Environment and climate: what space tourism costs the planet


This article was originally through The Conversation under a Creative Commons license on September 24, 2020. It was updated after Richard Branson’s space flight and before Jeff Bezos’s. The authors of the article are Roland Lehoucq, researcher in astrophysics at the French Atomic Energy and Alternative Energies Commission (CEA), Emmanuelle Rio, teacher-researcher in physics at the University of Paris-Saclay and François Graner, biophysicist and director CNRS research at the University of Paris.


While Richard Branson has just made a round trip to touch space with his finger, Jeff Bezos in turn flies to the confines of the Earth’s atmosphere, further expanding the list of space tourists.

In September 2018, Japanese billionaire Yusaku Maezawa bought the system’s services from Elon Musk Starship of his company SpaceX for a trip around the moon, from 2023. We do not know the amount of the bill, but it is probably colossal.

Between 2001 and 2009, eight tickets to board the Russian spacecraft with the astronauts Soyuz have been sold. Direction the International Space Station, the famous “ISS”. A round trip between 20 and 35 million dollars per person – which represents the daily budget of fifteen million humans living in the international poverty line.

Beyond the obscenity of an operation aimed at satisfying the dream of a single individual, these excursions anchor the idea that space is a commodity. They also consume material and energy and have environmental consequences which would increase considerably if this space tourism were to be the subject of wider trade.

Let us therefore try to quantify the consequences by distinguishing the flights which pollute a little, but very numerous, the flights which pollute moderately and which are quite numerous, and the flights which pollute extremely, but which are few in number.

Test weightlessness in a parabolic flight

For 6,000 euros, you can already treat yourself to a flight in a plane chaining a succession of parables, allowing you to feel the reduced gravity of Mars or the Moon, and especially to float twelve times in weightlessness for about twenty seconds.

Passengers of the Airbus A330 & nbsp; Zero-G, & nbsp; on March 15, 2013, in a phase of weightlessness.  (MEHDI FEDOUACH / AFP)

This is how the company Novespace embarked 1,856 passengers on 217 flights each lasting about two and a half hours, which is the duration (and the pollution) of a Paris-Warsaw flight. Insofar as the number of passengers was limited, the total pollution of this luxury merry-go-round remained modest compared to 915 million tonnes of CO₂ emitted in 2019 by the 4.5 billion passengers on all commercial flights (more than 100,000 per day on average).

See the curvature of the Earth in suborbital flight

Going into space requires climbing much higher than planes, beyond 100 km altitude. It is the object of a so-called “surborbital” flight, because the speed of the vessel remains insufficient to place it in orbit. His ballistic flight allows you to experience weightlessness for several minutes while admiring the beauty of the curvature of the Earth. Advertised at $ 250,000, this is expensive visual proof of the roundness of our planet, but temporarily relieves you of the proximity of the popular classes.

The Virgin Galactic company, owned by billionaire Richard Branson, announced in July 2020 that it already had sold 600 tickets for his SpaceShip Two, and the company is building two other similar vessels. This potentially means hundreds of scheduled flights, since 9,000 customers have already expressed their interest. Billionaire Jeff Bezos’ Blue Origin company is also in the running with its reusable rocket New Shepard, also designed to launch a capsule carrying six space tourists on a suborbital trajectory culminating at about 100 kilometers.

The Virgin Galactic SpaceShipTwo, July 11, 2021 in New Mexico (United States).  (PATRICK T. FALLON / AFP)

According to the environmental assessment report SpaceShip Two, we can estimate that the emission of CO2 of a complete flight is of the order of 27.2 tons. At the rate of 6 passengers per flight, that makes 4.5 tonnes of CO2 per passenger. This is equivalent to circling the earth, alone in a average car. For a few minutes of weightlessness, that’s more than twice the individual emission annual (“CO budget2“) allowing, according to the IPCC, meet the + 2 ° C objective of the Paris Agreement. In other words, each passenger will blithely trample on this objective and will arrogate to themselves the right to broadcast in place of other humans.

