amount of light reflected by a material. In fact, increased albedo of the Earth By injecting certain types of chemicals into the upper atmosphere, it has been proposed as a possible geoengineering solution that could slow global warming. However, according to Bowley, the scientific community has rejected such experiments because not enough is known about their possible side effects.
“Now it looks like we’re going to do this experiment without any oversight or regulation,” Bowley said. “We don’t know what the thresholds are and how this will change the upper atmosphere.”
Ozone Hole 2.0
Aluminum from satellites re-entry also has potential damage the ozone layer– a problem well known to mankind, which has been successfully solved with widespread bans on the use of chlorofluorocarbons, chemicals that were used in the past in aerosol cans and refrigerators.
In their article, Bowley and his colleague Michael Byers cite research from colleagues at the Aerospace Corporation, an American nonprofit research organization, that have identified localized damage to the planet’s ozone layer caused by the passage of polluting rockets through the atmosphere.
“We know that alumina really only destroys ozone when rockets are launched because many solid-fuel rockets use or have alumina as a byproduct,” Bowley said. “This creates these little temporary holes in the stratospheric ozone layer. This is one of the biggest problems associated with changes in the composition of the atmosphere that space travel can cause. “
The ozone layer protects life on Earth from harmful ultraviolet radiation. Ozone depletion in the stratosphere, the second lowest layer of the atmosphere extending at an altitude of about 7 to 40 miles (10 to 60 kilometers), has led to an increased risk of cancer and eye damage for people on Earth.
Gerhard Drolshagen of the University of Oldenburg, Germany, who has published articles on the effects of meteoroid material on Earth, told Space.com that returning satellites typically evaporate at altitudes between 90 and 50 km, just above the ozone-rich stratosphere. However, he added, particles created by the combustion of satellites will eventually sink into the lower layers.
Bowley said that as the alumina sinks into the stratosphere, it triggers chemical reactions that, based on current knowledge, are likely to cause ozone depletion.
Drolshagen, who was not involved in the recent study, agreed that since “satellites are mostly made of aluminum, the amount of aluminum deposited in the atmosphere will undoubtedly increase.”
Concerns about the effects of aluminum oxides on the atmosphere were raised by the US communications operator Viasat in a request to the FCC. suspend launches of SpaceX’s Starlink mega-constellation until a proper environmental impact assessment is carried out.
Learning from past mistakes
In their study, Bowley and colleagues only looked at the effects of the first generation of the starlink mega-constellation, which is expected to consist of 12,000 satellites. More than 1700 of them already launched. As a result of the activities of SpaceX (and, to a lesser extent, other operators of the constellation), the number of active and non-operational satellites in low Earth orbit, in space below 620 miles (1000 km), has increased by 50% over the past two years, according to message.
“The problem is that there are now about 55,000 satellites planned to be launched,” Bowley said. “A second generation Starlink could have 30,000 satellites, then you have Starnet, which is China’s answer to Starlink, Amazon Kuiper, OneWeb. This could lead to unprecedented changes in the upper atmosphere of the Earth. “
Mega-constellation operators, inspired by the consumer technology model, expect rapid development of new satellites and frequent replacements, so a large number of satellites are expected to burn in the atmosphere daily.
“People extremely well underestimate our ability to change the environment,” Bowley said. “There is a perception that we cannot dump enough plastic into the ocean to make a difference. We cannot release enough carbon into the atmosphere to change anything. But that’s all. We have plastic. the problem of ocean pollution, we have continued climate change as a result of our actions and changes in the composition of the atmosphere, and we are ready to make the same mistake using space. “
Astronomers, space debris and others
Mega-constellations are of great concern to the space community as they increase the risks of orbital collisions in pre-existing regions. cluttered orbital environment.
Starlink SpaceX, in particular, has also been criticized for the effect of their satellite’s visible plumes on astronomical observations. SpaceX has pledged to partner with the astronomical community and redesign its satellites to mitigate the problem… However, earlier this year, the International Astronomical Union asked a specialized UN committee to protect the clear night sky from light pollution from megaconstellations.
Last week, the head of European launch provider ArianeSpace, Stefan Israel, accused SpaceX mastermind Elon Musk of monopolization of space and crowding out competitors.
In addition to SpaceX, Musk has also gained recognition for his sustainability-focused ventures Tesla and Solar City, which aimed to help wean the world off fossil fuels. Earlier this year, Musk Announces $ 100 Million Carbon Removal X Prize, the richest honorable mention in history. The aim of the award is to develop technologies that can help prevent the worst effects of anthropogenic climate change.
SpaceX did not respond to Space.com’s request for comment.
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