The Catastrophic Impact of Rocket Propellant Pollution in Outer Space: SpaceX and the Industry’s Double Standards

As the space industry surges forward with unprecedented technological innovation, there is a growing environmental cost that is largely overlooked—rocket propellant pollution. While many industries face strict environmental regulations, the space sector, particularly commercial companies like SpaceX, continues to operate with little oversight concerning carbon emissions and other environmental impacts. This raises significant questions about the double standards at play, especially given Elon Musk’s public commitment to sustainability through ventures like Tesla and being a self-proclaimed advocate of sustainability on his social media platform X, has remained opaque about SpaceX's carbon footprint, raising serious questions about the double standards at play.Yet, despite Musk's advocacy for clean energy, SpaceX has not provided transparent reports on its carbon footprint, raising concerns about the environmental consequences of its space missions.

The Environmental Cost of Rocket Emissions

Rockets emit a unique blend of greenhouse gases and pollutants that have long-lasting effects on the stratosphere and outer atmosphere. Unlike ground-level emissions, which can be partially absorbed by natural carbon sinks such as forests and oceans, emissions from rockets—particularly black carbon (soot) and CO?—are released into the stratosphere, where they can linger for years. This disrupts the delicate balance of atmospheric chemistry, with potentially catastrophic consequences for climate stability.

Research suggests that black carbon from rocket engines can absorb sunlight in the upper atmosphere, warming the stratosphere while cooling the Earth’s surface below. This effect could contribute to climate feedback loops, amplifying global warming. Additionally, the water vapor produced during rocket launches can lead to the formation of polar stratospheric clouds, which accelerate ozone depletion—a key concern for maintaining the Earth’s protective ozone layer.

CO? emissions from rockets, especially those emitted at higher altitudes, persist in the atmosphere much longer than ground-level emissions, compounding their impact on the greenhouse effect. These emissions are not being absorbed by natural processes, resulting in a disproportionate environmental impact compared to similar emissions from terrestrial sources.

Correcting and Clarifying SpaceX’s Carbon Emissions Breakdown

Let's see the theoritical carbon emissions breakdown for SpaceX's Falcon 9 and Starship rockets in more detail, based on a more accurate understanding of the propellant combustion and emissions calculations:

1. Falcon 9 Carbon Emissions Breakdown

Falcon 9 uses RP-1 (kerosene) and liquid oxygen (LOX) as its propellant.

Propellant mixture ratio (LOX to RP-1): The mixture ratio is about 2.7:1, meaning 2.7 tons of LOX are required for every ton of RP-1 burned.

CO? production: For every ton of RP-1 burned, approximately 3.15 tons of CO? are produced, based on RP-1's molecular composition and its combustion process.

Fuel load per launch: Falcon 9 uses roughly 440 tons of propellant per launch. This includes 340 tons of liquid oxygen and 100 tons of RP-1 (kerosene).

RP-1 contribution: With 100 tons of RP-1, and 3.15 tons of CO? generated per ton of RP-1, the total CO? emissions from RP-1 combustion would be:

100 ? tons?of?RP-1 × 3.15 ? tons?of?CO?/ton?of?RP-1 = 315 ?tons?of?CO?

This means that for each Falcon 9 launch, roughly 315 tons of CO? are emitted into the atmosphere

2. Starship Carbon Emissions Breakdown

Starship uses methane (CH?) and liquid oxygen (LOX) as propellant. While methane is a cleaner-burning fuel compared to RP-1, it still produces CO? when burned.

Propellant mixture ratio (LOX to methane): In Starship's Raptor engine, the mixture ratio is about 3.6:1 (3.6 tons of LOX for every ton of methane burned).

Fuel load per launch: Starship consumes about 1,200 tons of propellant for a full launch. This includes: 900 tons of liquid oxygen 300 tons of liquid methane (CH?).

Methane contribution: For every ton of methane combusted, 2.75 tons of CO? are produced. With 300 tons of methane, the total CO? emissions are:300 ? tons?of?CH? × 2.75 ? tons?of?CO?/ton?of?CH? = 825 ? tons?of?CO?.

Therefore, a Starship launch emits about 825 tons of CO? into the atmosphere from methane combustion alone.

The Space Industry’s Regulatory Gap

The space industry operates within a largely unregulated framework when it comes to environmental standards. Unlike industries such as aviation or automotive, which are subjected to strict controls on carbon emissions, the space sector remains free to set its own standards. Despite the growing environmental concerns about rocket emissions, there are no global mandates that require companies like SpaceX to monitor, report, or reduce their carbon output.

International bodies, such as the United Nations Office for Outer Space Affairs (UNOOSA), have started promoting sustainable space exploration, but their guidelines remain non-binding. Currently, few countries have implemented national regulations that limit rocket emissions or promote the use of green propellants. This creates a significant environmental loophole, allowing commercial space companies to prioritize profitability and technological advancements over environmental responsibility.

The Environmental Cost of the Space Race

The environmental impact of the space industry’s carbon emissions cannot be ignored, especially given the long-term effects of emissions in the stratosphere. While companies like SpaceX are pioneering technological advancements, their contributions to climate change must be addressed with greater transparency and accountability.

As the space race accelerates, it is crucial for governments and international organizations to step in and establish strong regulatory frameworks to ensure that space exploration advances in a sustainable and environmentally responsible manner. Without such oversight, the costs of these technological achievements could prove far more catastrophic than their benefits.

SpaceX has consistently innovated in areas like cost reduction and efficiency, its booster catch mechanism which eliminates the need for landing legs, boosting payload capacity seems catchy. However, the same urgency hasn't been applied to carbon-neutral propulsion despite the environmental necessity. This is partly due to the lack of regulatory pressure on the space industry, which allows companies like SpaceX to prioritize immediate technical needs over long-term sustainability. Elon Musk's push for decentralization and reduced government oversight further enables this, as SpaceX operates without stringent emissions regulations, focusing on economic and technical gains rather than green propulsion innovation.