10 Years of Laser Communication from Germany
1983 is a special year for telecommunication via lasers. This year, the foundation stone for the development of a laser terminal in Germany was laid. Since then, much has happened, the world has changed and more and more areas of application have crystallized. In today‘s times, when bandwidths increase day by day, and data sets for all conceivable fields of application are increasing, it is difficult to imagine how impressed people were 30 years ago by even small milestones.
At the end of the 80s, the first telephone modems entered the private households, which at this time represented with the performance of up to 300 bit / sec. the upper end of the food chain. Relatively soon thereafter more powerful variants followed up, until with the ISDN the first great milestone was reached. DSL, Ethernet and Gigabit Ethernet were logical consequences and technical developments of a cable-based data transmission, at which we are currently talking about transmission rates of up to one gigabit per second.
In the area of wireless transmission, radio has been and is still a measure of things that are used by many – also space-oriented topics. The pioneer of data transmission through the air achieves today about 300 Kbit / sec., newer representatives like Bluetooth (25 Mbit / sec.), WiFi (54 Mbit / sec.) or LTE (150 Mbit / sec.) raise the bar considerably higher.
So there is already so much and it becomes more and more. Nevertheless, our pioneers, who started working on the development of telecommunication via laser in 1983, decided to transfer data by an optical signal – after all, this had worked with signal lamps on the high seas for decades.
Ten years ago, in 2007, the first great milestone: The first laser communication terminal (LCT) sees the light of the exosphere. In 2008 the first link between two satellites followed and Tesat-Spacecom is and remains the only company worldwide that enables this technology.
Fast, Reliable and over all Distances
Tesat-Spacecom has been the world leader in the development and manufacturing of laser communication terminals (LCTs) for more than 10 years. The world‘s first inter-satellite links were made possible and realized at the time using this groundbreaking technology. It is therefore only logical that the next milestone in the field of optical broadband communication comes from Backnang, Germany.
This next big milestone is the further development of the LEO135 earth observation pioneer to a SMARTer product – LEO SMART – with the same performance, but lower size, weight, power and cost. In the future the LEO SMART (2) inherits the venerable LEO135. Like its predecessor, it will be able to produce inter-satellite links over a distance of up to 45,000 km at data rates of 1.8 Gbit / sec. The biggest difference are its dimensions and weight, which could be reduced by a factor of three. The compatibility with the geostationary GEO135 (1) backbones, which already have a long heritage in orbit, is also guaranteed. The new LCT with the nickname „The Future User“ is perfectly matched to the low earth orbit (LEO) data relay market, whose prominent representatives are, for example, the Sentinel satellites of the European Copernicus program.
Another new feature in the field of laser communication is the ConLCT (3) , which has been designed specifically to meet the needs and functionalities of LEO satellite constellations. The goal was also to keep mass and dimensions as low as possible at maximum performance. The ConLCT is designed to provide a „grid matrix“ for constellations with four individually adjustable laser communication terminals, which have a range of up to 6,000 km for inter-satellite links – even data rates of up to 5 Gbit / sec. are possible over this distance. „The Specialist“, as the ConLCT is also called, is thus a perfect fit for the constellation market, like the European GPS competitor Galileo.
For the upcoming “Direct-to-Earth” (DTE) market, Tesat-Spacecom has the LEO-DTE (5) , which is even smaller and reduces the size and weight once more by a factor of four. With a weight of less than 5 kg and a size that would easily fit into any glove box, it is capable of establishing a data link at a rate of up to 10 Gbit / sec. over a distance of 1,500 km.
The latest pioneer project is called “CubeL” (4) . With this technology, slowly but surely the maximum lower limit for external factors such as size and weight is reached. The candidate for the CubeSat market weighs just 250 g. Nevertheless, it will be possible to maintain downlink data rates of about 100 Mbit / sec. over a distance of 1,500 km.
Not only in space, but also on ground Tesat-Spacecom has with their Optical Ground Station (6) the technology and expertise of the back-end for all common wavelengths – 1064 nm and 1550 nm – which have been in use for a long time on Tenerife, Spain.
Benefits of Laser Communication in Space
Our pioneers were from early on aware of that the amount of data that will be transmitted over long distances in the future will become even greater. So our fastest horse in the stable is currently able to send 1.8 Gbps over a distance of up to 80,000 km, loss-free and absolutely bugproof and interference-resistant. This becomes relevant in situations where time actually means everything. In the event of natural catastrophes, where rapid humanitarian aid can save lives, in the case of distress at sea in which damaged ships and survivors have to be catered for in the shortest possible time, or in the case of global issues such as climate change and the melting of the polar carcasses, Laser Communication Terminals from Tesat-Spacecom are in use.