A suborbital flight: the equivalent of a round-the-world trip by car
Suborbital flights allow you to experience weightlessness without being in orbit. “According to the environmental assessment report of the Virgin Galactic SpaceShip Two, we can estimate that the CO2 emission of a complete flight is in the order of 27.2 tonnes. At the rate of six passengers per flight, that’s 4.5 tonnes of CO2 per person. This is equivalent to circling the Earth, alone in an average car, ”explain three French physicists, Roland Lehoucq, Emmanuelle Rio and François Graner, in an analysis published on the site The Conversation. Something to worry the scientific community at a time when the various companies communicate on the hundreds of flights they plan to perform in the coming years.
A flight beyond the ISS: 160 years of car emissions
Proposed by SpaceX, flying further than the International Space Station has a much higher ecological cost. According to the environmental assessment report of the Falcon 9 rocket, the flight emits 1,150 tonnes of CO2. That is, at the rate of four passengers per flight, nearly 290 tonnes of CO2 per person. “In other words, a tourist in orbit is worth 65 suborbital tourists and almost 160 years of emission from a car…”, underline Roland Lehoucq, Emmanuelle Rio and François Graner.
A flight around the moon: the annual “CO2 budget” of several hundred people
The DearMoon project, designed by Japanese billionaire Yusaku Maezawa, plans to take six to eight people to the moon, aboard the Starship spacecraft (second stage of the Super Heavy rocket, the super-heavy and reusable orbital launcher developed by SpaceX ). According to the latest environmental report from this launcher, the assembly produces 3,750 tonnes of CO2 in each flight. “This leads to individual emissions of between 470 and 625 tonnes of CO2. Each person thus grows, in a journey of a few days, the annual “CO2 budget” of hundreds of people, ”note the three physicists. Specifying that all these “invoices” do not take into account the ecological cost of the launch pad and the extraction of the materials necessary for the construction of the rockets.
Roland Lehoucq is a researcher in astrophysics at the Commissariat à l’énergie atomique. Emmanuelle Rio is a research professor in physics at the University of Paris Saclay. François Graner is CNRS research director at Paris Diderot University, Matter and Complex Systems Laboratory. Their full analysis can be read here.
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