Space Exploration: Worth The Environmental Cost?

The space industry has long been considered government-focused, similar to national security and defence. However, with the rise of space tourism, the industry is rapidly changing. As the number of rocket launches per year increases, so do concerns about the environmental impact of space exploration. Rockets propelled by fossil fuels emit a variety of substances into the atmosphere, including carbon dioxide, water, chlorine, and other chemicals, contributing to ozone depletion and climate change. While the current amount of pollution generated by space missions is considered negligible compared to other industries, the projected growth in rocket launches and the shift towards space tourism could have unforeseen effects on Earth's climate and ozone layer.

Rocket launches produce carbon emissions and soot

Rocket launches are a major contributor to carbon emissions and soot pollution. The burning of solid rocket fuels during launch can result in a hefty carbon footprint. While some rockets use liquid hydrogen fuel, which produces 'clean' water vapour exhaust, the production of hydrogen itself can still lead to significant carbon emissions. Additionally, rocket engines release trace gases and particles of soot into the upper atmosphere, contributing to ozone depletion.

The impact of rocket launches on the environment is significant, especially with the growing popularity of space tourism. The increase in rocket launches will result in a substantial amount of carbon dioxide being released into the upper atmosphere, where it can remain for years. For instance, a SpaceX Falcon 9 rocket launch can produce up to 300 tons of carbon dioxide. The carbon footprint of a single passenger on a sub-orbital exploration can be equivalent to that of a passenger flying thousands of times between Los Angeles and London.

Furthermore, the soot particles emitted by rockets have a considerable warming effect on the atmosphere. Particles released by rockets are almost 500 times more efficient at holding heat in the atmosphere than other sources of soot. This enhanced warming effect can disrupt the ozone layer and alter atmospheric circulation patterns, leading to potential changes in global climate patterns.

The type of fuel used in rockets also plays a role in the level of emissions produced. For example, SpaceX's Falcon 9 rocket uses kerosene, while NASA's new Space Launch System uses liquid hydrogen. Kerosene-based fuels tend to produce more soot than their counterparts. However, companies like Orbex are exploring the use of bio-propane, a renewable biofuel that can significantly reduce emissions and soot production.

While the space industry's impact on the environment is a growing concern, it is important to note that the number of rocket launches is still relatively small compared to other industries. Additionally, new technologies and alternative fuels are being developed to mitigate the environmental impact of space exploration.

Space tourism's environmental impact

Space exploration has been criticised for its contribution to pollution, particularly as rocket launches are known to produce harmful emissions. The impact of space tourism on the environment is a growing concern, with some scientists arguing that the increase in rocket launches will expose people in the Northern Hemisphere to increased harmful UV radiation and change atmospheric circulation patterns.

The environmental impact of space tourism is expected to be significant, with the number of space tourism flights predicted to increase rapidly over the next decade. Virgin Galactic, for example, aims to eventually launch 400 flights annually, with Blue Origin and SpaceX also envisioning substantial growth. These flights' effects on the environment will depend on factors such as the fuel used, the energy required to manufacture that fuel, and their destinations.

The emissions from a flight into space are considerably higher than those of a typical airplane flight. With only a few passengers on board, the emissions per passenger are much higher, resulting in a carbon footprint close to 100 times higher than a long-haul flight. This problem will be exacerbated if space tourism becomes more popular, as anticipated.

The fuel used by rockets is a critical factor in their environmental impact. Some rockets use liquid hydrogen fuel, which produces 'clean' water vapour exhaust. However, the production of hydrogen can lead to significant carbon emissions, and the engines release trace gases that contribute to ozone depletion and particles of soot. Other rockets burn rubber, leaving behind a cloud of soot, or use hydrocarbon-based fuels, which are known to damage the ozone layer.

While the current impact of rocket launches on the atmosphere is considered negligible due to the low number of launches, the projected increase in space tourism has scientists concerned about the potential harm to the environment. The benefits brought by the space industry must be weighed against the potential ecological disaster that could occur if not properly managed.

Fossil fuels in space exploration

Fossil fuels are currently used in space exploration, and they are a significant contributor to the carbon footprint of rocket launches. The burning of solid rocket fuels, such as UDMH, releases trace gases and soot particles into the upper atmosphere, which deplete the ozone layer and enhance the warming of the climate. However, it is important to note that the space industry's contribution to atmospheric emissions is relatively small compared to other industries, such as commercial aviation.

The use of fossil fuels in space exploration has come under scrutiny due to its environmental impact. As a result, there is a growing interest in exploring sustainable and clean alternatives, such as solar energy and biofuels. Solar energy, in particular, has gained traction as it is abundant, renewable, cost-effective, and does not produce harmful emissions. The use of solar panels in space missions can provide a reliable and predictable source of power without the need for ongoing fuel or maintenance.

