08 Jul Satellite laser communication in series production
Fast and secure data exchange – even in remote areas: this is the promise of satellite-based laser communication. Europe wants to become independent of providers and suppliers from abroad in the field of laser communication. Technological sovereignty is the goal, especially in critical infrastructures such as security and civil protection.
With its ScyLight (Secure and Laser Communication Technology) program, the European Space Agency (ESA) is therefore supporting European research institutions and companies. One of the companies implementing a development project as part of the ScyLight program is Tesat. The company, based in Baden-Württemberg, has experience in satellite communication and has also been building laser communication systems for many years, including the SCOT135 system. This system is a scalable optical communication terminal that has been specially developed for use in medium earth orbit (MEO) and geostationary earth orbit (GEO).
Schematic representation of a network for laser communication. The telescope from Jena is used for the Inter-Satellite Optical Link. Image: Fraunhofer IOF
Technology large-scale production
Researchers from Jena have spent three years developing a space-robust transmitting and receiving telescope for this laser terminal, which – unlike science-oriented telescopes, for example – can be manufactured not only in small quantities, but in series. “Our aim was to develop a robust and cost-effective series product,” explains Dr. Henrik von Lukowicz, the responsible project manager and head of the Optical and Mechanical System Design department at the Fraunhofer Institute for Applied Optics and Precision Engineering IOF. “For systems that are to be manufactured in large quantities, every hour of production time is ultimately important.”
With the help of the telescope developed in Jena, the SCOT135 system is expected to achieve a bandwidth of up to 100 Gbit/s and bridge distances of up to 80,000 km. “This is new in combination with terminals, which are built in large numbers and will eventually be linked to form an inter-satellite network,” says von Lukowicz. “We have developed a universally deployable telescope that is both a transmitter and receiver unit.”
Transmitting and receiving telescope developed at Fraunhofer IOF for the SCOT135 laser terminal. Image: Fraunhofer IOF
Challenging conditions in space
When used in space, the telescope must also be able to withstand the environmental stresses there, as well as the stresses caused by the operation of the system itself: “Relatively high laser powers are used in laser communication systems. Up to 50 watts are used here. For a space telescope, this is a relatively high amount of power that propagates through the system,” explains von Lukowicz. “This leads to heat build-up, which can cause changes to the optics. But of course the performance of the system must not be impaired as a result. Thermal management was therefore a particularly important aspect of our design.”
In addition to thermal regulation, a wide range of expertise from the Fraunhofer IOF was incorporated into the design development, based on years of experience with space projects at the institute. “This involves a wide range of issues, such as how to manufacture particularly lightweight components for space flights, methods for the robust adjustment of components and the finest structuring of the optics for precise performance,” explains von Lukowicz. “We have combined many of our skills and capabilities for this in this telescope.”
Fraunhofer IOF spin-off takes over production
The design of the telescope was developed by researchers at the Fraunhofer IOF in Jena. The new space company Spaceoptix, a Fraunhofer IOF spin-off, is responsible for production at the Isseroda site in Thuringia. Spaceoptix has already manufactured five systems for Tesat. In future, a further 50 units per year may follow. “The industrial series production of highly complex systems requires new ways of thinking. This is precisely where our strength lies: setting new standards and opening up new markets in the New Space,” says Dr. Frank Burmeister, former Fraunhofer researcher and now Head of Research and Development at Spaceoptix.
Source: www.iof.fraunhofer.de
Image: Tesat