Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Satellite communications by laser

14.05.2008
Satellites currently use radio waves to exchange data. Now the data rate has been increased a hundredfold by using lasers instead of radio signals. Two test satellites each carried a diode laser pump module developed with the help of Fraunhofer researchers.

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
Further information:
http://www.fraunhofer.de/EN

More articles from Information Technology:

nachricht Cloud technology: Dynamic certificates make cloud service providers more secure
15.01.2018 | Technische Universität München

nachricht New discovery could improve brain-like memory and computing
10.01.2018 | University of Minnesota

All articles from Information Technology >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Artificial agent designs quantum experiments

On the way to an intelligent laboratory, physicists from Innsbruck and Vienna present an artificial agent that autonomously designs quantum experiments. In initial experiments, the system has independently (re)discovered experimental techniques that are nowadays standard in modern quantum optical laboratories. This shows how machines could play a more creative role in research in the future.

We carry smartphones in our pockets, the streets are dotted with semi-autonomous cars, but in the research laboratory experiments are still being designed by...

Im Focus: Scientists decipher key principle behind reaction of metalloenzymes

So-called pre-distorted states accelerate photochemical reactions too

What enables electrons to be transferred swiftly, for example during photosynthesis? An interdisciplinary team of researchers has worked out the details of how...

Im Focus: The first precise measurement of a single molecule's effective charge

For the first time, scientists have precisely measured the effective electrical charge of a single molecule in solution. This fundamental insight of an SNSF Professor could also pave the way for future medical diagnostics.

Electrical charge is one of the key properties that allows molecules to interact. Life itself depends on this phenomenon: many biological processes involve...

Im Focus: Paradigm shift in Paris: Encouraging an holistic view of laser machining

At the JEC World Composite Show in Paris in March 2018, the Fraunhofer Institute for Laser Technology ILT will be focusing on the latest trends and innovations in laser machining of composites. Among other things, researchers at the booth shared with the Aachen Center for Integrative Lightweight Production (AZL) will demonstrate how lasers can be used for joining, structuring, cutting and drilling composite materials.

No other industry has attracted as much public attention to composite materials as the automotive industry, which along with the aerospace industry is a driver...

Im Focus: Room-temperature multiferroic thin films and their properties

Scientists at Tokyo Institute of Technology (Tokyo Tech) and Tohoku University have developed high-quality GFO epitaxial films and systematically investigated their ferroelectric and ferromagnetic properties. They also demonstrated the room-temperature magnetocapacitance effects of these GFO thin films.

Multiferroic materials show magnetically driven ferroelectricity. They are attracting increasing attention because of their fascinating properties such as...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

10th International Symposium: “Advanced Battery Power – Kraftwerk Batterie” Münster, 10-11 April 2018

08.01.2018 | Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

 
Latest News

Thanks for the memory: NIST takes a deep look at memristors

22.01.2018 | Materials Sciences

Radioactivity from oil and gas wastewater persists in Pennsylvania stream sediments

22.01.2018 | Earth Sciences

Saarland University bioinformaticians compute gene sequences inherited from each parent

22.01.2018 | Life Sciences

VideoLinks Wissenschaft & Forschung
Overview of more VideoLinks >>>