As the commercial race in space enters the fast lane, please do not disregard the potential impact on our climate!
Each passenger aboard a missile emits 100 times more carbon dioxide than a airplane -- imagine the industry
Sir Richard Branson talks to Agence France-Presse before the official unveiling of Virgin Galactic's spaceshipTwo, the world's first commercial manned spacecraft, at the Mojave Spaceport in California December 7, 2009.
The commercial race to send passengers into space is heating up between Virgin Group founder Sir Richard Branson and former Amazon CEO Jeff Bezos 39bet-xsmb-xổ số tây ninh-xổ số binh phước-xổ số binh dương-xổ số đồng nai. On Sunday, July 11, Branson ascended 80 kilometers to the edge of space aboard his Virgin Galactic VSS Unity spaceship. Bezos blasted off on a self-guided Blue Origin rocket on July 20, the anniversary of the Apollo 11 moon landing.
Bezos did launch later than Branson, but he managed to achieve a higher altitude (about 120km). The launch demonstrated his ability to provide a service to the super-rich: literally taking passengers into outer space. His service has two packages, both of which will offer passengers ten minutes of zero-gravity activity and a glimpse of Earth from outer space. Not to be outdone, Elon Musk's SpaceX said it would offer passengers four to five days of orbital travel in its crewed Dragon spaceship later in 2021.
And what might be the environmental impact of the increase of space tourism? Mr Bezos boasts that his Blue Origin rocket is greener than Mr Branson's VSS Unity. The Blue Engine 3 (BE-3) will utilize liquid hydrogen and oxygen propellants to lift Bezos, his brother and two other passengers into space. VSS Unity utilizes a hybrid propellant consisting of a solid carbon-based fuel, hydroxyl-terminated polybutadiene (HTPB), a liquid oxidizer, and nitrous oxide (commonly known as laughing gas).
The burning of these propellants provides the missile with the energy it requires to climb into space, but it also generates a lot of greenhouse gases and air pollutants. The combustion of the BE-3 propellant generates a lot of water vapor, while the combustion of the VSS Unity and Falcon rocket fuel produces carbon dioxide, soot, and some water vapor. The nitrogen-based oxidants used in VSS Unity also generate nitrogen oxides, compounds that further produce air pollutants closer to Earth.
About two-thirds of the propellant exhaust is released into the stratosphere (12 km -50 km) and mesosphere (50 km -85 km) and persists for at least two to three years. In addition, during missile launch and re-entry, the ultra-high temperatures also convert stable nitrogen in the air into reactive nitrogen oxides.
The exhaust gas and particulate matter produced by these missiles can cause numerous negative effects on the atmosphere. In the stratosphere, nitrogen oxides and chemicals formed by the decomposition of water vapor in the atmosphere due to high temperatures convert ozone into oxygen, depleting the ozone layer that protects life on Earth from damaging ultraviolet radiation. The massive amount of water vapor generated during the launch also generates stratospheric clouds in the sky, speeding up the rate of these reactions.
Space travel and climate change
Emissions of carbon dioxide and soot trap heat in the atmosphere, causing global warming. Stratospheric clouds formed by emitted water vapor reflect incoming sunlight back into space, enhancing the cooling effect of the atmosphere. And the decreased ozone layer will absorb less sunlight, which will decrease the heating effect of the stratosphere.
Understanding the entire impact of a missile launch on the atmosphere involves detailed physical modeling of these complex processes and how long the resulting pollutants persist in the upper atmosphere. And it will help to understand how the space tourism industry will evolve in the future.
Virgin Galactic estimates it will have the capacity to provide 400 space flights a year for a handful of capable people. Blue Origin and SpaceX have yet to reveal their proposals. But on a global scale, missile launches would not require to rise much from the current 100 or so a year to have approximately the same negative impact as other sources, such as ozone-depleting hydrochlorofluorocarbons (CFCs) and carbon dioxide from jets.
A SpaceX Falcon 9 rocket launches a GPS ⅲ SV05 satellite for the U.S. Air Force from Space Launch Complex 40 at Cape Canaveral Air Force Station in Cape Canaveral, Florida, June 17, 2021.
During launch, the missile emits four to ten times more nitrogen oxide than Drax, Britain's giant coal-fired power plant, does during the same period. On a space flight, supporting four or so visitors in space would emit 50 to 100 times more carbon dioxide than one to three tons per passenger on a long flight.
In order for international regulators to keep pace with this new industry and correctly regulate pollution from missile launches, researchers need to better grasp how the travel plans of these billionaire astronauts affect our atmosphere.