Orbital Tugs: The Urgently-Needed "Keystone Species" of the Low-Orbit Ecosystem
title: "Orbital Tugs: The Urgently-Needed 'Keystone Species' of the Low-Orbit Ecosystem" date: "2026-09-15" author: "Zhigeng" channel: "space" excerpt: "Looking at near-Earth orbit through an ecological lens: a low-orbit ecosystem has already formed, composed of producers, consumers, decomposers, and the runaway 'invasive species' of space debris—and the orbital tug (OTV) is precisely the keystone species that can rebuild its order. Space is not a frontier to be conquered, but an ecosystem to coexist with." tags: [] readTime: 18
I. When Space Becomes an "Ecosystem": A Neglected Perspective
When we discuss space issues, we usually use engineering language: orbital parameters, propellant, collision probability, the Kessler effect…… But today, I want to switch perspectives—to use the language of ecology to redescribe everything happening above our heads.
When Sputnik 1, the first artificial satellite, entered orbit in 1957, near-Earth space was still just an "experimental field"; when the Hubble Telescope launched in 1990, it was a "research platform"; when Starlink debuted in 2019, it had already become a "commercial development zone"; and today, with nearly 15,000 active satellites and over 54,000 trackable space objects, near-Earth orbit has become an ecosystem in the process of self-evolution.
| Year | Landmark event | Number of orbital objects | Ecosystem stage |
|---|---|---|---|
| 1957 | Sputnik 1 launched | 1 | Experimental field |
| 1990 | Hubble Telescope launched | ~500 | Research platform |
| 2019 | Starlink debut | ~2,000 | Commercial development zone |
| 2026 | Nearly 15,000 active satellites | >54,000 | Quasi-ecosystem |
This ecosystem has producers (human space systems), consumers (various functional satellites), decomposers (orbital decay and atmospheric incineration), and a runaway "invasive species"—space debris. It follows laws similar to those of Earth's ecosystems: species population growth, niche competition, resource consumption and regeneration, and the "ecological disaster" (the Kessler effect) that inevitably occurs when the system falls out of balance.
II. Three Types of Species: Reconstructing the Ecological Niches of Near-Earth Orbit
If we analyze near-Earth orbit through an ecological framework, we find that three core types of species have basically taken shape here.
1. Foundational species: the "native inhabitants" and "invaders" of orbit
A "foundational species" is one that forms the basis of an ecosystem. In the ecosystem of near-Earth orbit, the foundational species are all the objects currently in orbit:
Active spacecraft: about 15,000 working satellites, including communications, navigation, remote sensing, scientific research, and other types, are the "dominant species" and main functional species of this system.
Decommissioned spacecraft: over 33,000 abandoned satellites form the system's "dead wood and humus," resources that should be repeatedly recycled.
Space debris: over 140 million fragments larger than 1 millimeter are the system's "harmful parasites," resources that need to be converted or the harmful species that need to be cleaned up.
Rocket bodies: every year, more and more upper stages of rockets are abandoned in orbit, becoming "large floating reefs," also resources that should be brought into the system's ecological cycle.
These objects together form the physical basis of the near-Earth orbit ecosystem; their density, distribution, and interactions determine the stability of the entire system. Like the trees in a tropical rainforest, they provide living space for each other and for other species, but they may also, through over-reproduction, lead to ecological disaster.
It should be noted that no matter what form of resource it is, if used improperly, it can become a scourge that damages the system.
2. Keystone species: the ecological role of orbital tugs and repair stations
In ecology, a "keystone species" is one that has a disproportionately huge impact on the entire ecosystem. Its presence or absence directly determines the structure and function of the ecosystem. For example, sea otters control the number of sea urchins, and the number of sea urchins determines the scale of the kelp forest; when sea otters disappear, the proliferation of sea urchins destroys the entire kelp forest ecosystem.
In the ecosystem of near-Earth orbit, various orbital tugs (OTV, Orbital Transfer Vehicle) are precisely such keystone species:
Orbital tugs: can capture, transfer, and deploy various orbital objects, equivalent to the "porters" and "regulators" of the ecosystem.
Servicing satellites (on-orbit servers): can provide fuel replenishment, on-orbit maintenance, fault diagnosis, and other services, the "doctors" and "nurses" of the ecosystem.
