The carbon footprint of space travel was not a big issue in previous years because of the minimal number of rocket launches and the fact that space travel was limited to a select few government agencies around the world.
However, that concern has grown because of how much the industry has grown, and more rockets are expected to launch in the future.
This guide outlines those concerns about the carbon footprint of space travel, and ways to reduce them.
Living In Space: Potential New Reality
Significant damage has been recorded to sites where rockets have been launched, such as poisoning the soil for a long time after the launch.
Rockets have combustion-driven propulsion, which means that launching the rocket releases a huge amount of soot, black carbon, and other emissions.
Unsymmetrical dimethylhydrazine, fuel for most rockets, is carcinogenic to human beings. It has also caused irreparable damage to the areas surrounding any spaceport that the rockets have launched.1
Even with so much ecological damage and an extremely high carbon footprint, launch, flight, and living in space are integral to the growth and development of the 21st-century world.
Therefore, the best way to approach the issue is by finding solutions to minimize space travel’s carbon footprint and develop better products for the industry.
The Environmental Impact of Emissions From Space Launches: Environmental Impact of Rocket Launches
Rocket emissions have a severe impact on the ozone layer, the atmosphere, and temperatures. However, the degree of impact largely depends on the type of engine and propellant that each rocket uses. That means while some are poison to the environment and any living thing on earth, some are green and safe to use.
There is very limited data and research on the environmental impact of some of these propellants and engines. Extreme caution should be applied when dealing with any of them. Below is an analysis of space travel’s impact on the environment based on the available data.
UDMH is a rocket fuel nicknamed ‘Devils venom’ by Soviet scientists because of the damage it left behind in Kazakh. Baikonur Cosmodrome, one of the oldest spaceports in Kazakh, Russia, has seen hundreds of Proton rockets launched as early as 1965.
Due to the spills of the rocket fuel as the rockets fell in 1st and 2nd stages, the area around the spaceport was soaked in the poison. The soil in these lands has suffered the effects of the UDMH spills for decades.
Rocket fuel is slowly being phased out of the rocket fuel industry, but some parts of the world, like China, are still using it for their 2nd and 4th generation Long-March rockets. In Western countries, however, the propellant used has been reduced to satellite propulsion in the upper stages where there is no contact with the atmosphere.2
Solid Rocket Motors
Solid rocket motors are used for rocket liftoffs, particularly NASA space shuttles.7 When space shuttles launch with SRMs, the cloud generated during the launch has some reactive chemicals that affect the water and soil quality of neighboring areas.
According to a study on the effects of space shuttle launches on terrestrial life, dead fish were discovered in the waterbodies near the launch site.8 Further experiments proved that the exhaust fumes from the launch turn the water into a mild acid that kills the fish.
Aluminum oxide particles from space shuttle launches also trigger temperature changes, which could affect the amount of heat that the earth gets. SRM boosters are used in heavy-lift rockets, and even though space shuttles are no longer in use, rockets like Ariane 5 are still using them.
Hybrid Rocket Engines
Hybrid rocket engines are popular with the SpaceShipTwo space planes operated by Virgin Galactic. While they are safe and very simple to operate, they have environmental side effects that emanate from the soot produced during takeoff.
Although the black carbon particles from these engines are lightweight and quite small, they settle in the higher levels of the atmosphere, and decades later, they start affecting heat absorption. That accumulation, therefore, threatens the earth’s atmosphere prosperity.
Rocket propellant-1, denoted as RP-1, is a popular rocket fuel with the energy to lift rockets off the ground without the need for solid rocket boosters. It is an equivalent of aviation fuel kerosine and has been used to power rockets like Delta, Saturn, and Falcon 9.
Some of the reasons why this rocket fuel is popular are its stability at room temperature and non-explosive nature. Being a more refined form of kerosine, RP-1 cheaper, safer, and more reliable than most other rocket fuels.
However, it also produces soot, meaning that using the fuel to launch rockets contributes to carbon emissions into the atmosphere. While that contributes to the huge pool of greenhouse gasses emitted into the atmosphere by industries, it makes up a very small percentage.
Black carbon emission from rockets is not enough to raise the alarm, but eliminating the emissions could contribute to the bigger goal of managing climate change. Other industries, like aviation, contribute much more carbon emissions than rockets.
Liquid Oxygen/Liquid Hydrogen
Liquid oxygen/Liquid hydrogen is the ideal rocket fuel when it comes to environmental consciousness. It has zero effects on the environment as it is purely made from water vapor.
However, it has disadvantages that disqualify it from the best rocket fuel title. One of its misgivings is that it is not powerful enough to lift huge rockets off the ground. For that reason, huge rockets like Ariane 5 and SLS have to use solid rocket boosters to launch.
