ADAMO - High-Power Adaptive Optics for Laser Momentum Transfer

At present, there are more than 22,000 space debris objects in low Earth orbit (LEO) that are tracked and catalogued. In the same orbital regime, there are estimated to be 150 million fragments of human-created junk, all less than 1 mm in size, travelling at 8-12 km/s. This underscores the pressing need for effective solutions to address space situational awareness, tracking and imaging of space objects, space debris removal, and collision avoidance.

In recent years, several laser-based concepts for orbit modification have been proposed, including the use of pulsed lasers with high energy to perform orbit modification through laser ablation and high-power, continuous-wave lasers for debris nudging by photon pressure. In the ESA-funded project "ADAMO", Fraunhofer IOSB, Fraunhofer IOF, and HEIG-VD will develop demonstrator(s) for adaptive optics (AO) technologies, which are necessary to efficiently pre-compensate high-energy lasers in order to make laser momentum transfer (LMT) effective in LEO.

The project's key objectives are to design an AO system capable of compensating for the quickly changing wavefront distortions induced by atmospheric turbulence and telescope slew. The future system will utilise a laser guide star for high-order aberrations and sunlight reflected from debris for low-order aberrations (tip/tilt). The project will also involve the development of a demonstrator to validate the key AO system's functionalities in a controlled laboratory environment, which will be vital for de-risking the technology before deployment.

The focus lies in the development of the key components of an LMT-AO system, which include: (1) a deformable mirror (DM) for pre-compensation of the high-power (40 kW) uplink (Fraunhofer IOF), (2) a fast wavefront sensor (WFS) for accurate measurements (Fraunhofer IOSB), and (3) a control system to effectively command the DM (HEIG-VD).