Repair stations: as proposed in the article "Space Graveyard Repair Station: A Place of Hope for Cracking the Kessler Effect" published by this account on July 1, they can dismantle, recycle, and reuse space debris—the "decomposers" and "circulatory system" of the ecosystem.
Space traffic management systems: including ground control centers and space-based monitoring platforms, the "brain" and "command center" of the ecosystem.
The absence of these keystone species is precisely the cause of the current chaos in the near-Earth orbit ecosystem. Without them, the system can only operate by the primitive law of "survival of the fittest," eventually heading toward collapse.
3. Basic producers: human space economy and industrial systems
Any ecosystem needs energy input, and humanity's space systems are the basic producers of the near-Earth orbit ecosystem:
Rocket launch capacity: equivalent to the "photosynthesis" of the ecosystem, converting ground matter and energy into orbital existence.
Space industry: manufacturing satellites, rockets, and various space facilities, the ecosystem's "nutrient supply chain."
Commercial operations: creating economic value through communications, navigation, remote sensing, and other services, providing the system with the momentum for sustainable development.
Scientific innovation: continuously exploring new technologies and applications, driving the evolution and upgrading of the ecosystem.
III. The Chaotic Status Quo: A Low-Orbit Ecology Heading Out of Control
The current near-Earth orbit ecosystem is in a state of severe chaos, mainly manifested in the following aspects:
1. Species over-reproduction: orbital crowding is approaching the critical value
According to data from the European Space Agency (ESA) and the US Space Surveillance Network (SSN), as of 2026:
| Type of orbital object | Quantity | Proportion | Collision risk |
|---|---|---|---|
| Trackable objects | 54,000 | 100% | High |
| Working satellites | 15,000 | 28% | Medium |
| Defunct satellites | 33,000 | 61% | High |
| Rocket bodies | 6,000 | 11% | Very high |
| 1–10 cm debris | 1,200,000 | - | Medium |
| <1 mm debris | 140,000,000 | - | Low but persistent |
Satellite launches surged from 250 in 2019 to 28,000 in 2025, an 11-fold increase in seven years. The density of near-Earth orbit satellites has reached 0.04 objects per thousand cubic kilometers, approaching the Kessler effect threshold (0.1 per thousand cubic kilometers). In 2025, more than 310,000 satellite collision-avoidance maneuvers were executed worldwide, of which Starlink accounted for 97%.
This exponential growth is turning near-Earth orbit into a "space parking lot," where every satellite searches for living space in the cracks.
2. Niche competition: a "law of the jungle" without rules
The current allocation of orbital resources follows the principle of "first come, first served," lacking an effective management mechanism. Frequency-orbit conflicts: multiple operators compete for the same frequency and orbital position, causing signal interference and increased collision risk; chaotic avoidance maneuvers: in 2025 Starlink executed 300,000 collision-avoidance maneuvers, and the International Space Station performed more than five avoidance maneuvers throughout the year; missing retirement mechanisms: about 60% of retired satellites have not entered graveyard orbits but continue to drift in active orbits.
This "law of the jungle" competition is consuming the system's resources and increasing the costs and risks of all participants.
3. Proliferation of invasive species: the "biological invasion" of space debris
Space debris is the "invasive species" of the near-Earth orbit ecosystem: rapid reproduction: every collision produces new fragments—the 2021 Russian anti-satellite test produced over 1,500 trackable fragments; lack of natural predators: there is currently no effective "debris cleanup mechanism," and most fragments will remain in orbit for decades or even centuries; disruption of ecological balance: a 10-centimeter fragment can destroy a satellite, while millimeter-scale debris continuously wears down spacecraft surfaces.
This invasion is turning near-Earth orbit into a "junkyard," threatening the safety of the entire space industry.
IV. The Mission of the Keystone Species: Building a Harmonious Space Ecology
As keystone species, orbital tugs shoulder the mission of building the near-Earth orbit ecosystem. Their core task is to find a suitable niche for every species in the system, enabling the whole system to develop healthily and sustainably.