The hybrid propulsion of SpaceShip Two does not only produce CO2. The ship also spits soot, resulting from the incomplete combustion of a mixture of nitrous oxide (N2O) liquid and a solid derivative of polybutadiene hydroxytelechelic. A 2010 scientific article estimated that 1,000 suborbital flights per year would produce in the order of 600 tons soot, which, by remaining suspended in the stratosphere for about ten years at an altitude of 30 to 50 kilometers, would contribute to modifying the climate on the scale of the entire planet – even if all the shots started from a same place. By comparison, civil aviation would appear almost clean: it emits more soot in total, 7,200 tons per year, but at altitudes of the order of 10 kilometers, which reduces their suspension time and allows them to be washed out by rains.

Visit the International Space Station

Let’s continue by moving up the ladder. Since 2009 and the commissioning of the European and Japanese scientific modules, the crew of the expeditions to the ISS has grown to six astronauts from the countries that funded it. This obligation left no room for a private passenger and the Russian space agency has suspended tourist flights.

But flights to the ISS for ultrariches will resume at the initiative of the company Space Adventures (which also sells weightless flights). After years of absence, the United States has indeed regained its ability to send humans into space following the successful qualification flight of the capsule Crew Dragon launched by SpaceX last May. Space Adventures took the opportunity to recover two free seats on Russian Soyuz flights, while announcing a partnership with the company SpaceX.

The price of such a flight will be around $ 100 million. At such a price, to realize the dream ofIcarus (beware, it ends badly), you should probably be part of the 11,000 people with more than $ 250 million or maybe win a reality tv lot. It then remains to pass the physical fitness tests for space flight, in particular to ensure that the passenger’s body will be able to withstand the acceleration of take-off.

The 119 tonnes of refined kerosene used by the first stage of the Falcon 9 rocket produce, during their controlled combustion, an energy comparable to that released by the recent explosion which devastated the port of Beirut and its surroundings: the equivalent of 1,220 tonnes of TNT.

According to the environmental assessment report Falcon 9, the complete flight, with capsule recovery manned thanks to specialized ships and a helicopter, will emit 1,150 tonnes of CO2, the equivalent of 638 years of emissions from an average car traveling 15,000 km per year. Much more than a crossover of vacationers on the highway! At the rate of four passengers per flight, that makes nearly 290 tonnes of CO2 per passenger. In other words, a tourist in orbit is worth 65 suborbital tourists and almost 160 years of emission from a car …

Around the moon

A flight around the Moon like the one Maezawa is planning is of course still reserved for billionaires, who already number more than 2,000 and whose number is constantly growing. The ship Starship, on board which the trip will take place, is the second stage of the rocket Super Heavy, the super-heavy and reusable orbital launcher developed by SpaceX. The latest environmental report from this launcher indicates that the assembly Starship/Super Heavy produces the trifle of 3,750 tonnes of CO2 on every flight. The DearMoon project planning to take on 6 to 8 people, this leads to individual emissions of between 470 and 625 tonnes of CO2. Each person thus grows in a trip of a few days the “CO budget2“annual of several hundred people. But this is still lower than 1,630 tonnes of CO2 issued annually by Bill Gates for his private jet trips …

We save you, probably wrongly, the cost in CO2 the construction of firing points. It’s concrete, and also a lot of footprint in terms of area occupied. If at Roissy, the airport occupies about a third of the area of ​​intramural Paris (32 km2), it does so for more than 470,000 aircraft movements per year and nearly 70 million passengers. By comparison, suborbital flights scheduled by Virgin Galactic must depart from Spaceport America in New Mexico, whose area of ​​73 km2 at most only 1000 flights per year.

We also spare you the environmental consequences of extracting, transporting and processing high quality materials,steel or thealuminum for example, necessary to manufacture the total mass of rockets, and the whole of which will not be completely recovered.

The richest 1% are responsible for twice as many emissions as the poorest half of humanity. After their private yachts and their business planes, the space whims of these (ultra) rich maintain the illusion of omnipotence at the origin of the serious disturbances of the terrestrial biosphere. If economies of scale due to technical improvements made space tourism accessible to even the upper classes, these inequalities would be further amplified, adding to the degradation caused by our societies in general and by mass tourism in particular.


Authors: Roland Lehoucq, researcher in astrophysics at the French Atomic Energy and Alternative Energies Commission (CEA), Emmanuelle Rio, teacher-researcher in physics at the University of Paris-Saclay and François Graner, biophysicist and CNRS research director at the University of Paris.

This article was originally through The Conversation under a Creative Commons license on September 24, 2020. It was updated after Richard Branson’s space flight and before Jeff Bezos’s.



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