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In this blog I will express my personal opinions, ideas and thoughts on topics related to Earth observation, remote sensing and space science in general. I will talk about current news and developments, and there may be more that is not yet known, even to me.

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Satellite Boom - It is Getting Crowdy!

Updated: Jul 28, 2023


Hello EO-Masters!

Have you ever looked up at the night sky and wondered how many of those bright dots are actually satellites? Well, you might be surprised to find out that there are more than 8,000 active satellites [How Many Satellites are Orbiting Around Earth in 2022?] orbiting the Earth right now, and thousands more that are defunct or debris. And that number is only going to increase, as more and more companies and countries launch their own satellites for various purposes, such as communication, navigation, observation, and exploration.


Earth orbit crowded with uncountable satellites and other space parts.
Earth orbit crowded with uncountable satellites and other space parts. (Generated by Midjourney)

Following the news that in the upcoming years thousands and thousands more will be launched into orbit it made me wonder if this is necessary? Is there no regulation? Does it need more regulation? What are the benefits and what are the risks of the satellite boom?

If you have similar questions, follow me on my search for answers in this blog. I’ve collected information from various sources to shed some light on it. I don’t promise that I can give you a final answer but at least some further insights.


Satellites and Satellite Constellations

Satellites fly more than 65 years around our planet. Satellite constellations started 30 years ago with the GPS constellation. A constellation is a group of satellites which works together as one system to achieve its mission. The number can vary from as low as 2 (TanDEM-X) and can go up to several thousands of satellites (Starlink). There are also plans for constellations of more than ten thousand [China is developing plans for a 13,000-satellite megaconstellation] or even more than 300 thousand [Wyler raises $50 million for “sustainable” megaconstellation] satellites.


Usage and Benefits

Besides experimental cases, satellites and constellations are mainly used for one of six use cases.


1. Earth Observation 2. Communication 3. Navigation 4. Weather 5. Telescope 6. Weapon


Constellations are especially used for communication and navigation purposes. They have certain advantages over single satellites. Increased Coverage. With multiple satellites in orbit, a satellite constellation can provide more comprehensive and continuous coverage. Improved Reliability. Multiple satellites in orbit can provide improved reliability, as the failure of one satellite can be compensated for by others in the network. Flexibility. A satellite constellation can be reconfigured as needed, allowing for the provision of different services or the optimization of coverage in specific areas. Lower Latency. A reduced latency can be achieved, as signals can be routed through the network, reducing the distance the signals need to travel. Cost Savings. By leveraging the benefits of economies of scale, satellite constellations can reduce costs compared to single satellites, as the cost of launching and operating multiple satellites can be spread across a larger network.

Satellites and satellite constellations can provide many benefits for humanity, such as global communication, improving internet access, weather forecasting, disaster management, and scientific research. This allows us to never miss a call from our granny again when being in the fields or we can check Instagram when sailing across the ocean. But it also allows for more serious applications like receiving severe weather warnings when being at the outer rim of civilization or letting sensors sent their collected data to the home station.


Ongoing and Planned Satellite Constellations

According to the NewSpace Index [Satellite Constellations - NewSpace Index] there are about 270 active commercial constellations planned. I arbitrarily selected 11 of them and provide them with a brief description in the table below. I’ve added IRIS2 to the list because it is not yet listed in the NewSpace Index.

Constellation

Organisation

Description

​#Satellites

Starlink (Gen 1)

SpaceX

Worldwide internet access

4408

OneWeb

Airbus / OneWeb

Worldwide internet access

648

Project Kuiper

Amazon

Worldwide internet access

>3,000

REC

SatRev S.A.

Real-time Earth Observation Constellation with a spatial resolution of 50cm and a revisit time of 30 min.

1,500

NEXT

Iridium

Worldwide mobile voice and data communications

75

Globalstar Gen 2

Globalstar Inc.

Worldwide mobile satellite services

42

O3b mPower

SES S.A.

Worldwide internet access

70

Xingyun

CASIC

IoT and tracking services in China

80

?

