Friday , February 3 2023

Space tourism can pose a threat to the ozone layer and the climate


Amazon founder and multi-billionaire Jeff Bezos, on July 20 this year, 52 years after Neil Armstrong’s first step on the moon, after flying into space, my expectations were very high, and I exceeded them.

Already 20 years ago, the first space tourist, American Dennis Tito, paid the ISS International Space Station the equivalent of 150 million SEK to accompany the Russian space capsule.

Jeff Bezos 2021 while flying into space in 2021.

Jeff Bezos 2021 while flying into space in 2021.

Photo: TT

However, 2021 will go down in history as a year in which space tourism began in earnest. British billionaire Richard Branson flew into space a week before Bezos with the Virgin Galactic spacecraft VSS Unity. And on September 19, the first space capsule with only tourists landed after three days in orbit around Space X’s Dragon spacecraft.

Since the 1960s About a hundred missiles are launched a year. But now Richard Branson, Jeff Bezos and Elon Musk and their companies Virgin Galactic, Blue Origin and Space X are considering offering space travel to paid tourists, a number that will increase significantly. The consequences can be serious.

– For example, a rocket launch with Space X emits about 100 times more carbon dioxide per passenger than a flight over the Atlantic Ocean. So you can imagine that if space tourism becomes commonplace in the future, it could have a negative impact on the climate. Atmospheric chemist Robert Ryan of the Department of Geography at University College London says we haven’t gotten there yet.

A family takes a selfie in front of a rocket on the edge of Space X's headquarters.

A family takes a selfie in front of a rocket on the edge of Space X’s headquarters.

Photo: Nicklas Thegerström

Space tourism not only increases the concentration of greenhouse gases in the atmosphere. It also threatens the ozone layer, which protects from the sun’s dangerous ultraviolet radiation.

Robert Ryan says that rockets are the only thing that humans directly emit into the stratosphere, the part of the atmosphere where the ozone layer is located.

In 1985, a hole in the ozone layer over Antarctica was discovered. Two years later, the Montreal Protocol was signed limiting the use of ozone-depleting freons and other substances.

– Over the last 20 years, the ozone layer has been slowly improving. Robert Ryan says what worries us the most now is that rocket waste will destroy part of it.

He and his colleagues calculated what space tourism meant for the atmosphere and climate, based on the fuels used and the companies’ predictions of how much space travel they could offer. As the study has not yet been published, Robert Ryan cannot give a detailed conclusion.

– But in general, we see that the emissions in the upper part of the stratosphere, which may have a large number of rocket launches, will damage the work done to repair the ozone layer through the Montreal Protocol.

The SpaceX rocket Falcon will take off on September 9.

The SpaceX rocket Falcon will take off on September 9.

Photo: Joe Raedle / TT

Which substances are released depends on the fuel used by the missiles. It emits chlorine called solid rocket fuels.

Chlorine emissions into the stratosphere are especially dangerous for the ozone layer. At the time of the first discovery of the ozone hole, it was mainly chlorine molecules that caused the ozone layer to be depleted.

Neither Virgin Galactic, nor Blue Origin, nor Space X rockets use solid fuel.

– They do not emit any chlorine, other chemical compounds. Robert Ryan says we are primarily concerned about nitrogen oxides.

Nitrogen oxides are partly derived from fuel, but are also formed from nitrogen in the air when heated to high temperatures. .

The rockets emit smoke and other particles that affect both the climate and the ozone layer.

– But so far it is impossible to compare the climatic impact of missile launches with aviation waste, because not many missiles have been launched yet.

What’s in the rocket smoke?

The cloud formed when the rocket is launched consists of water flowing in the runway, but the fuel can also contain carbon dioxide, aluminum and chlorine (in the form of hydrochloric acid). Rockets higher in the stratosphere emit nitrogen oxides, tu, aluminum and chlorine, which can damage the ozone layer. Rocket emissions are the only emissions we have direct access to the stratosphere where the ozone layer is located.

What's in the rocket smoke?

Källor: Cleaner Journal, Clean Technica, Daily Astronaut.

Rocket fuels The space age has developed a lot since childhood.

– Kerosene fuels have been used for a long time and are still widespread. Robert Ryan says it’s mostly refined gasoline, a highly refined form of the product we use in cars and planes.

Other missiles use liquid hydrogen as fuel.

– It is spreading more and more. Such fuels emit water vapor, not carbon dioxide, so they can be milder to the climate. However, they still produce nitrogen oxides that can damage the ozone layer.

Water vapor is also a greenhouse gas, but so far the impact on the climate seems minimal.

– The stratosphere is a dry part of the atmosphere, so there is a potential risk. However, the missiles do not emit enough water vapor to give the desired effect. There could be a problem with the launch of many more missiles. But it is not clear. Robert Ryan says it’s clear that nitric oxide and chlorine can damage the ozone layer.

At the same time rockets and space programs absolutely essential for climate and environmental research.

– Satellites are becoming increasingly important for climate science and air pollution research. There are many satellites in orbit with measuring devices for greenhouse gases and other atmospheric chemicals.

Researchers need to understand what air pollution looks like in different places and how it affects human health, and where and how much greenhouse gases are emitted.

– But we cannot have measuring stations all over the world. Protection is really expensive and time consuming. Robert Ryan says research undoubtedly needs satellites that can track the entire planet in space, both now and in the future.

But rules are also needed to protect the ozone layer and the climate.

– There is no law on what kind of fuel can be used, how many missiles will be fired and by whom. We need to start thinking about it. Robert Ryan says we are now at the beginning of a new era in space tourism.

Missiles against the plane

Missiles against the plane

Source: Daily Astronaut

The space tourism market is expected to grow by 2031.

(Million dollars)

The space tourism market is expected to grow by 2031.


Robert Ryan, Atmospheric Chemist, University College London.

Robert Ryan, Atmospheric Chemist, University College London.

Photo: Private

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