Liquid oxygen/Liquid hydrogen as the only propellant would work well in small rockets like New Shepard. These rockets are suborbital and do not require too much energy to overcome gravity. The other downside of LOx/LH2 is that it is highly explosive. It requires extremely high caution to handle.
The spaceflight industry keeps looking at better ways of balancing the effectiveness and environmental conservation of rocket fuels. An upcoming technology of methane-based propellant looks promising in all aspects.
It has fewer environmental effects than solid rocket motors and more energy than LOx/LH2. That comes from its high burning efficiency, meaning that there is almost no residue. Methane is also expected to produce a smaller amount of soot compared to kerosene.
The only worry for this new rocket propellant is that its leakage could accelerate climate change. Since it is transported through pipes and in the form of gas, it could leak and cause 80 times more damage than CO2 to the environment. However, some of the existing rockets, like Starship, are already using methane in their engines.
In an attempt to find green fuels that rockets can use to launch, companies like Orbex and Skyrora have been experimenting with biofuels.10 According to Orbex, bio-propane could be a better solution compared to RP-1. With about 86% fewer emissions, Orbex says that bio-propane could significantly reduce the carbon footprint of space travel.3
Similarly, Skyrora has experimented with Ecosene and discovered that it could reduce emissions by about 40%. Ecosene is made from non-recyclable plastics, making it an excellent environmentally conscious rocket propellant.
However, all these products are in their early stages of testing, meaning that more research and experiments must be done before any conclusive decision is made.
Environmental Impact of Space Travel: Carbon Footprint of Space Travel
People have not been paying attention to the environmental impacts of space travel before, and for a good reason. The industry was small and government-focused, making it insignificant to other industries’ emissions.
Today, that has changed in that launches have significantly increased, and private companies have come up in the industry. There is more reason now to understand its contribution to global warming and devise better methods and products to reduce emissions. What is the carbon footprint of a space launch?
Carbon Footprint of a Space Launch: Carbon Footprint of Flight
|ISRO’s GSLV, NASA’s Space Shuttle
|Hydroxyl-terminated polybutadiene (HTPB), Solid aluminum fuel, Ammonium perchlorate (NH4CIO4) Oxidizer
|Carbon dioxide (CO2), Hydrochloric acid (HCl), Alumina (Al2O3), Water vapor (H2O), Black carbon (BC), Nitrogen oxides (NOx)
|Russia’s Proton (1, 2, 3), ESA’s Ariadne 1/2/3/4 (1, 2), China’s Long March 1/2/3/4 (1, 2)
|Unsymmetrical dimethylhydrazine (UDMH), Dinitrogen tetroxide (N2O4) Fuel, Hydrazine (N2H4)
|Nitrogen (N2), Carbon dioxide (CO2), Water vapor (H2O), Black carbon (BC), Nitrogen oxides (NOx)
|ESA’s Ariadne 1/2/3/4 (3), NASA’s Space Shuttle (1), ISRO’s GSLV (3)
|Liquid hydrogen, Liquid oxygen
|Hydroxyl (OH), Water vapor (H2O), Nitrogen oxides (NOx), Hydrogen (H2)
|Russia’s Soyuz (0, 1, 2), Space X’s Falcon 9 (1, 2)
|Kerosene, Liquid oxygen
|Black carbon (BC), Water vapor (H2O), Carbon dioxide (CO2), Hydroxyl (OH), Carbon monoxide (CO), Nitrogen oxides (NOx)
The Carbon Footprint of Space Travel in Different Spaceflight Companies
The type of emissions and the amount depend on a few factors. One of them is the fuel that the rocket uses to launch. Different spaceflight companies use different propellants, as seen in the table above.
Each propellant has different emissions, which determine how big or small the carbon footprint of their spaceships is.The size of the rocket also matters when calculating its carbon footprint of a rocket.9 Smaller rockets will require less energy to launch, which means that the fuel used will also be minimal.
In some cases, spaceflight companies can even use purely green propellants like LOx/LH2 to power the rockets, making it possible to have a very small carbon footprint, if any.
Below is a breakdown of the carbon footprint of some of the most popular spaceflight companies and their spaceships.
Carbon Footprint of Virgin Galactic Flight: Virgin Galactic CO2 Emissions
Virgin Galactic is a space lift company that deals with commercial spacecraft to ferry space tourists. The first passenger ship is expected to launch in the Spring of 2023 for suborbital spaceflight.
Robert Branson, the founder, says that the company aims to launch at least 3 spacecraft per month in 2023. With an increased number of rockets launched every month, black carbon emissions will double or even triple.
Virgin Galactic spacecraft use hybrid rocket engines, which burn like a candle and, therefore, produce soot. The emission of black carbon particles into the higher layers of the atmosphere will have bad environmental effects with time.
SpaceX Environmental Impact – SpaceX Rocket Pollution: Carbon Footprint of Space Travel
Like all other spaceflight companies, SpaceX plans to increase its spacecraft launches in the coming years.
