Space is the new black
Emerging risks from the increasing use of space
Space is a megatrend. Right now we are witnessing more satellite launches than ever before. Space is becoming a mundane part of our everyday life, and in fact, many companies may even forget that they are using space-borne technologies in their processes. As society’s dependence from space increases, vulnerabilities also become evident. This article highlights the emerging risks that have recently materialised or may soon become a problem with the booming space economy.
The near-Earth space in the close vicinity of our planet is becoming crowded, as satellites are launched into orbit. Figure 1 shows all the satellites that have ever been launched into space. The colour of the bars in Figure 1 represents the motivation for launching each spacecraft. During the Cold War, approximately 150 satellites were launched annually, primarily for defense-related applications.
Since around 2015, annual launches have outnumbered those during the Cold War, and from 2020 there has been a rapid increase in the number of launches. The motivation for sending satellites has shifted to serve commercial purposes, as companies now seek to profit from space. Investment banks have estimated that the total value of the space economy could grow to 1.8 trillion dollars by 2035 [1], as the industry continues to launch new satellites. [2]
The change that has enabled the rapid growth of commercial space economy is the access to space, which was previously controlled by large countries or big organisations like the European Space Agency (ESA). The opening of the launch market changed the situation, and now many launches are arranged by brokers who seek a slot on a rocket for a fee. Another big change is the use of more cost-efficient off-the-shelf technology, which is making space more affordable for small and medium-sized companies [3] .
Space offers various business opportunities that are either more affordable compared to the earlier paradigm, or it enables new ways of doing business. Space is a global and scalable platform for customers from various backgrounds. Satellites are used in numerous services, including broadcasting, communications, positioning, navigation, timing, weather and climate monitoring, Earth observation, and defence. [4]
Space environment from the satellite perspective
Satellites do not fly in a vacuum, as the vicinity of the Earth is filled with the fourth state of matter, plasma, which consists of charged particles that are controlled by electromagnetic fields and other collective forces. Another aspect that satellite operators need to consider is space debris and other missions. This chapter concerns the space environment from the satellite’s perspective.
Debris: Figure 2 shows the total observed amount of debris in orbit around the Earth. The total mass is over 8000 tons, however; only objects larger than 10 cm in size can be tracked from the ground, while it is estimated that the total number of objects larger than 1 cm is over one million(5). Debris exists in those orbits which are most commonly used: Geostationary orbit (GEO, hosting e.g., weather satellites), Medium Earth Orbit (MEO, hosting e.g., navigation satellites), and on Low Earth Orbit (LEO, hosting e.g., Earth observation satellites).
The largest number of debris lies on LEO polar orbits, which circulate the Earth via the northern and southern hemispheres (Muelhaupt et al., 2019). One of the most hazardous orbits is between 700 – 1000 km altitude on LEO. Due to the high concentration of debris there, many future satellite launches are planned either above or below these altitudes, requiring either more sophisticated instruments, or more fuel, respectively, for commercial activities, and hence more costs for companies.
Both large and small debris objects are equally problematic for satellites. One of the most concerning big objects is the bus sized ESA Envisat(6), an uncontrollable ‘zombie satellite’ flying at approximately 750 km LEO orbit. Obviously, if Envisat collides with another satellite, the resulting debris would make the orbit so crowded that it could no longer be used for future satellites. However, small objects are also continuously harmful to satellites, for example they can create impact craters on solar cells and jam instruments(7).
The main threat from debris
The main threat from debris is the so-called Kessler syndrome (Kessler and Cour-Palais, 1978), meaning an incident where debris particles start to collide at a larger frequency, generating more particles while the total mass would stay unchanged. This could lead to an exponential increase in particles, forming a debris cloud around the Earth and making space unusable for satellites. The scientific community does not agree on the possible infliction point for Kessler syndrome; however, Envisat’s collision has been named as one potential trigger.
Often in relation to debris, international agreements or binding legislation are called for to regulate the use of space (e.g., Palmroth et al, 2021a). Internationally, only non-binding agreements exist. To launch a satellite, one must obtain a licence from the country where the satellite is registered, and these licences are granted under binding regulation that stipulates, for example, the risks posed to other satellites. Lately, the European Union, for example, has launched a ’space traffic management’ programme(8). However, agreeing on the approach takes time, meanwhile companies continue to launch satellites.
