Nasa's Air Pollution: What's The True Cost?

Rocket launches are a major contributor to air pollution, and NASA is no exception. The space agency's new Space Launch System moon rocket, which first launched in November 2022, is particularly notorious for its environmental impact. While the number of rocket launches is relatively low compared to airplane flights, the type of fuel and the amount of pollution released during each launch significantly affect the atmosphere and ozone layer. NASA's rockets, like those of other space organizations, use various fuels, including liquid oxygen, kerosene, and methane, which produce pollutants such as soot, carbon dioxide, and chlorine. The pollution from these launches can linger in the stratosphere for years, contributing to climate change and damaging the ozone layer, exposing our planet to harmful ultraviolet radiation.

Rocket launches produce less pollution than the aviation industry

Rocket launches are an integral part of the 21st century, but they also contribute to air pollution. The fuel used by rockets determines the kind of air pollutants emitted during launch. For instance, the SpaceX Falcon 9 rocket uses a fuel mixture of liquid oxygen and kerosene, which produces black soot that is injected directly into the stratosphere. Kerosene-fuelled rockets like the Falcon 9, Falcon Heavy, Electron, and Soyuz are responsible for most rocket soot. However, methane-fuelled rockets produce less soot, and Blue Origin's New Shepard rocket, which burns liquid oxygen and hydrogen, only produces water vapour as exhaust.

Despite the pollution produced by rockets, rocket launches produce less pollution than the aviation industry. The aviation industry burns 100 times more fuel annually than all globally launched rockets combined. Additionally, airplanes fly in the troposphere at about 11 km (6.6 mi) above the ground, while most rockets release their emissions in the stratosphere, ranging from 12 km (7.5 mi) to 50 km (31 mi) above the Earth. As a result, soot from airplane emissions precipitates more quickly than stratospheric soot, which remains in the atmosphere for a longer period. Furthermore, the percentage of fossil fuels burned by the space industry is only about 1% of that burned by conventional aviation.

While rocket launches produce less pollution than the aviation industry, the increasing rate of rocket launches and the growth of the space tourism industry are cause for concern. Launch rates have tripled in recent decades, with a record-setting 180 launches to orbit in 2022. As the number of launches increases, the impact on the atmosphere will become more significant. Additionally, space tourism, which is being pursued by companies like Virgin Group, Amazon, and Tesla, will come at a significant environmental cost. Rockets require large amounts of propellants, and the emissions from these propellants contribute to ozone depletion and climate change.

To address the environmental impact of rocket launches, some companies are exploring the use of sustainable rocket fuels. For example, Orbex's rocket uses bio-propane, a renewable biofuel, which is expected to have 90% fewer emissions than an RP-1-fuelled launch. Virgin Orbit is also investigating the use of sustainable fuels, and NASA is exploring new ways of launching satellites, such as horizontally or using a slingshot mechanism. These efforts to reduce the atmospheric impact of rocket launches are crucial as the industry continues to grow and evolve.

NASA's Space Launch System moon rocket is highly polluting

NASA's Space Launch System (SLS) moon rocket, which first launched in November 2022, is a highly polluting machine. The rocket is part of the Artemis program, which aims to reestablish a human presence on the Moon and eventually facilitate human missions to Mars. While rocket launches are relatively small contributors to overall atmospheric pollutants compared to the aviation industry, they still produce significant amounts of pollution.

The Space Launch System's solid rocket boosters produce the ozone-damaging pollutant chlorine, which contributes to climate change and damages the ozone layer. This exposure to dangerous ultraviolet (UV) radiation can have harmful effects on both the environment and human health. According to the World Health Organization and the Institute for World Health Metrics and Evaluation, air pollution is one of the leading risk factors for premature deaths and chronic diseases worldwide.

In addition to the environmental concerns, the NOAA report highlights that a single passenger aboard a rocket is responsible for 100 times more climate-changing pollution than a passenger aboard an airplane. The soot created by burning kerosene in rocket engines is injected directly into the stratosphere, where it can linger for up to five years, absorbing heat and further contributing to climate change. The change in temperatures caused by rocket pollution can also have broader impacts, such as slowing subtropical jet streams and worsening summer monsoons in regions like Africa and India.

While NASA's Space Launch System moon rocket is highly polluting, it is important to note that the space industry is constantly working to improve the cleanliness of their technologies. For example, SpaceX's Starship spacecraft uses methane instead of kerosene, burning cleaner and producing less black soot. Additionally, Blue Origin's New Shepard rocket burns liquid oxygen and liquid hydrogen, resulting in water vapor as its only exhaust. However, water vapor in the upper atmosphere can still trap and retain heat, contributing to the greenhouse effect.

SpaceX's Starship spacecraft uses polluting methane fuel

While rocket launches are small contributors to overall atmospheric pollutants, the aviation industry burns 100 times more fuel each year than all the rockets launched globally combined. However, the soot from burnt fuel in the aviation industry precipitates much quicker from the troposphere, about 11 km or 6.6 miles above the ground, compared to the soot from rockets, which sticks around much longer in the stratosphere.

SpaceX has faced criticism for the environmental impact of its Starship spacecraft. One source claims that the 33-engine Starship is one of the dirtiest rockets ever built due to its size. Another source states that a single Starship launch produces 76,000 metric tons of carbon dioxide equivalent, which is 2.72 times more than the emissions produced by a single SpaceX Falcon 9 launch. However, it is important to note that the Falcon 9 rocket uses kerosene, which creates black soot that is injected directly into the stratosphere, contributing to climate change and damaging the ozone layer.

