Universal high speed internet access – or a sky full of debris
Soon, all our constellations could be LEO
What they are
Thousands of satellites in Low-Earth Orbit (LEO), able to provide high-speed internet and communication access around the world.
How they work
The technology has long been known; but in recent years the cost of constructing and deploying satellites has decreased,1 with particular advances in the deployment of small satellites.2 A key benefit of their small size is that it dramatically reduces the cost to launch them into orbit, particularly to LEO (<2,000km), which requires less energy to reach than does geosynchronous orbit (GEO) ~36,000km, historically used for GPS and communications satellites.3
This low orbit also reduces the latency (delay) in communication between a ground station and a satellite, compared with older satellites at higher orbits, proving superior even to fibre optic cable, particularly over long distances.4 LEO satellites, however, are not geo-stationary and orbit the Earth quickly (~90 minutes), which means that hundreds of satellites have to be deployed for a functional network.5 The antennas have to be ‘smart’ enough constantly to pick up new signals.
While large satellite constellations in LEO are not new,6 there has been a recent increase in the scale and number of proposed mega-constellations, with the current proposals set to vastly multiply the number of orbiting satellites.7 Whilst consumer broadband is frequently mentioned, the IoT,8 maritime and aviation industries,9 and mobile 5G10 providers will all be end users.
Many companies are developing mega-constellations, some more successfully than others, including: SpaceX,11 SES S.A,12 TeleSat,13 Amazon,14 OneWeb,15 Samsung,16 Boeing,17 LEOSat,18 and the China Aerospace Science and Technology Corporation.19
Implications and issues
Large numbers of satellites orbiting at very low altitudes present a number of issues, perhaps most importantly the possibility of dramatically increasing the amount of space debris, limiting future exploitation of space. Other issues include:
- Closing the digital divide. Providing internet access to the ~3.6 billion people who currently lack it has the potential to promote global development,20 and the global economy.21
- Science. Many observers worry about the impact that thousands of satellites will have on astronomy, complicating both visual and radio observation.22
- Regulation. There are limited international legally-binding rules on how to deploy satellite mega-constellations.23 However, national bodies must grant approval if they are to provide a service to that country, e.g. The Federal Communications Commission in the US.
- Investment in expanding or existing geosynchronous orbiting satellites has stalled.24
- Maintenance. Due to higher atmospheric drag in LEO as opposed to GEO, satellites must continually be replaced, because they fall out of orbit every few years, which is expensive.25
- Terminal costs. Phased-array antennae capable of tracking fast-moving LEO satellites are expensive and require further development.26
- Space debris. There are many satellites orbiting Earth,27 in addition to a large amount of orbiting debris.28 There have already been crashes between satellites. Adding thousands more satellites raises the risk of a chain-reaction of collisions considerably.29 End-of-life management is vital to avoid this.30
Our skies will look very different in the next 10 years, as will our access to internet and communications. Satellite mega-constellations could represent an incredible gain for billions of people, provided risks to science and space traffic safety are carefully managed, and the market continues to develop.
1 A key difference between the large satellites which are sent into GEO and the small satellites being sent into LEO is the degree of standardisation, which enables manufacturers to bring in many aspects of mass production which have not previously been applied to satellites. See, Caleb, H., 2016, Modernizing Manufacturing: How to Build the Satellite of the Future. Via Satillite [online] Available at: <http://interactive.satellitetoday.com/via/april-2016/modernizing-manufacturing-how-to-build-the-satellite-of-the- future/> [Accessed 9 April 2020].
2 Cubesats are very small satellites (10cm3) pioneered for scientific and educational use, although they have found increasing use as very low data-rate communications for Internet of Things devices. SmallSats are slightly larger than that and provide increased functionality. See, Mabrouk, E., 2017. What are SmallSats and CubeSats? NASA [online] Available at: <https://www.nasa.gov/content/what-are-smallsats-and-cubesats> [Accessed 7 April 2020].
3 Geosynchronous orbit is approximately 36,000km above sea level. Here a satellite will follow the Earth’s rotation, remaining above the same point on Earth as it rotates. Geostationary is slightly different and refers to those geosynchronous satellites at the equator. See, Howell, E., 2015. What Is a Geosynchronous Orbit? Space.com [online] Available at: <https://www.space.com/29222- geosynchronous-orbit.html> [Accessed 9 April 2020] and Riebeek, H., 2009. Catalog of Earth Satellite Orbits. NASA Earth Observatory [online] Available at: <https://earthobservatory.nasa.gov/features/OrbitsCatalog> [Accessed 10 April 2020].
