By Elisabeth Tweedie, Founder, Definitive Direction. As mentioned in a previous blog: “The Unsung Heroes of Battle,” the satellite industry is playing a significant role in combating climate change. That blog was written over a year ago, and since then several more satellites have been launched, increasing the amount of information gathered, and so furthering our knowledge as to where the major emissions of carbon dioxide and methane occur. Later this year, one company GHGSAT will launch a hosted payload satellite that will have the capability to pinpoint carbon emissions to individual industrial facilities, the same way that its satellites do this for methane emissions. Obviously, this information will be a huge boon to governments and local authorities committed to reducing their carbon footprint.

However, at the same time that the industry is playing such a major role in combatting climate change, concerns are being raised about its contribution to climate change. These concerns are focused on the pollution caused by the launch industry. Superficially, rockets play a small role in pollution. At the present time the aviation industry burns 100 times more fuel each year than the launch industry.  And the aviation industry itself is only responsible for 2.4% of annual carbon emissions, according to a recent report.

In the past with relatively few launches a year, the overall impact from the space industry was minimal. But as the industry is changing, so too are the number of launches. In 2022 there were approximately 180 successful launches, in the previous year there were 136, a growth of over 30% in just one year. With the shorter lifespan of low earth orbit satellites, there is no reason to expect this growth to slow. In addition, there’s space tourism, currently in its infancy. Virgin Galactic and Blue Origin, the two most advanced companies in this field, have already transported several paying passengers into space, and have indicated that once the business gets going properly (and there is a long waiting list of paying passengers) the intention is to provide at least one voyage a month at a minimum. (Some sources have suggested as many as two to three per week). There are other companies aspiring to join their ranks, including SpaceX, although right now, its intention is to take passengers to the moon.

This projected rapid growth in the number of launches alone, would be sufficient to cause concern; a quick back of the envelope calculation indicates that if the current growth rate continues, launches will be burning as much fuel as the aviation industry in less than five years. But that is not the issue.

The real issue stems from where the pollution occurs. All plane flights occur in the lowest level of the atmosphere, the troposphere. At this level pollutants tend to disperse in a few days; in the higher-level stratosphere and mesosphere, pollutants have a much longer life. Black carbon (soot) for example, rather than dispersing in a few days, can have a life of up to five years in the stratosphere. Research from the National Oceanic and Atmospheric Administration (NOAA) indicated that in 2022 1,000 tons of soot were produced by the 180 launches. More research is needed to determine the precise impact of the different pollutants at this level. One concern is that they could damage the ozone layer, by causing temporary or permanent holes. Even water vapor can be detrimental, if the clouds block sunlight from reaching the earth, changing the temperature, so leading to worsening summer monsoons in Africa and India.

Different launchers use different fuels. Some of the most common ones in use today are liquid hydrogen, kerosene, hydrazine and solid fuel. None of these are renewable and come with varying levels of concern. Hydrogen for example is one of the cleanest, as it only emits water vapor when it burns, which is less of a concern than soot. However, it isn’t classified as a “clean fuel” because current production methods are very carbon-intensive. Green hydrogen, which is a renewable fuel could be an alternative, but currently this only accounts for 1% of US hydrogen production.

The other three all produce soot. According to NOAA each passenger aboard a rocket is responsible for 100 times more climate-changing pollution than an airplane passenger.

I’m not going to go into which launch companies are using hydrogen as opposed to soot producing fuels. Suffice it to say, that according to the Aerospace Corporation, last year over half of all rocket fuel used was hydrocarbon based. What I am going to do is highlight a couple of companies that are thinking outside the box and developing engines that use novel fuels.

One of these is Orbex. Orbex is currently building the UK mainland’s first vertical launch site at Sutherland Spaceport in Scotland. Once completed this will be the home for its Prime rocket which will launch smallsats into low earth orbit. Prime will be powered by a renewable bio-fuel known as Futuria Liquid Gas. A study carried out by the University of Exeter indicated that a Prime launch will generate 96% less carbon emissions than a comparable launch using fossil fuel.

Another Scottish rocket company, Skyrora is developing a fuel, it’s named Ecosene, made from recycled plastic which cuts down 70% of the carbon footprint of traditional kerosene manufacture. Ecosene has already won several awards including the Environmental Best Practice Award at the Green Apple Environment Awards 2020.

Creating a reusable launch vehicle is another way of reducing the launch industry’s carbon footprint, or at least it should be, as manufacturing rockets is rarely a clean process. However, questions are now being raised about the environmental impact of the gasses produced during the reentry process. These questions will become more relevant as current constellations of LEO satellites come to the end of their useful life and, in many cases, burn up on reentry, producing not only gasses, but millions of small polluting particles, all of which will have some impact.

So, do we as an industry do more harm than good? At the moment, I would say emphatically “no.” Yes, we’re definitely contributing to climate change, but in a small way. If no action is taken our negative impact will grow, but hopefully so will our knowledge and willingness to migrate to more environmentally friendly fuels, as launch companies take the bold step of converting their engines in order to do so. On the other side of the coin, not only are we making a major contribution to furthering our knowledge and awareness of where damaging emissions are coming from, it must also be remembered that we play a major role in global communications and disaster mitigation.

Elisabeth Tweedie’s entire career has been focused on commercial satellites, telecommunications and broadcasting, specifically in the highly specialized area of evaluating the long term potential for new ventures, initiating their development and finding and developing appropriate alliances.

During the course of her career she has advised and worked with senior stakeholders in global and international businesses, governments and regulatory bodies. Her core expertise is in understanding new technology and its practical applications; identifying key drivers for both B2B and B2C markets and identifying, evaluating and developing JV opportunities.

Elisabeth has an MBA in International Marketing from the University of Aston (UK) where she graduated top of her class; she is a graduate of the University of Southern California’s Advanced Management in Telecommunications Program. Early in her career she authored numerous published multi-client reports on the market and economic aspects of telecommunications and media industries in Europe, Asia and North America and is currently Associate Editor of Satellite Executive Briefing.