Albator Project

Context

With the rapid expansion of satellite constellations and space activity, Earth’s orbits are becoming increasingly crowded and hazardous. According to CNRS, in 2023, there were more than 36,000 objects in space larger than 10 cm – of which only a few thousands are active satellites – while an estimated 1 million objects between 1–10 cm and over 130 million smaller fragments, mostly undetectable but potentially deadly. And these numbers keep growing !

These high-speed objects—traveling at up to 28,000 km/h—pose a serious threat to operational spacecraft, future missions, and the long-term sustainability of outer space. Current passive measures are no longer sufficient to manage this growing risk. For example, a 12U satellite left at an altitude of 580 km could remain in orbit for more than 20 years before naturally deorbiting, continuing to endanger other space assets throughout that time. That’s why innovative, active space debris removal solutions are urgently needed. By safely deorbiting high-risk objects, we can help preserve the orbital environment, protect vital infrastructure, and ensure a safer future for global space operations.

Number of objects > 10cm in LEO. Credit: NASA ODPO.

Concept

The ALBATOR project continues the pioneering work of the Ion Beam Shepherd concept, advancing it toward experimental validation and mission readiness. This approach relies on an onboard ion source that expels a directed, quasi-neutral ion beam toward a target debris object. The momentum carried by the ions is transferred to the debris upon impact, generating a small but continuous force that modifies its orbit over time. A secondary propulsion system on the chaser spacecraft compensates for the reaction force, allowing for stable, contactless proximity operations. By optimizing beam collimation, thrust efficiency, and long-duration control, ALBATOR aims to demonstrate the feasibility of this method for safe and controlled de-orbiting of space debris.

Activities

Ion source development

After a preliminary study to determine key characteristics of the ion source, we will design and prototype an ion source, able to generate a suitable ion beam for debris removal.

The ion source will be based on ECR technology, relying on :

A high power microwave input to generate the plasma,
A strong magnetic field to confine the plasma and to achieve electron cyclotron resonance
A High Voltage extraction to expel the ions and generate the Ion beam

Source and plume modelling

Separate physics-based models will be developed for:

The plasma source, to understand the driving physics
The plume expansion and its interaction with nearby space debris and spacecraft surfaces

These models will later be coupled to simulate realistic de-orbiting and detumbling scenarios

Experiments and tests

The ion source prototype will be evaluated on a dedicated test bench equipped with appropriate diagnostic tools. These experiments will make it possible to measure the force exerted on various target materials, and to test different source operating modes and propellant gases, in order to optimise its effectiveness on the target.

PLASMA-MATERIAL INTERACTION

Ion beam interactions at various kinetic energies, ion species, target materials, and angles of incidence will be calculated. A simulation model will then be created to calculate torques and forces on arbitratily shaped and composed debris objects.
We will build on our expertise in momentum transfer studies of beam–target interactions (sputtering and implantation), using both force probes and simulations, to develop concrete applications for space debris removal. Within the project, we will set up a comprehensive open-source model and a corresponding database, and ensure their long-term maintenance and continued improvement. This will allow us to transfer research from a primarily academic context into practical applications. In addition, the model and data will serve as a foundation for ongoing research, doctoral and master theses, and for training the next generation of experts in space propulsion technologies.

Mission design

Taking into account all input data generated from the activities described above, dedicated software will be developed to perform orbit and attitude control, and to simulate Active Debris Removal (ADR) and detumbling mission scenarios with high fidelity.