4 Latency refers to the time taken between transmitting and receiving a signal. Ensuring low latency is particularly important for certain industries, such as financial trading, where shaving milliseconds from a signal can be highly valuable. Comparisons between the latency in LEO, MEO, and GEO can be seen in the following, Telesat Canada, 2019. Telesat LEO Latency Comparison 9. Vimeo [online] Available at: <https://vimeo.com/316629703> [Accessed 9 April 2020] and Dev, R., 2012. LEO, MEO & GEO Satellite Systems : A Comparison. Durofy [online] Available at: <http://durofy.com/leo-meo-geo-satellite-systems> [Accessed 9 April 2020].
5 The required speed needed to maintain a stable orbit diminishes with distance. Satellites in geostationary orbit (~36,000km) travel at around 11,000kmph, those in low earth orbit must travel at 27,000kmph, completing an orbit of the Earth in 90-120 minutes. That means each individual satellite is only in direct contact with a ground transmitter for a brief period, and is why LEO projects involve so many satellites. Signals are handed from one satellite to another, via laser, and ground antennae must automatically switch between satellites.
6 From 1998 Iridium Communications launched 65 satellites into LEO (~780km) to serve satellite phones and communications. They subsequently went bankrupt due to a lack of consumer market. After being purchased for a fraction of their invested costs they began to make a profit and have recently finished an overhaul of their constellation. See, Lim, J., Klein, R., & Thatcher, J., 2005. Good Technology, Bad Management: A Case Study Of The Satellite Phone Industry. Journal of Information Technology Management [e-journal] Available at: <https://jitm.ubalt.edu/XVI-2/article5.pdf> [Accessed 7 April 2020].
7 For a broad discussion on the topic and relatively up to date numbers on companies’ applications see, Wilson, R. S., et al., 2019. Space traffic management in the new space era. Journal for Space Safety Engineering [e-journal] Available at: https://doi.org/10.1016/j.jsse.2019.05.007.
8 For more on the Internet of Things (IoT) see Cameron, J., Llewellyn, P., 2019. Internet of Things. Llewellyn Consulting; and for information specific to the IoT and LEO satellite constellations see the following report from IoTUK, 2017. Satellite Technologies For Iot Applications. IOTUK [online] Available at: https://iotuk.org.uk//wp-content/uploads/2017/04/Satellite-Applications.pdf [Accessed 2 May 2020].
9 For discussion of the impact of LEO constellations on aviation see, Lightstone, P., 2020. Launching global coverage, new aircraft connectivity options. Wings magazine [online] Available at: https://www.wingsmagazine.com/launching-global-coverage-new- aircraft-connectivity-options/> [Accessed 2 May 2020], and Aero Connectivity – Reimagined with Telesat LEO. Telesat [online] Available at <https://www.telesat.com/sites/default/files/leo/aero_connectivity_reimagined_with_telesat_leo.pdf> [Accessed 2 May 2020]. For information on the impact of LEO constellations on the maritime industry see Wyngrove, M., 2020. New satellites boost ship connectivity. Riviera Maritime Media [online] Available at: <https://www.rivieramm.com/news-content-hub/new- satellites-boost-ship-connectivity-58553> [Accessed 2 May 2020].
10 For discussion on the application of LEO constellations for 5G see, Soret, B., 2019. LEO Small-Satellite Constellations for 5G and Beyond-5G Communications. DeepAI. [online] Available at: <https://deepai.org/publication/leo-small-satellite-constellations-for- 5g-and-beyond-5g-communications> [Accessed 2 May 2020].
11 Starlink, both the most developed and the largest of the proposed mega-constellations is being deployed by SpaceX. It hopes to put 42,000 small satellites into LEO in three separate layers (~350km, ~550km& ~1,200km) and provide internet, phone and other communications access worldwide, each using a different part of the microwave spectrum. It currently has approval for 12,000 satellites and paperwork for another 30,000 filled with the International Telecommunication Union. A clunky but relatively clear outline of how this is proposed to work is in the following. Mosher, D., 2019. Elon Musk just revealed new details about Starlink, a plan to surround Earth with 12,000 high-speed internet satellites. Here’s how it might work. Business Insider [online] Available at <https://www.businessinsider.de/international/spacex-starlink-satellite-internet-how-it-works-2019-5/?r=US&IR=T> [Accessed 7 April 2020].