1. The niche-regulation capability of orbital tugs
| Regulation dimension | Current state | Target state | Role of orbital tugs |
|---|---|---|---|
| Orbital density | 0.04/km³ | 0.02/km³ | Debris cleanup, satellite redeployment |
| Collision probability | 1/1000/yr/satellite | <1/10000/yr/satellite | Active avoidance, debris removal |
| Resource utilization | <10% | >50% | Satellite repair, resource recovery |
| System stability | Fragile | Robust | Real-time monitoring, intelligent scheduling |
2. Orbital tugs: the "regulators" of the ecosystem
The main functions of orbital tugs are space traffic management and object transfer. Active avoidance: through precise orbital prediction and maneuvering operations, avoid collisions between satellites; debris cleanup: capture and remove large space debris, reducing the "harmful species" in the system; orbital deployment: precisely deploy satellites to designated orbital positions, optimizing resource allocation; retirement handling: transfer retired satellites to graveyard orbits or guide them to burn up in the atmosphere.
Just as wolves in a forest control the number of deer, orbital tugs maintain the balance of the entire system by regulating the distribution and density of various orbital objects.
3. Repair stations: the "circulatory system" of the ecosystem
As a concept proposed in "Space Graveyard Repair Station," repair stations are the centers for the recycling of space resources. Dismantling and recycling: dismantle defunct satellites into reusable components and raw materials; repair and upgrade: provide on-orbit repair services for satellites, extending their service life; manufacturing and assembly: use recycled materials to manufacture new satellite components and facilities in orbit; fuel replenishment: provide on-orbit refueling services for satellites, improving system operating efficiency.
Repair stations convert the "waste" of the ecosystem into "resources," realizing the circular use of matter, just like the microbial decomposers of Earth's ecosystems.
4. Space traffic management systems: the "brain" of the ecosystem
A healthy ecosystem needs a "command center" to coordinate the activities of its various species, and the space traffic management system is the "brain" of the near-Earth orbit ecosystem. Real-time monitoring: track the position and status of all orbital objects; intelligent scheduling: use AI algorithms to optimize satellite orbits and maneuvering plans; rule-making: establish and enforce norms and standards for orbital use; emergency response: take rapid measures when collisions or failures occur.
This system will transform the current "disorderly competition" into "orderly collaboration," ensuring the efficient operation of the entire ecosystem.
V. Three Layers of Connection: The Ecological Chain from Earth to Deep Space
The near-Earth orbit ecosystem is not isolated; it will be part of a larger system.
1. Downward connection: the extension of Earth's ecosystem
The near-Earth orbit ecosystem directly depends on Earth's ecosystem. Resource input: all spacecraft need to obtain materials, energy, and personnel from Earth; economic support: the development of the space industry depends on the demand and investment of Earth's economic system; environmental impact: space activities produce environmental impacts such as atmospheric pollution and electromagnetic radiation; safety assurance: ground policies and legal frameworks determine the rules and boundaries of space activities.
Therefore, the healthy operation of the near-Earth orbit ecosystem is an important component of the sustainable development of Earth's ecosystem.
2. Self-balance: building a sustainable space ecology
The near-Earth orbit ecosystem needs to achieve its own balance. Resource recycling: establish effective mechanisms for the recovery and reuse of space debris; niche allocation: rationally allocate orbital and frequency resources to avoid excessive competition; population control: set standards for the handling of retired satellites and control the total number of orbital objects; diversity protection: protect the living space of scientific research satellites and special-purpose satellites.
Only by achieving self-balance can this ecosystem provide humanity with sustained services and value.
3. Upward extension: the springboard for deep-space exploration
The near-Earth orbit ecosystem is the frontier base of humanity's deep-space exploration. Lunar gateway: near-Earth orbit is a transit station to the Moon, and future lunar bases need to obtain supplies and personnel from here; Mars missions: spacecraft for Mars exploration missions need to be assembled and tested in near-Earth orbit; deep-space resource development: asteroid mining and space solar power and other deep-space activities need near-Earth orbit as their base; civilization expansion: near-Earth orbit is the first step in humanity becoming a multi-planetary species.
Therefore, protecting the stability of the near-Earth orbit ecosystem is protecting humanity's passage to deep space.
