Blue Origin, Virgin Galactic… Beyond the technological prowess, sending tourists into space also raises environmental issues, especially in the current context. Regarding the flight that interests us today, to what extent will the Blue Origin launcher pollute the planet?
The first commercial flight of the New Shepard launcher, developed by Jeff Bezos' company Blue Origin, is scheduled for this Tuesday, July 20, 2021 at 3 p.m. (French time). This flight will take place nine days after that of Sir Richard Branson and his crew aboard the VSS Unity, offered by the company Virgin Galactic.
Over the past few weeks, many people have been concerned about the carbon footprint of these flights, and more generally of this fledgling industry. Naturally, we still lack perspective to be able to assess it. Initially, this will have to be done on a case-by-case basis.
Regarding today's flight, how much pollution will Jeff Bezos and his crew generate to soar into space?
It should be noted that Blue Origin's New Shepard rocket should be one of the "cleanest" launchers on the market . It combines liquid hydrogen and liquid oxygen (LOX) in its engine to generate thrust, which means that "the main emissions will be water and some minor combustion products, and virtually no CO2 “Summarizes Darin Toohey, atmospheric scientist at the University of Colorado at Boulder, to Livescience.
“The presence of water in launcher exhaust could also increase cloud density in the atmosphere, including the iridescent "pearl" clouds often seen at sunset after a launch “, adds the researcher.
Let us remember, however, that water vapor is a more powerful greenhouse gas than CO2 and the longer this vapor will remain in the upper layers of the atmosphere (mesosphere and ionosphere), the more it will warm the Earth. Blue Origin's New Shepard will however shut down its engine relatively early in the flight. So there shouldn't be any problem there. Moreover, the number of rocket launches being today still very low, these data are not of concern in climate models.
In the future, however, the pace of launches should normally accelerate, with several players vying for a very juicy market. Therefore, more studies should be conducted on the potential impact of such flights in the future.
More generally, the CO2 pollution generated by spaceflight is still negligible. These shots were indeed approximately 0.0000059% of all CO2 emissions in 2018, according to Everyday Astronaut, up from about 2.4% global CO2 emissions for the airline industry.
For the researcher, the main concern inherent in these rocket flights is small particles such as soot and aluminum oxides. “These can have a disproportionate impact on the atmosphere. A very small amount can make a big difference ". The New Shephard's engine doesn't produce many of these particles, but others could potentially produce a lot of them in the future.
To give you an idea, a study published in 2010 on the effects of soot injected into the atmosphere from one thousand private suborbital flights per year at the time suggested that they could raise temperatures above the poles by 1°C and reduce polar sea ice levels by 5% to 15% .