12 Although not an owner of a LEO constellation, Luxembourg-based SES S.A. is a long-time player in the satellite television industry, with two constellations; with 20 satellites in Medium Earth Orbit (MEO) and 50 in GEO. With their purchase of One3B, (their 20 MEO satellites) they are aiming to provide mobile and internet access to a wider market. See, SES, 2002. Our Coverage. SES S.A. [online] Available at: <https://www.ses.com/our-coverage#/> [Accessed 9 April 2002] and Henry, C., 2020. SES mulls external investments for O3b, Networks business. SpaceNews [online] Available at: <https://spacenews.com/ses-mulls-external- investments-for-o3b-networks-business/> [Accessed 9 April 2020].
13 Telesat currently operate a fleet of 16 geostationary satellites which provide television broadcasting and communications services. They have applied for a constellation of 292 LEO satellites but have delayed selecting a manufacturer. See, Henry, C., 2018. Telesat says ideal LEO constellation is 292 satellites, but could be 512. SpaceNews [online] Available at: <https://spacenews.com/telesat-says-ideal-leo-constellation-is-292-satellites-but-could-be-512/> [Accessed 8 April 2020] and Caleb, H., 2019. Telesat LEO manufacturing decision bumped to 2020. SpaceNews [online] Available at <https://spacenews.com/telesat-leo-manufacturing-decision-bumped-to-2020/> [Accessed 8 April 2020].
14 Under the name of “Project Kuiper”, Amazon is planning to launch 3,236 broadband satellites into three separate layers, 784 satellites at 367 miles, 1,296 satellites at 379 miles, and 1,156 satellites at 391 miles, although timelines have yet to be determined. See, Henry, C., 2019. Amazon lays out constellation service goals, deployment and deorbit plans to FCC , SpaceNews [online] Available at: <https://spacenews.com/amazon-lays-out-constellation-service-goals-deployment-and-deorbit-plans-to-fcc/> [Accessed 5 April 2020].
15 The UK-based OneWeb planned a constellation of around 650 satellites but the company filed for bankruptcy in March 2020. It still maintains the 74 already-launched satellites. See, Henry, C., 2020. OneWeb files for Chapter 11 bankruptcy. SpaceNews [online] Available at: <https://spacenews.com/oneweb-files-for-chapter-11-bankruptcy/> [Accessed 5 April 2020].
16 The president of Samsung Research America outlined a plan for a constellation of 4,600 LEO satellites in 2015. See, Gershgorn, D., 2015. Samsung Wants To Blanket The Earth In Satellite Internet Data for all. Popular Science [online] Available at: <https://www.popsci.com/samsung-wants-launch-thousands-satellites-bring-everyone-earth-internet/> [Accessed 7 April 2020].
17 Boeing applied to the US Federal Communications Commission to put ~3,000 satellites in a constellation in 2016, since then they have not moved forward but have invested in Australian start-up Myriota’s 50 satellite constellation focused on Internet of Things services. See, Caleb, H., 2018. Boeing constellation stalled, SpaceX constellation progressing. SpaceNews [online] Available at <https://spacenews.com/boeing-constellation-stalled-spacex-constellation-progressing/> [Accessed 7 April 2020] and Etherington, D., 2020. Myriota raises $19.3 million to expand its IoT satellite constellation. TechCrunch [online] Available at: <https://techcrunch.com/2020/04/06/myriota-raises-19-3-million-to-expand-its-iot-satellite-constellation/> [Accessed 7 April 2020].
18 Softbank funded LEOsat had also planned to field around 300 LEO satellites but declared bankruptcy in late 2019. See, Henry, C., 2019. LeoSat, absent investors, shuts down. SpaceNews [online] Available at: <https://spacenews.com/leosat-absent-investors- shuts-down/> [Accessed 8 April 2020].
19 Announced in 2018 the “Hongwan” constellation will be comprised of 300 small satellites in LEO. The project is a collaboration between Thailand’s Kasetsart University and the China Great Wall Industry Corp, a China Aerospace Science and Technology Corporation subsidiary. Del Rosario, J., 2018. China’s Leo Constellation Ambitions. Northern Sky Research [online] Available at: <https://www.nsr.com/chinas-leo-constellation-ambitions> [Accessed 7 April 2020].
