“Our orbital environment is a natural resource. Just as we need to protect our rivers, forests and oceans on Earth, we believe our orbits need to be monitored and maintained in order to be sustainable”. When a valuable, naturally-occurring resource, is difficult to substitute, its preservation is of prime importance.
Our specific Earth orbits, where satellites carry out specific missions (Earth observation missions in Sun-synchronous orbits, positioning in medium-Earth orbits, telecommunication satellites in Geostationary orbit), are precisely such natural resources that are staggeringly cost-intensive and, in certain cases, improbable to substitute. This makes Earth orbits limited natural resources that require preservation.
The orbital environment
The orbital environment refers to all orbits used by space objects since the 1950s. An orbit is the curved path through which objects in space move around a planet or a star. The 1967 Outer Space Treaty’s regime enshrines 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 the 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.
What is a natural resource?
Natural resources are components that exist in the world without the input of humans. These natural resources are diverse, ranging from renewable resources to non-renewable resources, living to non-living resources, tangible to intangible resources. Natural resources are essential to the survival of humans and all other living organisms. All the products in the world use natural resources as their basic component, which may be water, air, natural chemicals or energy. The high demand for natural resources around the world has led to their rapid depletion.
Natural resources could be classified into different categories, such as renewable and non-renewable resources, biotic and abiotic resources, and stock resources. Renewable resources refer to resources that can naturally regenerate after use. They include resources such as wind, water, natural vegetation, solar energy, and animals. These resources exist in nature in abundance. There is little concern about depleting renewable resources because their rate of production exceeds the rate of human consumption. Conservationists throughout the world advocate for the use of renewable resources, because they are readily available and less costly to the environment.
Non-renewable resources are components that take too long to replenish after use or exist in limited quantities. Non-renewable resources include products such as crude oil, precious metals, minerals, and rocks. Some endangered animals are also classified as non-renewable resources because their mortality rate is much higher than their reproduction rate. These non-renewable resources need to be protected and to be used responsibly to stop their depletion.
Biotic natural resources refer to living resources that exist naturally in the environment. Such resources include forests, wildlife, and fossil fuels, which are all listed as biotic natural resources. Non-biotic natural resources are natural products in the environment that are non-living. These resources include water, rocks, metals, and minerals among many others. The world has numerous resources some of which are yet to be exploited. Humans lack the skills and technology to extract and use some of the naturally occurring resources, like rare gases and some radioactive materials. As a result, these resources are classified as stock resources to be utilised in the future.
Most natural resources exist in limited quantities. Unfortunately, various factors have led to the exploitation of these resources. Some of the components are at the risk of depletion. Environmental pollution, high population, uncontrolled development, climate change, and modern lifestyles are some of the threats to natural resources. Is there an orbital pollution? What about space debris?
Is the orbital environment a natural resource?
Is therefore the orbital environment a natural resource? The way we perceive outer space today makes it inherently difficult to imagine that anything in this vast expanse might be limited in nature, or that we might run out of it at some point in time. But as they say – all good things must come to an end, and have not Earth orbits been a boon to our spacecraft orbiting Earth since the 1950s?
From the time of the first space missions, certain Earth orbits have been invaluable for communication, positioning and surveillance purposes – necessities that we cannot imagine procuring any other way today. For instance, imagine conducting surveillance without space assets: it would require thousands of airplanes flying in the sky to do what a couple of satellites manage today. Satellites can be cost-efficient, time-efficient, reliable, and provide a higher productivity. A win-win system for the entire globe.
Now imagine losing this win-win situation. Imagine an altitude shell through which satellites revolve around Earth constantly, collecting and relaying essential data. What happens when the traffic in these shells increases to the point of congestion, like a traffic jam on a highway? Or when the safe minimum distance between satellites travelling through Earth orbits is compromised? Undoubtedly, there will be collisions, like accidents on a freeway – only in outer space there is no emergency response system to go and clean up the damaged spacecraft from busy orbits and let the rest of the traffic continue smoothly. Therefore, a single collision leads to further threats of collision – what we in the space sector call high-risk conjunction warnings. It is as they say: “one event in space has consequences for everyone”.
When a valuable, naturally-occurring resource, is difficult to substitute, its preservation is of prime importance. Our specific Earth orbits, where satellites carry out specific missions (Earth observation missions in Sun-synchronous orbits, positioning in medium-Earth orbits, telecommunication satellites in Geostationary orbit), are precisely such natural resources that are staggeringly cost-intensive and, in certain cases, improbable to substitute. This makes Earth orbits limited natural resources that require preservation. We need to be sure that Earth orbits are managed efficiently and sustainably by making sure that all spacefarers follow the identified actions. This should be facilitated by developing and providing the required technology to the spacefarers.
As space is not the domain of any one country or international entity, both domestic and international regulations need to be implemented and enforced. We see that this is beginning to happen. The United States of America, Japan and European countries are all considering regulations to limit future debris, and even to remove current debris. Additionally, international organisations are discussing standards and policies that will lead to debris removal, and higher future reliability of satellites. Creating and enforcing regulations in outer space at an international level takes a lot of time, effort and patience; let’s hope that in several years, space debris removal will become routine work, much like trash collection or roadside car service here on Earth. This is what can be said concerning the orbital environment.