Laser satellite communications enable high-speed and secure internet, connected objects and handling of a large amount of data. The objective of ESA’s CREOLA (Consolidation and REfinement of Optical Link Architectures) project, which is primed by Airbus Netherlands, is to design, build and test configurations for an Optical Ground Station (OGS). Serving as the terrestrial endpoint for the transmission and reception of optical signals to and from satellites, an OGS plays a critical role in laser satellite communications.

Key findings of the In-Orbit Demonstration 

In May 2024, Airbus NL’s CREOLA Demonstration established a world-first, 9 Gbit/s class, optical downlink from GEO and tested a bi-static, stationary OGS architecture under genuine operational conditions. From an architectural perspective, this now serves as a blueprint for our future feederlink OGS products, with that opening up an even higher, new domain of at least 100 Gbit/s line-rate per optical wavelength between space and ground. This is an important prerequisite to aggregate Tbit/s class feederlinks for commercial use cases.

To achieve the links, our LightHouse beacon prototypes blazed the initial trail through the atmosphere that allowed the on-board TELEO terminal to find our OGS and get the needed lines of sight, and locked robustly between both nodes of the link. That stable uplink allowed uninterrupted communications between space and ground during the entire maximum period at full rate. Also, optical high-speed telemetry was sent from the TELEO terminal onboard of the BADR-8 satellite to our OGS receiver. 

The following key objectives have been achieved:

1. Demonstrate robust and reliable pointing, acquisition and tracking during variable atmospheric conditions
   This is an important basis, required for any kind of space-to-ground lasercom links, but especially for optical feederlinks that require very high link availability. It includes adaptive optics correction on the return link from space, which then serves as a direct input to adaptive pre-compensation on a forward communications link toward space.
2. Carry out a bi-directional space-ground-link validation 
   A space segment’s pointing accuracy impacts performance measurements related to delivered power at ground segment, and vice versa. During the space-ground-link validation, influences from the space node must be separated from both the turbulent atmospheric channel and the ground node. Space terminal measurement data is received via high-rate telemetry received on the optical downlink. Results from that validation allows for optimising the design of the future OGS product, based on genuine operations.
3. Validate atmospheric model predictions by comparing measured with expected performances
   This required measuring temporal and amplitude characteristics of optical up- and downlink signals for later evaluation. Direct measurements of turbulence key parameters at high temporal resolution along line-of-sight to TELEO support a retro-fitting of the initial atmospheric profiles used for our predictions. Evaluations use our proprietary atmospheric communications software toolbox that supports system designers by modelling dynamic atmospheric channel transmission for up- and downlinks.

Applications

There are three main types of applications for this type of Optical Ground Station:

• Military Satellite Communications: Optical ground stations are crucial for military satellite communications due to their ability to provide secure and reliable data transmission with a very low probability of interception.
• Feeder Links for Satellite Communications: Optical ground stations serve as feeder links for satellite communications by establishing high-speed data links between satellites and ground stations. These stations facilitate the transfer of data between satellites in orbit and terrestrial communication networks, supporting various applications such as broadcasting, internet services, and remote sensing.
• Data-Cloud Migration: Optical ground stations will be increasingly be utilised in data-cloud migration processes. They enable the transfer of large volumes of data between data centers and cloud storage facilities through high-speed optical communication links. This facilitates the migration of data and applications to cloud platforms, offering scalability, flexibility, and cost-effectiveness to businesses and organisations.

Testimonials

“ESA is proud to be working with our industry partners, led by Airbus Netherlands, to be playing a critical role in the future of laser satellite communications.”, said Harald Hauschildt, Head of ESA’s Optical and Quantum Communications Office. “By developing these capabilities today, via CREOLA and other ESA activities, we are ensuring Europe continues its technological leadership and industrial competitiveness on the global stage.”