The Earth orbits

Let’s study, for this new Space Law article on Space Legal Issues, the Earth orbits and the legal situation concerning the 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).

List of the different Earth orbits

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.

Lagrangian point and Earth orbits

In celestial mechanics, Lagrangian points are points near two large bodies in orbit where a smaller object will maintain its position relative to the large orbiting bodies. At other locations, a small object would go into its own orbit around one of the large bodies, but at the Lagrangian points, the gravitational forces of the two large bodies – the centripetal force of orbital motion and the Coriolis acceleration – all match up in a way that cause the small object to maintain a stable or nearly stable position relative to the large bodies; the interaction of the forces creates a point of equilibrium where space objects may be parked to make observations. There are five such points. These points were named after Joseph-Louis Lagrange (25 January 1736 – 10 April 1813), an Enlightenment Era mathematician and astronomer who wrote about them in a 1772 paper concerning what he called the three-body problem; they are sometimes called libration points. Because of the stability of these points, dust and asteroids tend to accumulate in these regions.

The International Telecommunication Union (ITU)

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 realized (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 specialized 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.

The freedom of use of Earth orbits and frequencies

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 geostationary orbit is part of outer space and, as such, the customary principle of non-appropriation and the 1967 Space Treaty apply to it. The equatorial countries have claimed sovereignty, then preferential rights over this space. These claims are contrary to the 1967 Treaty and customary law. However, they testify to the concern of the equatorial countries, shared by developing countries, in the face of saturation and seizure of geostationary positions by developed countries. The regime of res communis of outer space in Space Law (free access and non-appropriation) does not meet the demand of the developing countries that their possibilities of future access to the geostationary orbit and associated radio frequencies are guaranteed. New rules appear necessary and have been envisaged to ensure the access of all States to these positions and frequencies.