20 The International Telecommunication Union (the United Nations specialized agency for information and communication technologies) estimates that at the end of 2019 approximately 53.5% of the world population had access to the internet. See, Albertini, M., 2019. New ITU data reveal growing Internet uptake but a widening digital gender divide. International Telecommunication Union [online] Available at: <https://www.itu.int/en/mediacentre/Pages/2019-PR19.aspx> [Accessed 9 April 2020].
21 Estimates from investment banks suggest that the space economy as whole could reach $1–2.7 trillion. Although satellites comprise a majority of the current $350 billion space economy, many suggest that value will primarily derive from tourism and data applications. Internal documents from SpaceX show expectations of $36 billion in annual revenue from Starlink by 2025. See, Lluc Palerm, 2019. Will Leos Create A Trillion-Dollar Industry? Northern Sky Research [online] Available at: <https://www.nsr.com/will- leos-create-a-trillion-dollar-industry/> [Accessed 7 April 2020] and Foust, J., 2018. A trillion-dollar space industry will require new markets. SpaceNews [online] Available at: https://spacenews.com/a-trillion-dollar-space-industry-will-require-new-markets> [Accessed 7 April 2020]. Winkler, R., and Pasztor, A., 2017. Exclusive Peek at SpaceX Data Shows Loss in 2015, Heavy Expectations for Nascent Internet Service. Wall Street Journal [online] Available at: <https://www.wsj.com/articles/exclusive-peek-at-spacex- data-shows-loss-in-2015-heavy-expectations-for-nascent-internet-service-1484316455> [Accessed 7 April 2020].
22 So far, only SpaceX has announced that they will begin testing coatings which reduce reflectiveness (albedo) on their Starlink satellite constellations, but it remains to be seen if this will be enough, or if competitors will follow suit. For reports of scientists’ concerns see, The International Astronomical Union, 2019. IAU Statement on Satellite Constellations, iau.org [online] Available at:
<https://www.iau.org/news/announcements/detail/ann19035/> [Accessed 5 April] and Koller, J., Riesbeck, L., & Thompson, R., 2020. The Future Of The Night Sky: Light Pollution From Satellites. The Aerospace Cooperation , [online] Available at
<https://aerospace.org/paper/future-night-sky-light-pollution-satellites> [Accessed 5 April 2020]. Reporting on SpaceX’s albedo reduction promise is in the following, Arevalo, E. 2020. Elon Musk says SpaceX Starlink satellites ‘albedo will drop significantly on almost every successive launch’. Tesmanian [online] Available at: <https://www.tesmanian.com/blogs/tesmanian-blog/elon-musk- starlink-spacex> [Accessed 5 April 2020].
23 The International Telecommunications Union coordinates the allocation of frequencies for communications. The primary rule is that “systems will be required to deploy 10 per cent of their constellations within two years from the end of the current period for bringing into use, 50 per cent within five years, and complete the deployment within seven years.” However, there is no agreement on design principles such as reflectiveness, which impact upon astronomical observation. See, International Telecommunications Union, 2019. ITU World Radiocommunication Conference adopts new regulatory procedures for non-geostationary satellites. ITU [online] Available at <https://www.itu.int/en/mediacentre/Pages/2019-PR23.aspx> [Accessed 9 April 2020]. For a call for greater regulation see, Rimmer, A., 2020. You can’t take the sky from me. The Space Review [online] Available at: <https://www.thespacereview.com/article/3864/1> [Accessed 7 April 2020].
24 Expectation for large increases in satellite network capacity from emerging lower-altitude broadband constellations has caused market players to cancel some planned investments in new geosynchronous orbit broadband communications satellites. Recent theoretical models suggest that global internet coverage could be achieved with 4 satellites, albeit with higher latency than could be achieved with LEO constellations. See, Henry, C., 2018. LEO and MEO broadband constellations mega source of consternation. SpaceNews [online] Available at: <https://spacenews.com/divining-what-the-stars-hold-in-store-for-broadband- megaconstellations/> [Accessed 5 April 2020] and Del Rosario, J., 2017. Pricing The Satellite Markets. Northern Sky Research [online] Available at: <https://www.nsr.com/pricing-the-satellite-markets/> [Accessed 7 April 2020]. And for reports on GEO coverage see, Patel, N.V., 2020, Here’s how just four satellites could provide worldwide internet. MIT Technology Review [online] Available at: <https://www.technologyreview.com/2020/01/16/130832/heres-how-just-four-satellites-could-provide-worldwide- internet/> [Accessed 10 April 2020].