These companies are advocating for space tourism, which means that the industry will grow rapidly soon.
While that is good for tourists and development, it will cause immense damage to the ozone layer. These rockets use fuels that produce carbon, and the more the flights, the more emissions.
Below is a breakdown of the expected carbon emissions from the Elon Musks spacecraft.
SpaceX Carbon Footprint (SpaceX Starship Emissions and Falcon 9 Emissions)
SpaceX rockets use kerosene to power their space flight. While kerosene is powerful and can power the rocket successfully to space, it produces soot that contains black carbon particles.
It would not have much effect if the rocket launches were as minimal as a few years back.
However, the industry has grown, and SpaceX is determined to start commercializing the rockets for space travel. If the cost of a trip to the moon becomes affordable, there could be as many as a thousand rockets launched every year.
Here is a small calculation of the expected carbon footprint based on the amount of fuel used to power the rockets.
The Falcon 9 B uses 29,600 gallons, equivalent to 112,184 Kg of kerosene per launch.4
For each kilogram of kerosene burned, 3 Kg of CO2 goes into the air.5
112,184 Kg x 3 Kg CO2 = 336,552 Kg
That means 336,552 kilograms of CO2 go into the atmosphere every time Falcon 9 is launched. While that is just an approximation, it paints a picture of what multiple launches would do to the environment.
Rocket Emissions vs Car – Rocket Pollution vs Cars
Carbon Footprint of Flying vs Driving
You can get an international flying carbon offset to help erase those emissions.
Can We Get to Space Without Huge Carbon Emissions?
There are no regulations to monitor the carbon emissions of space travel. However, the new companies coming up in the industry are taking it upon themselves to initiate green operations.
With their plan to increase the number of rockets that launch every year, they are also cautious not to damage the ozone layer in the process.
SpaceX is one of the companies focused on looking for fuel alternatives to avoid the severe environmental consequences of space travel. As the industry grows, new solutions to rockets’ environmental impact will come up and help save the planet.
Space travel is revolutionary and could give humans a chance to visit other planets and discover the world. However, that will come at a cost.
With the private sector joining the spacecraft industry, more possibilities and innovations are likely to happen.
That includes finding solutions to the adverse environmental effects of space travel. Most companies in the industry are already taking the initiative to find better rocket propellants and avoid interfering with other lives when launching.
With a combined effort, the industry can reduce the carbon footprint of space travel eventually.
Frequently Asked Questions About Carbon Footprint of Space Travel
Why Does It Rain After a Rocket Launch?
The rocket engines run on liquid oxygen and liquid hydrogen propellants. When it launches, the combustion of the propellants forms large clouds of steam that go beyond 6,000 °F. That steam then rises and cools in the air, becoming a cloud that can make it rain in the nearby areas.
How Much Is 300 Tons of Carbon Dioxide in Kg?
One ton = 907.2 kg so, 300 tons = 272,160 kgs
Is There a Carbon Footprint Flight Calculator?
Yes. You can find carbon footprint calculators on different websites online.
How Much Co2 Does a Spacex Rocket Produce?
It produces about 336,552 Kg per flight.
Are Rocket Launches Bad for the Environment?
The damage is insignificant when only a few rockets launch yearly, but when that number increases, the damage is huge and can be detrimental over time.
How Much Pollution Does a Space Shuttle Produce?
A space shuttle uses solid rocket motors to launch, producing exhaust fumes that could affect the water bodies and alter the PH. They also produce aluminum oxide particles that could cause temperature changes.
Do Rockets Damage the Ozone Layer?
Not instantly, but an accumulation of the particles emitted from the rockets could damage the ozone layer.
How Much Carbon Does a Rocket Launch Produce?
About 336,552 Kg of carbon per launch.
How Can Spaceflight Companies Minimize the Carbon Footprint of Space Travel?
By using green propellants.
How Much Pollution Do Rockets Produce?
A considerable amount when the number of rockets launched increases.
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4Zaremba, H. (2017, August 8). How Much Fuel Does It Take To Get To The Moon? HuffPost. Retrieved October 27, 2022, from <https://www.huffpost.com/entry/how-much-fuel-does-it-take-to-get-to-the-moon_b_598a35b5e4b030f0e267c83d>
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7Purdue. (2022). Solid Rocket Propulsion. Purdue Engineering. Retrieved November 7, 2022, from <https://engineering.purdue.edu/~propulsi/propulsion/rockets/solids.html>
8Hawkins, W. E., Overstreet, R. M., & Provancha, M. A. (1984, December). Effects of Space Shuttle Exhaust Plumes on Gills of Some Estuarine Fishes: A Light and Electron Microscopic Study. UNL Digital Commons. Retrieved November 7, 2022, from <https://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1524&context=parasitologyfacpubs>
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