Satellite constellations, a race is engaged

Covering 100% of the planet in Internet access from outer space, this is the project of several firms including SpaceX, Amazon and OneWeb; the objective is to send in Low Earth Orbit (LEO) thousands of small satellites or satellite constellations. Not all competitors are at the same level of progress in this project, with some satellites already in orbit by only two of them: OneWeb and SpaceX. In spite of technical difficulties, the firm of Elon Musk ended up launching its first sixty micro-satellites constituting its future constellation Starlink this Thursday, May 23, 2019.

What are satellite constellations?

A satellite constellation, also called a satellite swarm, is a system of satellites that work together to achieve a single purpose. For some purposes, a single satellite is fine. However, where constant contact with a point on the globe or instant global communication is required, a network of satellites may be needed to avoid latency and breaks in communication. Depending upon how high above Earth the satellite orbits, breaks can happen if a single communication point as it goes over the horizon and the planet blocks the signal. To ensure that a satellite for a given purpose is in contact at all times requires, more satellites must be deployed in orbit.

Most communications satellite constellations are geosynchronous, which means they are parked in an orbit above the equator at an altitude synchronised with the rotation of the Earth below. Although the satellites appear to reside in the same location in the sky at all times, there is really a round-trip delay of a bit more than a half-second, and this latency can cause frustration for those trying to communicate in real time. Deploying multiple satellites to overlap coverage can prevent latency.

In December of 2016, NASA launched a constellation of micro-satellites from an airliner. The constellation, which is called the Cyclone Global Navigation Satellite System, measures surface winds at the centre of tropical cyclones, hurricanes and typhoons. Other uses for satellite constellations include telecommunications, tracking and location awareness systems, government and military monitoring and espionage. Examples include direct broadcast satellite (DBS) systems, Global Positioning Systems (GPS), the Russian Federation’s Global Navigation Satellite System (GLONASS) and satellite-based Lidar.

Satellite constellations are also being used for broadband Internet and satellite phone and cellular phone networks. Although the performance doesn’t yet match that of contemporary landlines, in situations where satellite-based networking may be the only option for those without access to terrestrial wired or wireless services, the compromises involved can be more than tolerable.

OneWeb, Starlink and Kuiper

The space rush for the deployment of satellite constellations kicks off this year with SpaceX on the front line. These Low Earth Orbit (LEO) gears should eventually give access to the global network to all the inhabitants of the planet, even in the most remote areas. The race for funding is now engaged. The projects managed to attract investors despite doubts about the economic model. Such constellations can be considered to be a number of satellites with coordinated ground coverage, operating together under shared control, synchronised so that they overlap well in coverage, the period in which a satellite or other spacecraft is visible above the local horizon.

The amounts at stake are colossal. Some fifty constellation projects are identified around the world. Their unit cost? Between five and ten billion American dollars, depending on their size and sophistication. Either between two hundred and fifty and five hundred billion dollars to find to realise all those projects… The race for the financing is launched between the promoters of these fleets of small satellites placed in Low Earth Orbit (LEO), whose ambition is to connect Earthmen deprived of Internet broadband (between three and four billion people on the planet), at very competitive rates.

After OneWeb in February 2019, Starlink, the constellation of SpaceX founder Elon Musk, begins its career in orbit while Kuiper, the future constellation of Jeff Bezos, the founder of Amazon and Blue Origin, is scheduled to hit the scene in the early 2020s. Five leading investors participated in these fundraisers, the most involved is Google. These three constellations managed to attract investors despite doubts about the economic model. In total, Elon Musk has raised two and a half billion American dollars since 2016; this, without taking into account the last operation in progress, launched in April 2019, for a total of five hundred million American dollars. In 2015, Elon Musk explained that the profits of Starlink, which he hoped for thirty billion American dollars of turnover from 2025, would be used to finance his future Starship, the fully-reusable second stage and spaceship of the SpaceX BFR rocket destined to join the Moon and Mars.

Launched in 2014 by Greg Wyler, OneWeb raised three point four billion American dollars. After the successful launch of the first six satellites developed with Airbus in early 2019, the start-up completed, in March, a record-breaking second round, at one point twenty-five billion American dollars, with the Japanese SoftBank Corp., the Mexican Grupo Salinas, the American Qualcomm and Rwanda. As for Kuiper, it benefits from the power of Jeff Bezos, the richest man in the world.