E-Space

Sustainable mega-constellation providing broadband services and able to capture and de-orbit debris

>300,000

Astra

Astra Space

Worldwide internet access

13620

IRIS2

ESA

Worldwide internet access

170

The list shows that there is a huge interest in the industry to take part in this new edition of a space-race. The enormous number of planned missions seem to indicate a growing bubble that could burst in the future. However, the roughly 20% of dormant and cancelled missions show also that it is not easy to be successful. But the list tells us also that we will face more than 50,000 satellites (excluding E-Space) in low Earth orbit in the upcoming years.


Do we need so many similar constellations?

When looking at the list, the first thing noticed is that most of the constellations are for communication and provide global access to the internet or allow mobile communication. Is it necessary to have so many similar missions? Is it necessary to have thousands of satellites? I do well understand that several companies want to have a share of this new big cake. Also, I understand that countries want to be independent of other countries. Communication and navigation are essential technologies for a society. And we have seen recently that dependency can lead to problems. This was the case with Europe's dependence on Russian gas supplies. Another case is the dependence of the West on China's supply of rare earths, or China's dependence on Western demand for goods.

It is understandable that are a few satellite constellation operators with the same objective. But that many? Probably the regulatory forces of the market will ensure that in the end only a few will survive. Even Starlink is losing money at the moment. About 20 million Dollar every month [Elon Musk Admits: Starlink Is Losing Money]. But until the market settles down, the sky will be full.

It is also a question if a single mission needs thousands of satellites. OneWeb needs only 648 and Iridium uses only 66. The number of satellites required for a constellation to provide global coverage depends on several factors, including the altitude of the satellites, the design of the constellation, and the capabilities of the individual satellites. Let's have a closer look at these three approaches.

OneWeb’s constellation is designed to provide global coverage with a comparably small number of satellites by placing them in a higher orbit than Starlink’s satellites. This allows each satellite to cover a larger area on the ground, reducing the number of satellites required for global coverage. OneWeb’s initial constellation is planned to have 648 satellites in a near-polar orbit at an altitude of 1,200 km.


In contrast, Starlink’s initial constellation is planned to have several thousand satellites in a lower orbit at an altitude of around 550 km. This allows for lower latency and higher data rates but requires more satellites to provide global coverage.


Iridium Next, on the other hand, uses a different approach with its constellation of 66 cross-linked satellites in a near-polar orbit at an altitude of 780 km. The cross-linking allows the satellites to communicate with each other and route traffic between them, reducing the number of ground stations required and allowing for global coverage with fewer satellites.


Each approach has its own advantages and disadvantages.


OneWeb (higher orbit with fewer satellites):

Advantages

Disadvantages

Fewer satellites are required, which can reduce the cost and complexity of the constellation.

​Higher latency due to the increased distance between the satellites and the ground.

Satellites in higher orbits have longer lifetimes and require less station-keeping fuel.

Lower data rates compared to constellations in lower orbits.


​​Starlink (lower orbit with more satellites):

Advantages

Disadvantages

​Lower latency due to the closer proximity of the satellites to the ground.

More satellites are required, which increases the cost and complexity of the constellation.

Higher data rates due to the use of higher frequency bands that are only usable over shorter distances.

Satellites in lower orbits have shorter lifetimes and require more station-keeping fuel.


Iridium Next (cross-linked satellites in a near-polar orbit):

Advantages

Disadvantages

Global coverage with fewer satellites due to the use of cross-links between satellites.

The cross-linking adds complexity to the satellite design and operation.

The near-polar orbit allows for coverage of polar regions that may be difficult to cover with other constellations.

The use of a near-polar orbit may result in reduced coverage in equatorial regions.

Looking at these pros and cons I can’t really say what the best option is. But it leaves the feeling that the thousands of satellites are not necessary. Especially when comparing OneWeb and StarLink [Starlink vs OneWeb: How Do They Compare?] and looking at the speed and latency they want to provide.


Starlink

OneWeb

Speed

Download: 50-200Mbps

Upload: 5-10 Mbps

Download: <150 Mbps

Upload: <20 Mbps

Latency

20 to 40 ms

~70 ms

The numbers are quite similar. Maybe Starlink is a bit ahead with its lower latency but is it worth to launch so many more satellites? Let me know what you think in the comments.


