During the last two weeks, two of the big players in the space tourism race have made significant steps forward with manned launches. The technology is impressive for sure, but in a world where we are looking for energy and emission reductions in everything we do, including transport and travel, should we be worried about this new industry? Eloise Marais , professor in Physical Geography at UCL , says that with rockets emitting more than 100 times more CO 2 per passenger than flights then maybe we should. The commercial race to get tourists to space is heating up between Virgin Group founder Sir Richard Branson and former Amazon CEO Jeff Bezos. On Sunday 11 July, Branson ascended 80 km to reach the edge of space in his piloted Virgin Galactic VSS Unity spaceplane. Bezos’ autonomous Blue Origin rocket launched and safely returned to Earth on July 20 , coinciding with the anniversary of the Apollo 11 Moon landing. Though Bezos loses to Branson in time, he managed to reach higher altitudes ( about 120 km ). The launch demonstrated his offering to very wealthy tourists: the opportunity to truly reach outer space. Both tour packages will provide passengers with a brief ten-minute frolic in zero gravity and glimpses of Earth from space. Not to be outdone, Elon Musk’s SpaceX will provide four to five days of orbital travel with its Crew Dragon capsule later in 2021. What are the environmental consequences of a space tourism industry likely to be? Bezos boasts his Blue Origin rockets are greener than Branson’s VSS Unity. The Blue Engine 3 (BE-3) launched Bezos, his brother and two guests into space using liquid hydrogen and liquid oxygen propellants. VSS Unity used a hybrid propellant comprised of a solid carbon-based fuel, hydroxyl-terminated polybutadiene (HTPB), and a liquid oxidant, nitrous oxide (laughing gas). The SpaceX Falcon series of reusable rockets will propel the Crew Dragon into orbit using liquid kerosene and liquid oxygen. Burning these propellants provides the energy needed to launch rockets into space while also generating greenhouse gases and air pollutants. Large quantities of water vapour are produced by burning the BE-3 propellant, while combustion of both the VSS Unity and Falcon fuels produces CO₂, soot and some water vapour. The nitrogen-based oxidant used by VSS Unity also generates nitrogen oxides, compounds that contribute to air pollution closer to Earth. Roughly two-thirds of the propellant exhaust is released into the stratosphere (12 km-50 km) and mesosphere (50 km-85 km), where it can persist for at least two to three years. The very high temperatures during launch and re-entry (when the protective heat shields of the returning crafts burn up) also convert stable nitrogen in the air into reactive nitrogen oxides. These gases and particles have many negative effects on the atmosphere. In the stratosphere, nitrogen oxides and chemicals formed from the breakdown of water vapour convert ozone into oxygen, depleting the ozone layer which guards life on Earth against harmful UV radiation. Water vapour also produces stratospheric clouds that provide a surface for this reaction to occur at a faster pace than it otherwise would. Space tourism and climate change Exhaust emissions of CO₂ and soot trap heat in the atmosphere, contributing to global warming. Cooling of the atmosphere can also occur, as clouds formed from the emitted water vapour reflect incoming sunlight back to space. A depleted ozone layer would also absorb less incoming sunlight, and so heat the stratosphere less. Figuring out the overall effect of rocket launches on the atmosphere will require detailed modelling, in order to account for these complex processes and the persistence of these pollutants in the upper atmosphere. Equally important is a clear understanding of how the space tourism industry will develop. Virgin Galactic anticipates it will offer 400 spaceflights each year to the privileged few who can afford them. Blue Origin and SpaceX have yet to announce their plans. But globally, rocket launches wouldn’t need to increase by much from the current 100 or so performed each year to induce harmful effects that are competitive with other sources , like ozone-depleting chlorofluorocarbons (CFCs), and CO₂ from aircraft. During launch, rockets can emit between four and ten times more nitrogen oxides than Drax , the largest thermal power plant in the UK, over the same period. CO₂ emissions for the four or so tourists on a space flight will be between 50 and 100 times more than the one to three tonnes per passenger on a long-haul flight. In order for international regulators to keep up with this nascent industry and control its pollution properly, scientists need a better understanding of the effect these billionaire astronauts will have on our planet’s atmosphere. This article is republished from The Conversation under a Creative Commons license. The original is here .