Additionally, companies like Virgin Orbit and Orbex are experimenting with renewable biofuels, such as bio-propane, which is created as a waste product from biodiesel production. These alternative fuels have the potential to significantly reduce emissions and soot production, contributing to a more sustainable space industry.

While the adoption of these alternative energy sources for space exploration is still in its early stages, initiatives like NASA's Green Propellant Infusion Mission (GPIM) are working to develop and test greener alternatives to traditional rocket fuels. GPIM's road test of AF-M315E, a non-toxic and environmentally friendly alternative to hydrazine, is a step towards powering future missions with sustainable fuels.

In conclusion, while fossil fuels have been a mainstay of space exploration, the industry is gradually moving towards more sustainable alternatives. The development and utilization of clean energy sources, such as solar power and biofuels, have the potential to reduce the environmental impact of space exploration, making it more environmentally friendly and sustainable in the long run.

Solid rocket fuels and ozone depletion

Space exploration has been a topic of fascination and intrigue for decades, but it also raises important questions about its environmental impact. Solid rocket fuels, in particular, have been identified as a contributor to ozone depletion, which warrants further examination.

Solid rocket fuels have been a subject of concern due to their potential impact on the ozone layer. Rocket launches release large amounts of gases and particles into the upper atmosphere, including trace gases that contribute to ozone depletion and particles of soot. Solid rocket fuels are considered more harmful to the ozone layer than liquid rocket fuels. This is because solid rocket fuels are more durable and do not require specific storage conditions, making them more convenient for use but potentially more damaging to the environment.

The ozone layer is crucial for protecting life on Earth by absorbing a significant portion of the sun's ultraviolet radiation. However, human activities, including rocket launches, have led to ozone depletion, thinning the layer and allowing more harmful UV rays to reach the Earth's surface. This increase in UV radiation can have detrimental effects on human health, ecosystems, and the climate.

Recent studies have provided valuable insights into the impact of rocket launches on the ozone layer. Research by M.N. Ross et al., titled "Observation of Stratospheric Ozone Depletion Associated with Delta II Rocket Emissions," and published in "Geophys. Res. Lett." in 2000, specifically addressed this issue. Additionally, a 2017 study at NOAA, co-authored by Ross, examined the climate response to water vapour emissions from a proposed reusable space launch system utilizing cleaner hydrogen-fuelled rockets. This study emphasized the significance of ozone depletion caused by soot particles emitted by liquid-fuelled rockets, challenging the previous belief that only solid-fuelled rockets posed a threat to the ozone layer.

While the impact of space launches on the ozone layer is a cause for concern, it is important to note that rocket launches are relatively infrequent compared to other industries. Additionally, efforts are being made to explore new ways of launching satellites, such as horizontal launches or slingshot methods, which could help reduce the environmental impact of space exploration. Furthermore, companies like Orbex are focusing on using renewable biofuels, such as bio-propane, which can significantly reduce emissions and soot production compared to traditional rocket fuels.

Space junk and its consequences

Space junk, also known as space debris, is any piece of machinery or debris left by humans in space. It can refer to large objects such as dead satellites that have failed or been left in orbit at the end of their mission. It can also refer to smaller objects, like bits of debris or paint flecks that have fallen off a rocket.

Since the dawn of the space age in the 1950s, thousands of rockets have been launched, and even more satellites have been sent into orbit. Many are still there, and we face an ever-increasing risk of collision as we launch more. Orbiting our planet are thousands of dead satellites, along with debris from all the rockets that have been launched over the years. This could pose an issue one day.

Space junk can hinder scientific exploration. A significant amount of space junk has been left on the moon, which can make it difficult to set up camp and implement new technologies to execute more advanced missions and exploration of space. It can also interfere with existing satellites in orbit, potentially deterring the safety of astronauts who live on the International Space Station (ISS). The ISS has had to carry out collision avoidance manoeuvres to avoid getting damaged by space junk.

Space junk is a direct result of human activity, and it remains in orbit until it re-enters the atmosphere. Some objects in lower orbits can return quickly and will often re-enter the atmosphere after a few years, burning up so they don't reach the ground. However, debris or satellites left at higher altitudes of 36,000 kilometres can continue to circle the Earth for hundreds or even thousands of years.

Several companies have come up with solutions to tackle the problem of space junk. These include removing dead satellites from orbit and dragging them back into the atmosphere, where they will burn up. Methods to achieve this include using a harpoon, net, magnets, or lasers to heat up the satellite and increase its atmospheric drag so that it falls out of orbit. Japan's space agency, JAXA, is testing an electronic space whip that stretches six football fields long, known as the electrodynamic tether (EDT). This electrified line is intended to knock debris out of orbit, sending it to burn up in the Earth's atmosphere.

Frequently asked questions