Problems, Risks and Danger

This number of satellites flying around planet Earth will pose some serious problems and risks. One of them is space congestion and the probability of collisions. As the number of satellites increases, so does the chance of them bumping into each other or into other objects, such as rocket parts, tools, or even paint chips. These collisions can create more debris, which can then collide with other satellites or debris, creating a chain reaction known as the Kessler effect [Kessler syndrome]. This could potentially render some orbits unusable or dangerous for future missions, and also threaten the safety of astronauts and spacecraft. Starlink had to perform an average of 140 collision avoidance manoeuvres per day between December 2022 and end-May 2023. This sums up to more than 25,000 manoeuvres in half a year. Experts predict that by 2028 Starlink needs to perform two million manoeuvres per year [SpaceX Starlink satellites caused 25,000 near-misses in just 6 months]. Is this still handleable? Another problem is that astronomy from Earth is becoming increasingly difficult to impossible [Satellite Constellations Are an Existential Threat for Astronomy]. Astronomical observations are affected by the reflection of sunlight from the satellites. Astronomers set up centre to build a joined force against the space industry and to protect the dark and quite sky from satellite constellation interference [Astronomers set up center to counter threat of satellite swarms].


This interference can reduce the visibility of stars and other celestial objects and hinder scientific research. Not only observations from ground are affected but also the Hubble Space Telescope is increasingly affected [Sandor Kruk - The impact of satellite trails on Hubble observations]. The use of more radio frequencies by satellite constellations can cause interference with other satellite systems and terrestrial communication networks. This makes a reliable communication with the satellites difficult and flying manoeuvres to coordinate the operation of the constellation will be more challenging. In case of failure, this can lead to further debris. Space debris can pose a risk to the atmosphere when it re-enters and burns up. During this process, debris can release chemicals that can have a harmful impact on the atmosphere, including the ozone layer.

The lack of proper regulation and coordination between the various actors in the space domain poses another risk. The absence of a global regulatory body allows for the uncontrolled flooding of Earth's orbit with more satellite constellations.

Solutions

What are potential solutions to the above problems? Starlink has already made attempts to help the astronomers. A satellited with a dark antireflective coating has been launched in 2020. It is half as bright as standard satellites made by Starlink. Already a big step, but not enough for the astronomers [SpaceX's Dark Satellites Are Still Too Bright for Astronomers]. Another way to reduce the impact on the scenes is that if astronomers know the exact orbit of the satellites, they can point their telescopes in a different direction that is not affected by the satellites. This is possible with a few thousand satellites, but not with tens of thousands [SpaceX Tests Black Satellite to Reduce "Megaconstellation" Threat to Astronomy].

A solution to the space congestion and the probability of collisions might be the regulation by the market also finding a meaningful number of used satellites will lower the importance of this issue. In addition, accurate accounting and close monitoring of orbits is required to initiate manoeuvres early and avoid collisions.

The Inter-Agency Space Debris Coordination Committee (IADC) is an international forum of national and international space agencies for the worldwide technical/scientific coordination of activities related to space debris in Earth orbit issues. The primary purposes of the IADC are information exchange on space debris research activities, facilitating opportunities for joint research, and reviewing progress of ongoing activities. This is not a solution to the problem but at least a starting point and to collect necessary information. A solution, at least to reduce the number of chemicals used, are satellites made of wood. Finnish and Japanese scientist are working on this, and the first launch shall happen soon [Scientists Are Officially Launching a Wooden Satellite, Space test shows magnolia may be best for wooden artificial satellite LignoSat].


Is more regulation needed?

More regulation could be another way to reduce the problems caused by the many satellites. The lack of a uniform and binding legal framework regulating the use and protection of orbit jeopardises the sustainable use of orbit. Although there are some international treaties and organisations dealing with space law, such as the UNOOSA, the ITU, the FCC, ESA and NASA, these are often insufficient, outdated or not universally recognised. As ESA and NASA are known to everyone and they play only a secondary role in the regulation game, let's have a look at the other players.


The United Nations Office for Outer Space Affairs (UNOOSA) is an office within the United Nations that serves as the secretariat for the General Assembly's Committee on the Peaceful Uses of Outer Space (COPUOS). Its main purpose of UNOOSA is to promote international cooperation in the peaceful uses of outer space, including satellite communication and earth observation, space science and technology, and the exploration and use of space for the benefit of all humanity.