For investors, satellite constellations are a risky bet. At least in the short term. All will not survive “Space Darwinism”. Once the technical problems are overcome, how will they make money with customers, albeit many, but with limited means. Beyond the slogan “Internet for all”, the constellations target more lucrative markets (aviation, cruise lines, governments, companies…). They are part of the long term and complementary to the existing ecosystem. They bet that the demand for connectivity will grow so much that there will be room for a satellite infrastructure. Google, for example, plans to rely on Starlink to launch a streaming video game offer. Amazon is counting on Kuiper to “recruit” new individual and business customers. Amazon has an agreement with Lockheed Martin, which will provide the ground segment. The satellite data receiving antennas will be close to the Amazon data centres that will receive them. The group will be able to directly offer data management and analysis services to its cloud customers.

Space Legal Issues

Some Space Legal Issues might arise from the development of those satellite constellations. The first one is access to Earth orbits. The second one is Space Traffic Management.

Earth orbits

An orbit is the curved path through which objects in space move around a planet or a star. The 1967 Treaty’s regime and customary law enshrine the principle of non-appropriation and freedom of access to orbital positions. Space Law and International Telecommunication Laws combined to protect this use against any interference. The majority of space-launched objects are satellites that are launched in Earth’s orbit (a very small part of space objects – scientific objects for space exploration – are launched into outer space beyond terrestrial orbits). It is important to precise that an orbit does not exist: satellites describe orbits by obeying the general laws of universal attraction. Depending on the launching techniques and parameters, the orbital trajectory of a satellite may vary. Sun-synchronous satellites fly over a given location constantly at the same time in local civil time: they are used for remote sensing, meteorology or the study of the atmosphere. Geostationary satellites are placed in a very high orbit; they give an impression of immobility because they remain permanently at the same vertical point of a terrestrial point (they are mainly used for telecommunications and television broadcasting).

A geocentric orbit or Earth orbit involves any object orbiting Planet Earth, such as the Moon or artificial satellites. Geocentric (having the Earth as its centre) orbits are organised as follow:

1) Low Earth orbit (LEO): geocentric orbits with altitudes (the height of an object above the average surface of the Earth’s oceans) from 100 to 2 000 kilometres. Satellites in LEO have a small momentary field of view, only able to observe and communicate with a fraction of the Earth at a time, meaning a network or constellation of satellites is required in order to provide continuous coverage. Satellites in lower regions of LEO also suffer from fast orbital decay (in orbital mechanics, decay is a gradual decrease of the distance between two orbiting bodies at their closest approach, the periapsis, over many orbital periods), requiring either periodic reboosting to maintain a stable orbit, or launching replacement satellites when old ones re-enter.

2) Medium Earth orbit (MEO), also known as an intermediate circular orbit: geocentric orbits ranging in altitude from 2 000 kilometres to just below geosynchronous orbit at 35 786 kilometres. The most common use for satellites in this region is for navigation, communication, and geodetic/space environment science. The most common altitude is approximately 20 000 kilometres which yields an orbital period of twelve hours.

3) Geosynchronous orbit (GSO) and geostationary orbit (GEO) are orbits around Earth at an altitude of 35 786 kilometres matching Earth’s sidereal rotation period. All geosynchronous and geostationary orbits have a semi-major axis of 42 164 kilometres. A geostationary orbit stays exactly above the equator, whereas a geosynchronous orbit may swing north and south to cover more of the Earth’s surface. Communications satellites and weather satellites are often placed in geostationary orbits, so that the satellite antennae (located on Earth) that communicate with them do not have to rotate to track them, but can be pointed permanently at the position in the sky where the satellites are located.

4) High Earth orbit: geocentric orbits above the altitude of 35 786 kilometres.

