miles」タグアーカイブ

Study based on Musk’s Falcon 9 finds rockets spew vast amounts of carbon 40 miles up

Study based on Musk’s Falcon 9 finds rockets spew vast amounts of carbon 40 miles up
Rocket launches emit lots of carbon dioxide and nitrogen oxides – pollutants with climate and health risks

A new study examining the polluting potential of rocket launches has found that space flights emit vastly more amounts of carbon dioxide in the upper atmosphere than typically exists.

While space flights are still only reserved for the privileged uber-rich, the report found that as the number of flights from Earth increase, so will the potential for significant pollution.

The study, published on Tuesday, modelled the fumes and exhaust of a rocket from launch up to 42 miles (67 km) into the atmosphere. The model was based on the Falcon 9, a rocket created by Elon Musk’s company SpaceX.

In the lower atmosphere, the amount of carbon dioxide (CO2) emitted by the rocket wasn’t substantial compared to the surrounding air, the paper found. That’s because the rocket is travelling very quickly, and the lower atmosphere has a denser concentration of gasses, including CO2.

However in the mesosphere, 30 -50 miles (50- 80 km) above Earth, the air is much thinner, and rocket exhaust is more noteworthy. Here, as the rocket travels 1km, it emits the same amount of CO2 as exists in 26 cubic km of the surrounding air.

CO2 is the planet-heating greenhouse gas driving the climate crisis. Space rockets also release nitrogen oxides (NOX), which can interact with water to create acid rain and damage fragile ecosystems. Nitrogen oxides like nitrogen dioxide and nitric oxide can be hazardous to health in high concentrations.

The Falcon 9 runs on a kerosene-based fuel which emits CO2 like any other fossil fuel. Bezos’ Blue Origin rocket, on the other hand, uses a hydrogen-based fuel that emits mostly water vapor (also a planet-heating greenhouse gas) and some nitrogen oxides, AP reports.

These findings should prompt rocket scientists to try to mitigate any potential climate and health impacts before launches become more common, Dimitris Drikakis, an aerospace engineer at the University of Nicosia in Cyprus and a study author told The Independent.

“In the short term, there is no concern because we are still at the experimental stage,” he said. “But in the longer term, where this will become a more common situation, then this is where the problem may arise unless we do something about it.”

Space flight has become increasingly trendy among billionaires like Jeff Bezos, Elon Musk and Richard Branson.

In July, Bezos traveled in the first, crewed Blue Origin flight – along with his brother, aviator Wally Funk and a teenager who paid $28million. Last month, SpaceX sent three private citizens to the International Space Station – the first time non-professional astronauts have visted the orbiting station – at the cost of $55million each.

Virgin Galactic, Richard Branson’s company, is reportedly charging the (relatively) less-expensive price of $450,000 per ticket.

But while so far limited to the very wealthy, these companies hope to make space travel more common – which can be seen as an exciting foray to push the boundaries of travel beyond Earth. But these launches are also a potential environmental disaster, possibly adding huge quantities of pollutants to an already spiralling climate crisis.

“We show that pollution from rockets should not be underestimated as frequent future rocket launches could have a significant cumulative effect on the Earth’s climate,” study co-author Ioannis Kokkinakis, a researcher at the University of Nicosia, said via a press release.

It’s unclear how much time it will take these gases to disperse in the atmosphere, according to the press release for the study, which was published in the academic journal, Physics of Fluids.

The impact on the atmosphere is also unclear, and may depend on where those gases end up. One study last year found that increased levels of greenhouse gasses in the mesosphere were causing that layer to cool down and shrink.

In addition to CO2, the new research found that rockets would also emit sizable amounts of nitrogen oxides in the lower atmosphere. Excessive amounts of nitrogen oxides can lead to serious respiratory issues as well as forming acid rain when mixed with clouds, according to the US Environmental Protection Agency.

Dr Drikakis called the current capabilities of the new rocket companies “amazing” – and hopes that they will use this kind of research to design more sustainable rocket systems.

While more frequent launches will likely influence the atmosphere, Dr Drikakis says, he’s unsure what that threshold of frequency is — and hopes that with sustainability in mind, rocket scientists can improve design to increase the number of rocket launches that can occur without damaging the planet.

“It’s very, very important to understand the negative effects that the pollution from rockets could have,” Dr Drikakis says, “in order to design better rockets, better fuels, and continue, uninterrupted, the evolution process of scientific discovery.”