Should we worry about the climate effects of the space tourism industry?

Žaklīna

Hmm… people complain about normal flights and this is 100 times worse per person so for sure they should be compaining about it. . Much less flights though for some times at least because really how many people can afford this.

Piri

To be honest if I could afford I would do it… anyway now we all need to consider environment impact on all the activities we are doing and choose the most friendly solutions.

Mirmar

Piri To be honest if I could afford I would do it…

Wait for 10 years and it will still be super expensive but possible for 'normal people' and you will be up for more than 10 minutes.

Aiga

Piri To be honest if I could afford I would do it…

Me too, I know it is bad for the environment and a waste of money and that it is not needed and just indulging yourself but I would still do it.

Arvīds

When a few very rich people doing something has much bigger effect than a bigger amount of 'normal' people doing something then of course it is a bad and worrying thing but they are also untouchables and it does not matter how much they pollute or do whatever else.

Piri

Mirmar

This is a possibility 😉 maybe would be enough just flouting in the air with great videos around! 😁

Mirmar

Piri maybe would be enough just flowering in the air with great videos around! 😁

Flowering? Typo? 😆

Piri

Mirmar Flowering? Typo?

Jap!

Skylar

I wonder about this as well. If there is not some more green way to get out of the atmosphere than rockets.

Electric cars be faster and more powerful than petrol engines, Tesla has proved it, there is a lot of research on electric planes, why can't we build an electric spaceship. I know it needs a lot of power to get up there but it would be better to focus on it than have lots of companies competing for the 'old-fashioned' way of flying up to space.

Piri

Skylar I know it needs a lot of power to get up there but it would be better to focus on it than have lots of companies competing for the 'old-fashioned' way of flying up to space

Well I watch many, like super many movies about space and one of the solutions are already kind of suggested. If it would be kind of the shuttles, not the big ones that some bigger planes carry up to the sky on their back and launch them from the air. Theses airplane look like spaceships would be powered by different kind of energy. And the ones which fly them to the air supersonic ones covered by H2 maybe. I don't know why they don't have it yet looks quite simple 😁😁😁

Girl-from-Mars

Piri some bigger planes carry up to the sky on their back and launch them from the air.

I think this is kind of the way that the Virgin Galactic ship works.

The Space X one and Jeff Bezos one are traditional rockets, but the Virgin one is something like you suggested.

Ash

It's definitely not great but I'm not going to lie, one of the things on my bucket list is to go into space before I die. And if it's really possible, I would have to set foot on the moon but that seems a little bit less realistic, unfortunately.

Mushroom-King

Ash And if it's really possible, I would have to set foot on the moon but that seems a little bit less realistic, unfortunately.

How old are you?

Mirmar

Mushroom-King How old are you?

Are you supposed to ask people that?

Ash

Mushroom-King

Early 20s so space travel seems possible (once it becomes a lot cheaper). Setting foot on the moon and it being a viable tourist location seems a little bit out of my reach even at a young age. I think it will take a long time for it to become a thing, especially a cheap thing.

John

@Girl-from-Mars Wouldn't space tourism for you be just like taking a bus home?

Girl-from-Mars

John @Girl-from-Mars Wouldn't space tourism for you be just like taking a bus home?

Haha, kind of 😆

Ash I think it will take a long time for it to become a thing, especially a cheap thing.

Not so sure, humans have been talking about it for a long time and the first bit of space race was really fast progress, then we just stopped almost for a long time. Now that there are more countries and many private companies taking part I think it is going to be even faster again.

Mushroom-King

Ash Early 20s so space travel seems possible (once it becomes a lot cheaper). Setting foot on the moon and it being a viable tourist location seems a little bit out of my reach even at a young age. I think it will take a long time for it to become a thing, especially a cheap thing.

Another 25-30 years and I think that there will be tourism to the moon, so you should be able to get up there.

Ash

True. I think it won't be long before that becomes a reality. The only issue is the price because it will take a long time for the prices to become low enough for most people to afford

Hosted sustainably by S4