The data whizzed back and forth at the speed of light between German satellite TerraSAR-X and US satellite NFIRE, covering more than 5000 kilometers in space without any errors. What was special about this space test recently performed by Tesat-Spacecom was that the data was transmitted by laser.
The bandwidth achieved in the test was a hundred times greater than during conventional communication by radio waves, enabling a data rate equivalent to roughly 400 DVDs per hour. This could make it possible to transmit large data packets between several satellites in the future, for instance to send image data from Earth observation satellites to a ground station.
That has not been possible until now, as the bandwidth of radio waves is not large enough. Another advantage of this new form of communication is that lasers are easier to focus than radio waves, which means that data transmissions can be directed more accurately.
The communication lasers on board the satellite are actuated by pump modules, which were developed to a large extent by researchers at the Fraunhofer Institute for Laser Technology ILT in Aachen on behalf of Tesat GmbH & Co. KG as part of a program financed by the German Aerospace Center (DLR). “The modules have to withstand the vibrations and forces of acceleration on board the satellites during the launch and must then survive the inhospitable conditions in space – such as extreme radiation and strong temperature differences,” says Martin Traub, who led the developments at the ILT.
“We therefore tested the pump modules under extreme conditions in advance, subjecting them to temperatures of -35°C to 60°C, acceleration forces 1300 times as strong as those of the Earth, and gamma rays.” The modules mustn’t be too big or too heavy for use in space: Measuring 5 x 5 x 2 centimeters, they are barely larger than a matchbox, and weigh little more than a bar of chocolate at 130 grams.
“We achieved this minimal weight by selecting the right materials and a sophisticated housing: Any material that wasn’t absolutely essential was milled away,” says Traub. The major challenge is that, despite the reduced weight, the heat generated by the laser’s several-watt output still has to be dissipated.
Martin Traub | Fraunhofer-Gesellschaft
Sensors embedded in sports equipment could provide real-time analytics to your smartphone
16.02.2017 | University of Illinois College of Engineering
Researchers catch extreme waves with higher-resolution modeling
15.02.2017 | DOE/Lawrence Berkeley National Laboratory
In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport
Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...
The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.
The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...
Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...
Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".
Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...
13.02.2017 | Event News
10.02.2017 | Event News
09.02.2017 | Event News
20.02.2017 | Materials Sciences
20.02.2017 | Health and Medicine
20.02.2017 | Health and Medicine