The nature of activities undertaken in space is such that cooperation is essential: satellites can’t be launched without different ground stations following the trajectory of the launcher, the continuous observation of the Sun can’t be realised (considering the rotation of Earth) without a cooperation between multiple operators, and telecommunications can be exchanged audibly only if there is an agreement on the distribution of frequencies; space technology therefore necessarily passes through a fairly elaborated cooperation. In telecommunications, it’s the International Telecommunication Union or IUT which deals with inter-state cooperation. Telecommunication includes any transmission or reception of signs, signals, images, images, sounds or intelligence of any kind, by wire, radio, optical or other electromagnetic systems. The International Telecommunication Union, which manages space telecommunications (equitable and rational distribution of terrestrial frequencies and the specific application for geostationary orbit), is a specialised agency of the United Nations (UN) that is responsible for issues that concern information and communication technologies; it is the oldest among all the fifteen specialised agencies of UN. The ITU coordinates the shared global use of the radio spectrum, promotes international cooperation in assigning satellite orbits, works to improve telecommunication infrastructure in the developing world, and assists in the development and coordination of worldwide technical standards. ITU’s mission is to harmonise the development of telecommunications resources so as to make the best use of the technologies they offer, particularly in space; it recognises the sovereign right of each State to regulate its telecommunications.

Near-Earth space is formed of different orbital layers. Terrestrial orbits are limited common resources and inherently repugnant to any appropriation: they are not property in the sense of law. Orbits and frequencies are res communis (a Latin term derived from Roman law that preceded today’s concepts of the commons and common heritage of mankind; it has relevance in international law and common law). It’s the first-come, first-served principle that applies to orbital positioning, which without any formal acquisition of sovereignty, records a promptness behaviour to which it grants an exclusive grabbing effect of the space concerned. Geostationary orbit is a limited but permanent resource: this de facto appropriation by the first-comers – the developed countries – of the orbit and the frequencies is protected by Space Law and the International Telecommunications Law. The challenge by developing countries of grabbing these resources is therefore unjustified on the basis of existing law. Denying new entrants geostationary-access or making access more difficult does not constitute appropriation; it simply results from the traditional system of distribution of access rights. The practice of developed States is based on free access and priority given to the first satellites placed in geostationary orbit.

The need for Space Traffic Management

Since the late 1990s, technology advancements have enabled high-functioning satellites to be much smaller and lighter. Coupled with similar improvements in launch technology, large numbers of new operators have gained access to space and have been placing an ever-growing number of satellites into orbit. Some of these new operators do not have extensive experience in space and are employing novel methods of satellite design, construction, and operation which could potentially lower levels of satellite reliability and increase the possibility of failures.

Space traffic management is defined by the International Academy of Astronautics (IAA) as “the set of technical and regulatory provisions for promoting safe access into outer space, operations in outer space and return from outer space to Earth free from physical or radio-frequency interference”. In the United States of America, President Donald Trump signed Space Policy Directive-3 on June 18, 2018, which defined Space Traffic Management (STM) as “the planning, coordination, and on-orbit synchronization of activities to enhance the safety, stability, and sustainability of operations in the space environment”.

Space traffic management is the classification of services designed to help satellite operators avoid physical or operational conflicts. Commercial, civil, academic, and international entities all contribute to the development of procedures to ensure universal spaceflight safety by creating actionable predictions, early warnings, and sound avoidance manoeuvres. Solutions to the space traffic problem include minimising growth in the number of future objects and maximising the accuracy of orbital predictions. As the number of objects orbiting Earth grows, the question of who should be responsible for space traffic management becomes more important. The number of objects orbiting Earth has grown substantially in recent years. This increase is already straining the existing systems for tracking and managing space traffic, and the problem is only getting worse.

New Space activity includes large LEO constellations, or LLCs, and small satellites such as CubeSats. It will radically change space operations and, combined with new sensor systems, will necessitate changes in the way Space Traffic Management is conducted. For example, there are multiple constellations each with thousands of satellites being proposed to provide global broadband Internet services. A common feature of these LLCs is their concentration of satellites into small altitude regions in the Low Earth Orbit (LEO) regime, where orbits are lower than two thousand kilometres above the Earth’s surface. They can therefore pose a collision risk to other satellites residing either nearby or passing through such altitudes. Similarly, the disposal of these satellites when they reach end-of-mission life poses a potential risk to other satellites at altitudes away from the operational LLC altitudes. New sensor systems such as the Space Fence are also expected to add large numbers of smaller, previously untracked objects to the US Space Surveillance Network (SSN) catalog. As a result, both the constellation owners and other LEO operators will have to deal with increasing numbers of both collisions and conjunction alerts. Any Space Traffic Management (STM) system will have to take this New Space activity, satellite constellations, into consideration.