One option that companies are now looking at is the very low Earth orbit (VLEO), where atmospheric density is already high enough that satellite orbits decay naturally if fuel-based orbit maintenance is stopped. Launching to these orbits would keep the operating environment debris-free naturally. On the other hand, these altitudes are often called the “ignorosphere” (Palmroth et al 2021b), because it is hard to observe and predict. In the future, we may have tens of thousands of satellites in a region that the scientific community does not fully understand.
Space weather
Another environmental aspect that satellite operators must consider is space weather, i.e., the conditions in space which affect technological reliability or human health (e.g. Moldwin, 2022).
The Earth’s magnetic field interacts with the stream of particles coming from the Sun. Sometimes the Sun ejects large clouds of plasma, causing strong space weather variations on Earth, while the Earth’s magnetic field variability also contributes to space weather effects.
Broadly speaking, space weather manifests in a region where the aurora can be seen, i.e., in the two zones circling both hemispheres. The size of these auroral zones is directly proportional to the size of the space weather event. There are many small solar eruptions each year, a few medium-size events every decade, and one extreme event per century (see Fig. 3). The main impacts of space weather concern the electric power grid, satellites, and all electromagnetic signals.
The worst-case scenario
The worst-case scenario in space weather is an extreme event, such as the Carrington Event that was observed in 1859. During this event, a magnetometer in Mumbai, India, observed ground magnetic variations similar to those that tripped the power network in Malmö, Sweden, in 2003 (Nevanlinna, 2008).
Some reconstruction efforts have been made to understand what impacts such event would have on modern technology. While studies are ongoing, there are indications that power grids could be damaged (Ebihara et al 2021). Satellite impacts could be extensive (Odenwald et al, 2006), including lost spacecraft and/or lost signals.
Aviation could face global re-routings or cancellations due to high radiation exposure at flight altitudes (Xue et al 2023). In summary, the effects of a once-per-century extreme space weather could be very serious, given how dependent modern society is on satellite signals and electricity. The scientific community does not fully understand these extreme events because they have not been observed using modern instruments and because space weather models have been built to reproduce much milder conditions.
The occurrence frequency of extreme events is roughly once per century (Chapman et al 2020), and there is a scientific consensus that we are already on borrowed time. The event that gathered significant media attention in May 2024 was medium-sized and could have been about 4-5 times smaller than the Carrington Event. Even though the impact scenario might sound like the end of the world, many measures can be taken to prepare for extreme space weather. The first step is to understand whether a specific service or system depend on space weather and whether its effects can be mitigated.
For example, mobile networks that are only using satellite-based time synchronisation could face problems during an extreme event, while networks that are also using a ground-based atomic clock are more reliable. The most important point is to trust the preparedness professionals and add redundancy and built-in slack for critical systems (e.g., Roe and Schulman, 2008). The scientific community also welcomes questions and discussions, as this helps them understand new systems that depend on space weather.
Summary
In summary, the electrification and digitisation of societies are required for sustainability efforts. At the same time, many societal functions are increasingly reliant on launching satellites, which, in turn, are growing exponentially. These two trends make society increasingly vulnerable to space weather and space debris. It is recommended to assess whether individual services are dependent on space weather, and if so, to develop mitigation plans with space weather experts and preparedness professionals.
References:
Chapman et al. 2020 https://doi.org/10.1029/2019GL086524
Ebihara et al. 2021 https://doi.org/10.1186/s40623-021-01493-2
Kessler, D. and Cour-Palais, B., 1978 https://doi.org/10.1029/JA083iA06p02637
Muelhaupt et al. 2019 https://www.sciencedirect.com/science/article/pii/S246889671930045X
Moldwin, 2022 https://www.cambridge.org/highereducation/books/an-introduction-to-space-weather/CC822E727D563A79CF959F49E85214C2#contents
Nevanlinna, 2008 https://doi.org/10.1016/j.asr.2008.01.002
Odenwald et al. 2006 https://doi.org/10.1016/j.asr.2005.10.046
Palmroth et al. 2021a https://www.sciencedirect.com/science/article/pii/S0265964621000205
Palmroth et al 2021b https://doi.org/10.5194/angeo-39-189-2021
Roe and Schulman 2008 High Reliability Management: Operating on the Edge. Stanford University Press, Stanford
Xue et al. 2023 https://doi.org/10.1029/2022SW003381