For a few minutes of pleasure in weightlessness, companies specializing in space tourism risk further accelerating climate change through emissions of CO2, water vapor or soot.
Unnecessary pollution? This Thursday, Blue Origin launched its sixth space tourism mission. A flight observed by many amateurs, but also very criticized for the pollution it generates. Many fear that the emissions associated with this nascent industry are too high.
In reality, it is very difficult to know with certainty the ecological cost of a flight, since the data is kept secret by the companies concerned. Blue Origin has also tried to defend itself against this.
“The New Shepard rocket engine runs on clean liquid oxygen and hydrogen. During flight, combustion produces only water vapor with no carbon emissions,” a spokesperson told Reuters. magazine Time.
Only, as recalled by Time, water vapor is a greenhouse gas. According to NASA, it is even the largest on Earth, responsible for more than half of the greenhouse effects suffered by the planet.
SpaceX circumvents the problem?
Concerning Virgin Galactic, data have been made public thanks to a survey by the American Federal Aviation Administration dating from 2012. In this text, the American agency reveals that SpaceShipTwo flights emit 27.17 tons of CO2, which corresponds to nearly 140,000 km by car according to ADEME’s CO2 converter.
Little information circulates on the ecological weight of SpaceX. To prevent criticism, Elon Musk however assured last December that he intended to recover CO2 present in the atmosphere to transform it into fuel for his rockets.
However, CO2 and water vapor might not be the most serious pollution in space tourism. Indeed, space flights produce a lot of soot according to a study published in Earth’s Future in June. And the fact that it produces much less than conventional air traffic does not reduce the problem depending on the height at which this fine particle is rejected.
Soot “directly injected into the upper atmosphere” with rockets has an impact on climate change “500 times greater than all other sources of soot”, such as airliners, write the authors of the study.
Concerns are likely to grow over time as space tourism companies plan to exponentially increase the number of flights. In 2021, Virgin Galactic said it wanted to reach 3 tourist flights per month in 2023, a rate that could be followed by competing companies.