Space debris

Starting in early 2021, IRGC will start a new project on managing space debris risk for governing risks to space sustainability, in collaboration with the eSpace Centre at EPFL.

The problem

Space debris refers to anything left in space by humans. The Inter-Agency Space Debris Coordination Committee (IADC) defines space debris as: “all man-made objects including fragments and elements thereof, in Earth orbit or re-entering the atmosphere, that are non-functional“. These items can be as large as defunct satellites or as small as a paint chip from a rocket.

There are currently almost one million of these uncontrollable debris objects of more than 1 cm, each bringing with it the danger of functional damage to operational satellites. This problem has been studied and discussed for the past 30 years but remains a source of concern, especially as the amount is rising due to collisions of pieces of space debris with one another. This causes increasing risk exposure to a growing number of operating satellites. A cascading effect could be triggered if the number of objects in orbit increases past a tipping point, after which collisions between debris and with operational satellites could generate more debris than the natural decay process can eliminate, thus rendering some orbits unusable for space activities.

While the issue of space debris might not seem dire to those of us on the ground, the collapse of communication satellites can fundamentally disrupt the availability of vital services provided by these satellites, such as GPS and internet.

Risk assessment

Estimating the risks posed by space debris is a complicated undertaking due to:

  • the complexity of the models used to predict the risk and consequences of collision,
  • uncertainty regarding the future decisions of space actors and
  • ambiguity in the way that various actors in the space economy behave when confronted by the risk.

Risk management

Some options for space debris mitigation and remediation do exist but are costly, and few are technically ready. Their implementation requires cooperation between actors, willingness to share costs and a real motivation to act. Such motivation is currently missing, due to a lack of international regulation and liability, lack of incentives for collective action, and limited risk of reputational damage. Some regulations and guidelines exist, but overall response strategies have thus far been too modest. There is also a general perception that the benefits of services provided by satellites largely exceed the costs incurred in their operation. But how true is this? The problem of space debris is marked by the possibility of catastrophic chain interactions, making collaboration in risk governance a critical priority.