Despite the environmental concerns, some argue that the SpaceX Starship is one of the most environmentally friendly rockets available. The Starship eliminates solid boosters and heavy hydrocarbon fuels, and all hardware is recovered for reuse instead of being disposed of after a single flight. Additionally, the Raptor engines burn liquid oxygen and liquid methane, neither of which is toxic to the environment.

To mitigate the environmental impact of its Starship spacecraft, SpaceX is exploring the possibility of collecting methane from the atmosphere to use as fuel. By using methane already present in the atmosphere and converting it into CO2, SpaceX could help decrease overall greenhouse gas emissions.

The Falcon 9 rocket uses kerosene, which creates black soot

The Falcon 9 rocket, developed by SpaceX, uses a fuel mixture of liquid oxygen and rocket-grade kerosene (RP-1). Kerosene is a refined form of kerosene containing a relatively narrow mix of hydrocarbons rather than the wider spectrum found in common kerosene. While liquid oxygen does not harm the skies, the black soot created by the burning of kerosene is injected directly into the stratosphere, the layer of air ranging from 12 km (7.5 mi) to 50 km (31 mi) above the Earth. This soot can linger for up to five years, absorbing heat, contributing to climate change, and damaging the ozone layer, which in turn exposes the planet to dangerous ultraviolet (UV) radiation.

The use of kerosene in the Falcon 9 rocket has been a source of environmental concern. Kerosene is chosen as a fuel because, until 2007, there were no methane engines available. Additionally, kerosene possesses several advantageous characteristics: it is cheaper, denser, stable at room temperature, easy to handle, non-toxic, easily transportable, and has no leakage issues like liquid hydrogen. Kerosene also has a higher energy density and presents a lower explosion hazard, making it a more cost-effective option in terms of thrust per dollar.

However, the environmental impact of kerosene cannot be overlooked. As mentioned earlier, the black soot produced by burning kerosene contributes to air pollution and has long-lasting effects on the atmosphere. The aviation industry, including rocket launches, plays a significant role in releasing atmospheric pollutants. While individual rocket launches may contribute less compared to the annual fuel consumption of airplanes, the type of fuel and the altitude at which it is burned have significant implications. Soot from airplane exhaust at lower altitudes precipitates quickly, while soot injected into the stratosphere by rockets remains for much longer periods, absorbing heat and altering the climate.

To address the environmental concerns associated with kerosene, SpaceX has been transitioning to cleaner fuel alternatives. The company's newest rocket, the Starship, uses methane (CH4) and liquid oxygen (LOX) as fuel. Methane burns cleaner than kerosene, producing less black soot. Additionally, methane has a higher energy density by mass, although it is about one-fourth the energy density in terms of volume. By adopting methane engines, SpaceX aligns with the growing need to reduce the environmental footprint of space exploration and contribute to more sustainable practices in the industry.

The Kazakh Steppe is an ecological disaster zone due to rocket fuel

While NASA has not been explicitly mentioned in relation to air pollution in Kazakhstan, the country has identified at least two major ecological disasters within its borders: the shrinking of the Aral Sea and radioactive contamination at the Semipalatinsk nuclear testing facility. The Soviet government used Kazakhstan as its nuclear testing site, and the country's enormous semi-arid steppe, the Kazakh Steppe, was subject to rocket launches from the Baikonur Cosmodrome, the world's oldest spaceport. The rockets launched from Baikonur contributed to the country's ecological issues, as vast amounts of toxic rocket fuel, including UDMH (unsymmetrical dimethylhydrazine), seeped into the soil. UDMH, also known as "devil's venom," is highly carcinogenic and is blamed for turning a large area of the steppe into an ecological disaster zone.

The Kazakh Steppe, a vast area of grassland stretching from northern Kazakhstan into Russia, has been impacted by rocket launches since the Baikonur Cosmodrome launched the world's first artificial satellite and the first human spaceflight, Sputnik 1 and Vostok 1, respectively. The rockets used a fuel called UDMH, which was favored by Soviet scientists for its stability and high energy output. However, UDMH is extremely toxic, earning the nickname "devil's venom." When UDMH spilled from the Proton rockets during launch, it rained down on the grasslands, poisoning the soil for decades. This has had severe ecological consequences, with activist Kopak highlighting the risk of falling debris and fuel wakes for the local population, who are predominantly herders and farmers.

The environmental impact of rocket launches from Baikonur has been exacerbated by the absence of pollution controls and the practice of discarding rocket stages over land rather than water, as is common at other spaceports. The Kazakh government has been accused of covering up the negative consequences of the Russian space program, including the presence of toxic materials and fuel wakes of heptyl. The ethnic composition of the cosmonauts, predominantly Russian, and the local population, predominantly Kazakh herders and farmers, has also been a source of tension and stratification.

The ecological issues in Kazakhstan extend beyond the Kazakh Steppe, with the country facing challenges such as industrial pollution, agricultural runoff, and radiation from nuclear testing sites. International efforts, such as the $86 million NAS project, have aimed to mitigate the environmental damage, particularly around the Aral Sea. However, Kazakhstan's cooperation with international programs to save the Aral and Caspian Seas has been limited. The country's Ministry of Environmental Protection also faces challenges due to underfunding and low priority.

While rocket launches from Baikonur have contributed to the ecological issues in the Kazakh Steppe, it is important to note that the aviation industry burns 100 times more fuel annually than all global rocket launches combined. Additionally, the space industry is making efforts to transition to cleaner fuels, such as liquid methane and bio-propane, which produce fewer emissions and less soot. However, the benefits of space exploration and the economic gains it brings must be weighed against the environmental impact, particularly in regions like the Kazakh Steppe, where the consequences of rocket fuel pollution are acutely felt.

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