VI. Action Plan: Three Steps to Build a Harmonious Space Ecology
To build a healthy and sustainable near-Earth orbit ecosystem, we need to take the following actions:
Step One (2026–2030): Establish basic rules and key facilities; formulate international standards
Establish globally unified space traffic management rules and standards for handling retired satellites. This work is among the important tasks underway in international space organizations, and here I suggest incorporating the thinking of ecosystems and "keystone species."
Deploy orbital tugs: launch the first batch of orbital tugs, beginning to clean up large space debris and carry out space traffic management tasks. Commercial space companies are already working on this, but progress has been difficult; here I suggest that national space agencies attach importance to it and give greater support.
Build experimental repair stations: deploy small repair stations in near-Earth orbit to verify space resource recovery and reuse technologies. Some companies are currently contemplating this work, but because of the large engineering scale and the difficulty of forming a commercial closed loop, it is stalled.
Develop intelligent monitoring systems: establish a globally covered network for monitoring space objects, realizing real-time tracking and early warning. This work is currently in progress, and the data cited at the beginning of this article comes from these systems. Mentioning it here is only to emphasize that it is an important part of the ecosystem envisioned in this article, and to suggest endowing it with more functions.
Step Two (2030–2035): Realize resource recycling and system balance; scale up the repair-station network
Deploy multiple repair stations in near-Earth orbit and graveyard orbits, forming a resource-recycling network and commercializing it.
Orbital services: develop commercial services such as orbital tugs, fuel replenishment, and on-orbit maintenance, establishing an ecosystem.
Compensation mechanisms: give economic incentives to enterprises that clean up space debris and recover resources.
Limit total orbital objects: establish a satellite launch quota system to control the growth rate of orbital objects.
Step Three (2035–2040): Move toward deep space and civilizational upgrade; establish a lunar base
Mutually support the near-Earth orbit base and build a sustainable lunar base.
Develop deep-space resources: carry out deep-space resource development activities such as asteroid mining and space solar power, but the principle is that what is mined in space is used in space, and what is mined on the ground is used on the ground; unless necessary, do not increase large-scale round-trip transport (for the reasons, see "Space Graveyard Repair Station").
Prepare for interstellar navigation: develop a new generation of crewed spacecraft to prepare for Mars missions and deeper space exploration.
At the same time, space civilization governance: establish a global space governance institution and formulate ethical and legal frameworks for human space activities.
VII. The Choice of Civilization: From "Conquering Space" to "Coexisting with Space"
From the moment humanity first looked up at the stars, it implied that space would inevitably become an object of future "conquest." But today, when humanity has deployed over ten thousand satellites in orbit, and the risk of the Kessler effect draws ever nearer, we need to change our thinking: space is not a frontier to be conquered, but an ecosystem with which we need to coexist.
As the keystone species of this ecosystem, the mission of the "orbital tug" is not to "clean up garbage," but to establish a new relationship between humanity and the heavens—a harmonious, balanced, and sustainable relationship.
This relationship requires us to: respect natural laws—including physical laws and ecological laws; take responsibility—be responsible for every object we send into space and everything produced in space; pursue balance—find a balance between development and protection, between utilization and regeneration; and develop together—through global cooperation in responding to the challenges of space governance.
VIII. Conclusion: The Awakening of the Space Ecosystem
The formation of the near-Earth orbit ecosystem marks the entry of humanity's space enterprise into a new stage. The core challenge of this stage is no longer "how to enter space," but "how to survive and develop sustainably in space."
As the keystone species of the near-Earth space ecosystem, orbital tugs can play a core role in this transformation. They are not only a technological solution but also a shift in civilizational concepts—from "conquest" to "coexistence," from "utilization" to "circulation," from "individual competition" to "systemic harmony."
As this account wrote in "Space Graveyard Repair Station": "A graveyard repair station project started immediately is to turn garbage—this burden of civilization—into a key that unlocks the road to a new civilization." Today, this article proposes: "A network of orbital tugs deployed immediately is to turn the chaotic near-Earth orbit—this potential threat to civilization—into a sustainable space ecosystem."
Space is not a junkyard, nor a battlefield; it is the extension of human civilization and our common home. Let us use ecological wisdom to protect this space, so that humanity's space enterprise, like the tropical rainforest on Earth, flourishes and develops sustainably.