25 Because the atmosphere closer to Earth is thicker, those satellites in LEO have to cope with more atmospheric drag than satellites in higher orbits. This requires intermittent adjustment of altitude and eventually replacement of the satellite. This becomes a constant when managing a network of thousands of satellites. See, Space Weather Prediction Center. 2012. Satellite Drag. National Oceanic And Atmospheric Administration (NOAA) [online] Available at: <https://www.swpc.noaa.gov/impacts/satellite-drag> [Accessed 20 April 2020].
26 A vital part in making LEO constellations a success is the affordability of user terminals, the receiver and antennas customers will use to connect to the constellation. In contrast to geostationary satellites that always appear to hover at the same point in the sky, LEO broadband constellations will require antennas capable of tracking multiple satellites as they orbit overhead. Such antennas exist. In use for more than a decade, phased-array antennas commonly have no moving parts, relying instead on electronically steered beams to communicate with satellites. The technology is proven, but the cost is sky high. Although if recent announcements from the founder of the now-defunct OneWeb, of a $15 phased array antenna are true then this would contribute to solving one of the most pressing problems facing these constellations, finding a market. See, Henry, C., 2019. Wyler claims breakthrough in low-cost antenna for OneWeb, other satellite systems. SpaceNews [online] Available at: <https://spacenews.com/wyler-claims-breakthrough-in-low-cost-antenna-for-oneweb-other-satellite-systems/> [Accessed 8 April 2020] and Henry, C., & Werner, D., 2018. Does the satellite industry have antenna deficit disorder? SpaceNews [online] Available at: <https://spacenews.com/does-the-satellite-industry-have-antenna-deficit-disorder/> [Accessed 8 April 2020].
27 As of December 2019, there were approximately 2,300 active satellites orbiting Earth and approximately 3,000 inactive satellites currently orbiting Earth. See, European Space Agency, 2020. Space debris by the numbers, European Space Agency [online] Available at: <https://www.esa.int/Safety_Security/Space_Debris/Space_debris_by_the_numbers> [ Accessed 5 April 2020].
28 Approximately half of the current space debris orbiting Earth originates from two recent events, a 2007 anti-satellite test by the Chinese government, and an accidental collision between a decommissioned Russian satellite colliding directly with a member of the US Iridium constellation in 2009. Improving awareness of this debris is vital to continued use of LEO and space in general. The
U.S. Air Force has developed a ground-based radar system known as the Space Fence which is capable of detecting very small objects of space debris and should enable better avoidance of accidents. The Space Fence came online in early 2020. See, Peterson, G., Sorge, M., and Ailor, W., 2018. Space Traffic Management In The Age Of New Space. The Aerospace Corporation [online] Available at: <https://aerospace.org/paper/space-traffic-management-age-new-space> [Accessed 5 April]. For reporting on the Space Fence see, Erwin, S., 2020. Space Fence surveillance radar site declared operational, Space News [online] Available at: <https://spacenews.com/space-fence-surveillance-radar-site-declared-operational/> [Accessed 5 April 2020].
29 Originally suggested in 1978, the Kessler Syndrome suggests that if space becomes too crowded then any collision will produce a self-amplifying chain-reaction of further collisions. This will continue until space is no longer usable for satellites, or many other functions. See, Kessler, D. J., and Cour‐Palais, B. G., 1978. Collision frequency of artificial satellites: The creation of a debris belt, Journal of Geophysical Research [e-journal] Available at: https://doi.org/10.1029/JA083iA06p02637. More current analysis can be found in the following, Metz, M., et al., 2016. Risk to space sustainability from large constellations of satellites. Acta Astronautica, [e-journal] Available at: https://doi:10.1016/j.actaastro.2016.03.034.
30 Both NASA and the European Space Agency (ESA) funded studies have suggested that a 95-99% post-mission disposal is required to avoid a dangerous accumulation of space debris. See, Liou, J.-C., Matney, M. Vavrin, A., Manis, A., & Gates, D., 2018. NASA ODPO’s Large Constellation Study. NASA [online] Available at: < https://www.orbitaldebris.jsc.nasa.gov/quarterly- news/pdfs/odqnv22i3.pdf> [Accessed 9 April 2020] and Somma, G. L., Lewis, H.G.. & Colombo, C., 2018. Sensitivity analysis of launch activities in Low Earth Orbit. Acta Astronautica [e-journal] Available at: https://doi.org/10.1016/j.actaastro.2018.05.043.