Like Blue Race, SpaceX, the Virgin Galactic space race could affect the atmosphere

The space industry is taking off after decades of stagnation.

Driven largely by Elon Musk’s rapidly developing SpaceX and China space programs, the world recorded 114 orbital launches in 2018, the first three-digit sample since 1990. This year, orbital launches surpass 130 for the first time. time since the Seventies. And that count doesn’t include Jeff Bezos ’recent Blue Origin suborbital tourism excursions and Richard Branson’s Virgin Galactic.

Between NASA planning its lunar return, SpaceX is building a massive “megaconstellation” of Internet satellites, China preparing a space station and suborbital companies sending teams of tourists to the edge of space , launches could soon become a daily occurrence.

But will the new space boom have a price for the planet?

“While we obviously need space and satellite launches, when it comes to things like space tourism, you start thinking about the environmental impact,” says Ian Whittaker, a professor of space physics at the University of Nottingham Trent in the United Kingdom. United.

Researchers are struggling to figure out how the Earth might react to more undulating rocket escape feathers by studying the global mix of carbon dioxide, soot, alumina and other particles spilled collectively by a proliferation of rockets.

So far, the fledgling space industry is not seriously threatening the environment and probably has room to grow. However, if that will change as the new space race accelerates, whatever it is.

“I don’t think we know enough right now to establish exactly what that future should be like,” says Martin Ross, an atmospheric scientist at The Aerospace Corp. “We just don’t have that information yet.”

As the world faces the transition from fossil fuels, the rise of a new industry, especially one involving giant clouds springing from powerful engines, may seem troubling.

Most rockets emit more carbon that heats the planet than many aircraft. Experiencing a few minutes of weightlessness on the Virgin Galactic spacecraft will accumulate a carbon footprint comparable to the business class flying across the Atlantic and an orbital launch of SpaceX’s next reusable spacecraft will emit both carbon dioxide and fly a plane continuously for about three years. , according to a calculation on the back of the Whittaker envelope.

A Virgin Galactic spokesman said the company “is examining opportunities to offset carbon emissions for future customer flights.” Although SpaceX has not commented directly on carbon emissions, Musk has supported a carbon tax policy. Blue Origin has said its New Shepard rocket uses carbon-free fuels such as hydrogen and oxygen.

But there are far more commercial aircraft flights than space launches (39 million compared to 114 in 2018, respectively), too much for the space industry to catch up on even the most ambitious scenarios. Today, rockets collectively burn approximately 0.1% of fuel as aircraft do, making their carbon emissions a rounding error in comparison.

Whittaker notes, however, that these calculations neglect the unknown but likely carbon footprint of producing, transporting, and cooling the tons of tons of fuel used in space launches.

“While it doesn’t match aviation, it’s still a great addition,” he says.

To achieve carbon neutrality, it expects the industry to follow Blue Origin’s leadership and use carbon-free fuels as well as reverse operations, producing fuel locally from renewable energy sources.

“If CO2 isn’t where the action is, it’s the particles,” says Ross, who has spent decades studying the environmental effects of releases.

The glowing flames of a rocket’s engines indicate that the vehicle’s burning produces soot, technically known as “black carbon”. Any rocket that burns carbon-based fuels such as kerosene or methane injects these particles directly into the upper atmosphere, where they are likely to circulate for four to five years.

There, the growing layer of soot acts as a thin black umbrella. It absorbs solar radiation and effectively prevents sunlight from reaching the planet’s surface, just as the proposed geoengineering schemes intended to temporarily cool the Earth could work. The bright alumina particles emitted by the solid rocket engines used by NASA’s upcoming space launch system and China’s long March 11 vehicle exacerbate the phenomenon by reflecting sunlight.

The effects of this unwanted experiment are unknown, other than that they could be substantial. A simple simulation by Ross and a co-worker in 2014 found that the primary cooling effect of dozens of rocket launches already coincides with the warming effect of the carbon dioxide released by many millions of commercial flights.

This is not to say that the space industry will override the environmental consequences of flight. Infusing the atmosphere with new particles has complex effects, Ross says. His approximate model found, for example, that rocket launching cooled some locations by 0.5 degrees Celsius while warming the Arctic by more than one degree Celsius. And the simulation did not attempt to include side effects, such as whether the launches would create or kill clouds. More sophisticated modeling could reveal that exhaust particles end up making heating worse, Ross says.

Space launchers are also of concern to some researchers because the rockets expel the exhaust directly into the stratosphere, where the ozone protective layer that blocks harmful ultraviolet light is located.

Most solid rocket engines emit alumina and chlorine gas particles, which promote chemical reactions that break down ozone into molecular oxygen. SpaceX and Blue Origin have moved to liquid fuels, which are usually less harmful, but still have byproducts, including water vapor and nitrogen oxides that can deplete ozone during the years circulating in the upper atmosphere. .

“They’re not harmless,” says Eloise Marais, an atmospheric researcher at University College London. “They have an effect on the atmosphere.”

Marais is working on a forecast of how the current rocket fuel portfolio could thin the ozone layer in the not-too-distant future. He has studied the effects of current launches and those of a speculative scenario in which space tourism is proving popular and reliable enough to withstand a couple of suborbital launches each day and one orbital launch each week.

The calculations need to be verified before publication, Marais says, but preliminary results suggest that while today’s launches have little effect on ozone, an expanding space tourism industry could begin to change. ho.

“It’s a big enough effect that I think we may be concerned about if the industry grows beyond what we’re speculating about,” he says.

The frequency with which companies will launch in the future remains uncertain. Virgin Galactic says it expects to operate 400 flights a year. SpaceX expects Starship to move passengers between major cities in less than an hour, in competition with commercial airlines.

Access to space has revolutionized weather forecasting, communications technology, and the ability of researchers to understand how human activities have altered the Earth’s climate. It has also enabled space-based facilities such as the International Space Station and a fleet of space telescopes to conduct basic transformational research.

In the future, a thriving space industry could unlock practical projects from clean, space-based solar energy to asteroid mining, as well as supporting the search for life in the solar system and other scientific initiatives. .

Researchers like Ross do not want to stop this progress. Rather, they hope to help make this possible by identifying possible environmental issues in advance. The current embryonic space industry is mostly harmless and Ross suggests that an environmental research program could help keep it that way as it matures.

Stratospheric planes could test rocket feathers directly to learn exactly what they spit out, while satellites and ground-based observatories observe the atmosphere for the short-, medium-, and long-term effects of launches. There are also the unknown effects of extinct satellites “burning” and pouring many tons of metal particles into the upper atmosphere. Supercomputers could run comprehensive simulations to determine what levels and types of space activity can be safely performed.

“We’d like to avoid an amazing future,” Ross says. “We would like to say that right now the space industry can move forward in a sustainable way.”