Expert Speak Space Tracker
Published on Oct 17, 2021
As Near-Earth orbital space gets more crowded, it is imperative that states should come to a more comprehensive agreement to regulate it
Crowded outer space: Can a global Space Traffic Management (STM) be a reality? 

Near-Earth orbital space is a complex system and a finite resource that is geopolitically and commercially contested, and is in dire need of environmental protection. As a complex system, the elements that comprise it are not completely known and are intrinsically difficult to model due to, inter alia, unknown interdependencies, competitions amongst participants, and non-linear relationships between individual participants and the environment itself.

Various international space law instruments, such as the Outer Space Treaty of 1967, promote free and unhindered use of space for peaceful purposes, while avoiding harmful interference. The last two are not rigorously defined; and thus, are left to wide interpretation and implementation. Although there are no titles or deeds for orbital space, there is a finite carrying capacity to any given orbital highway and, thus, whoever takes this capacity first, wins. This has led to a commercial space race for orbital settlement and occupation. The space resource utilisation from States has led to some geopolitical saber-rattling by key space actors such as the United States (US), Russia, and China, and is manifesting as an arms race in outer space, with escalatory language and apparent behaviours. The principal issue regarding space security is the ability to predict or identify a threat. A threat could be identified on the basis of the following three ingredients: Opportunity, capability, and intent to cause harm. Opportunity to cause harm can generally be measured and assessed with sensors and astrodynamics. Capability is more challenging because it’s not about the physics but the hardware and payloads as well as the physical traits of the satellite in question.

Although there are no titles or deeds for orbital space, there is a finite carrying capacity to any given orbital highway and, thus, whoever takes this capacity first, wins.

The most difficult ingredient to measure is intent as no sensor can determine this. As a consequence, intent has the largest uncertainty. Rudolf Emil Kálmán, co-inventor of the Kalman filter, once correctly stated, “Uncertain data cannot provide exact models unless prejudice is ascribed in order to remove the inherent uncertainty”. Given the fact that in space, we have so-called dual-use technology (to wit, many objects have the opportunity and capability to cause harm) because we don’t know the intent, we simply apply prejudice and assume ill-intent in the presence of our ignorance. This is not a behaviour that leads toward harmonising space activities or establishing a sustainable environment. When an increasing number of space actors default to assuming the very worst in others, the resultant actions are surely going to be detrimental to the whole.

This underscores the need to develop and have wide-spread implementation of protocols and practices that address the intent aspect of space operations and activities. Coordination and planning of orbital manoeuvres, repositioning, and activities can serve as transparency and confidence building measures (TCMBs) that can help provide evidence which rejects the Null Hypothesis that other space objects are intending to harm their assets and capabilities. Moreover, other space security-related practices that could be helpful would be the cross-referencing of databases and registries as well as the mutual monitoring and assessment of the space activities of the participants sharing the common space domain.

When an increasing number of space actors default to assuming the very worst in others, the resultant actions are surely going to be detrimental to the whole.

Regarding the environmental protection of the  near-earth space, there is a need for a definition of a Space Traffic Footprint (STF) that can be loosely understood as the burden that any anthropogenic space object poses on the safety and sustainability of any other. To illustrate, when a new driver has taken up driving, he becomes a burden to all pedestrians and other drivers. Even if they know and can exactly predict his actions, they must account for his existence in calculating their own safety risk and posture. This accounting constitutes a burden and is thus a non-zero footprint. The STF will likely need to be a statistical index composed of composite indicators related to, inter alia, the ASO size, shape, ability to be maneuvered, design for demise, trackability, etc.

Along with the STF, there is a need for the definition of orbital carrying capacity, which can be understood as being exceeded when our decisions and actions can no longer prevent the loss, disruption, or degradation of space services and capabilities past some agreed-to threshold. Once a definition and application of STF and Orbital Carrying Capacity can be set, then there will be a quantifiable mechanism upon which to jointly manage and coordinate space traffic and activities. In fact, these sustainability metrics will allow for space insurance companies to have a role in managing space traffic through premiums and, perhaps, penalties. Moreover, an active debris removal marketplace would be able to exist and be sustained because there would be a reproducible and consistent way to quantify the benefit and impact, environmental and even financial, of removing any given ASO from the population.

Once a definition and application of STF and Orbital Carrying Capacity can be set, then there will be a quantifiable mechanism upon which to jointly manage and coordinate space traffic and activities.

Maritime salvage laws—contractual and pure—could be applied to near-earth space. Contractual salvage laws for a company under the jurisdiction of the launching state(s) associated with a given ASO could be pursued under active debris removal. For those ASOs that are tracked and catalogued but have no launching state associated with them, pure salvage laws could be pursued whereby an entity without prior arrangement could be reimbursed for successfully removing some measurable quantity of STF from an orbit and, thus, provide carrying capacity back to it.

To be sure, none of these proposed activities or mechanisms will be easy to develop or implement, but there is precedence in other domains of their successes and lessons learnt that we can use to avoid predictable pitfalls along the way. Near-earth space is depending on us to make this so.

The views expressed above belong to the author(s). ORF research and analyses now available on Telegram! Click here to access our curated content — blogs, longforms and interviews.

Contributor

Moriba Kemessia Jah

Moriba Kemessia Jah

Moriba Kemessia Jah is an American space scientist and aerospace engineer known for his contributions to orbit determination and prediction especially as related to space ...

Read More +