Snapshot of a simulated satellite strike. Credit: ESA/Fraunhofer Institute for High-Speed Dynamics.

The European Space Agency (ESA) has simulated a satellite collision as part of a project that seeks to better understand the consequences of the collisions and the formation of space debris.

Under the project, ESA conducted two different kinds of software simulations, including one at Germany’s Fraunhofer Institute for High-Speed Dynamics. The second simulation was carried out by a consortium led by the Center for Studies and Activities for Space at Italy’s University of Padua.

The first approach depends on an advanced numerical method to simulate the deformation and fragmentation processes in a collision.

Represented by a ‘finite element mesh’, the colliding items are modelled with realistic structural and mechanical properties.

“We need to have this understanding because we are currently working on expensive debris mitigation strategies based on our understanding of debris behaviour.”

The ‘finite element mesh’ is converted into separate particles as the satellites fragment, forming a simulation of their structural response to the collision. This also generates the debris, which is monitored as it evolves over time.

In the second approach, the spacecraft is treated as a structure of larger elements, including panels, payload, propellant tanks or solar arrays, attached together with physical links.

When the collision transfers energy, these links break up and the elements are fragmented.

According to ESA, when operating at material and component levels, these two types of simulation should give new insight into the underlying physics of collisions.

When these simulations replicate observed reality, they are expected to be used to reproduce full impacts of 500kg-scale satellites.

ESA Space Debris Office representative Holger Krag said: “We need to have this understanding because we are currently working on expensive debris mitigation strategies based on our understanding of debris behaviour.

“We’re projecting the evolution of the debris environment up to 200 years ahead.”

So far, four satellites collisions have taken place in the history of spaceflight industry, but the figure is expected to increase in the future.