The International Telecommunication Union (ITU) is responsible for the coordination of the use of the radio frequency spectrum for satellite and other telecommunications services, including the allocation of frequencies to different countries and satellite constellations. The ITU also works to promote the development of international satellite communications and to ensure that satellite networks and services are operated in a way that is safe, secure, and reliable. ITU also plays a role in promoting international cooperation in the development of space science and technology, and in the peaceful exploration and use of outer space. The ITU works closely with other international organizations, such as UNOOSA.


The Federal Communications Commission (FCC) is an independent agency of the United States federal government that regulates interstate and international communications by radio, television, wire, satellite. The FCC is responsible for regulating the licensing and deployment of satellite constellations and ensuring that they comply with technical, operational, and safety standards. The coordination of the use of the radio frequency spectrum for satellite communications on a global basis is done in collaboration with international organizations, such as the ITU.


In 1976 the Convention on Registration of Objects Launched into Outer Space (aka. Registration Convention) went into force and is ratified today by 72 states. Those states and international intergovernmental organizations are required to establish their own national registries and provide information on their space objects to the Secretary-General for inclusion in the United Nations Register. Responsibility for maintenance of the Register was delegated to the UNOOSA.

Even though there are these regulatory bodies, there is no instance which seems to be able to deny the operation of satellite constellations. E-Space, with its more than 300,000 planned satellites, has registered its plans with the ITU through the Rwanda Space Agency [Rwanda files with ITU for 327,000 satellites], despite being based in Toulouse, France. Why was Rwanda chosen? Is it because Rwanda is a newcome in the space business or is it because Rwanda has not signed the Registration Convention? Another strange example is that SpaceX was not patient enough to wait for FCC approval for its next batch of satellites. Instead, they used the German Bundesnetzagentur to register the new constellation [Starlink uses Germany to file for new satellites] (governmental approvals can be fast in Germany? 🤔).


These are just two examples of the strange regulation of the Earth’s orbit. Does it need to be improved? Yes, I think so. A central and international organisation, which could be a UNOOSA 2.0, would make it possible to regulate and protect the orbit and all parties involved. This organisation would be responsible for implementing and enforcing standards and guidelines for the use of orbit, such as limiting the number or size of satellites, allocating orbital positions or frequencies, establishing minimum distances or safety zones, reducing the lifetime or orbital altitude of satellites, or increasing the transparency and accountability of space activities. Some of these standards and guidelines have already been proposed or adopted by international organisations such as the UN, ITU or IADC, but they are often voluntary, incomplete, or not universally applied.


Conclusion

Satellite constellation cause problems but there are also solutions to them, at least to reduce the negative impacts. Possible solutions include developing better tracking and monitoring systems, implementing stricter standards and guidelines, increasing international cooperation and coordination, and designing more sustainable and responsible satellites that can avoid collisions, deorbit themselves, or be recycled or reused.

But ultimately, the solution lies in changing our mindset and attitude towards space. We need to recognize that space is not a limitless and free resource, but a finite and fragile one, that needs to be shared and protected by all. We need to balance the benefits and the costs of using space and ensure that our actions do not compromise the future of space exploration and utilization. We need to treat space as a common heritage of humankind, and not as a playground or a battlefield.

Despite the potential problems, the new satellite constellations also offer many benefits. For example, they can improve access to information and services for people in remote or underserved areas, facilitate monitoring of climate change and other global phenomena, advance exploration of space and the solar system, and create new opportunities for education, culture, and entertainment. These benefits should not be ignored or abandoned but should be used in a manner consistent with the protection of and respect for space and its inhabitants.


I’m not sure if I reached my goal, to get to definitive opinion on satellites constellation and if they are good or bad. Probably, as in most cases, the answer is not so clear. They offer many benefits, but the situation should not get out of hand. With more regulation, everything can still be fine.


Now it’s your turn. Have I missed something essential to mention or is something incorrect? Then let me know in the comments. I would also be interested in your opinion and if this blog changed it. Thanks for reading.


Tschüss!

Marco



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Marco Peters
Marco Peters
04 de ago. de 2023

Just found this article about the space debris problem. Space Debris Will Block Space Exploration unless We Start Acting Sustainably - Scientific American It sheds some more light on the debris problem.

Also, the ESA’S ANNUAL SPACE ENVIRONMENT REPORT was recently published, and ESA is acting. They have announced the Zero Debris Charter.

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