In summer 1977, ESA placed the first technological study contract in the domain of intersatellite optical links. Now, twenty years later, a major milestone has been reached with the SILEX laser terminals having been flight tested for integration with their host spacecraft. At the same time, ESA is preparing itself for a new challenge: the potential massive use of optical cross links in satellite constellations for mobile communications and global multimedia services. This is an opportune moment to look back at the past twenty years of ESA effor ....etc

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SILEX

SILEX is a free-space optical communication system which consists of two optical communication payloads to be embarked on the ESA Artemis (Advanced Relay and TEchnology MIssion Satellite) spacecraft and on the French Earth-observation spacecraft SPOT-4. It will allow data transmission at 50Mbps from low Earth orbit (LEO) to geostationary orbit (GEO) using GaAlAs laser-diodes and direct detection.

The SILEX Phase A and B studies were conducted around 1985, followed by technology breadboarding and predevelopment of the main critical ....etc

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In summer 1977, ESA placed the first technological study contract in the domain of intersatellite optical links. Now, twenty years later, a major milestone has been reached with the SILEX laser terminals having been flight tested for integration with their host spacecraft. At the same time, ESA is preparing itself for a new challenge: the potential massive use of optical cross links in satellite constellations for mobile communications and global multimedia services. This is an opportune moment to look back at the past twenty years of ESA effor ....etc

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Definition

The European Space Agency (ESA) has programmes underway to place Satellites carrying optical terminals in GEO orbit within the next decade. The first is the ARTEMIS technology demonstration satellite which carries both microwave and SILEX (Semiconductor Laser Intro satellite Link Experiment) optical interorbit communications terminal. SILEX employs direct detection and GaAIAs diode laser technology; the optical antenna is a 25cm diameter reflecting telescope.

The SILEX GEO terminal is capable of receiving data modulated on to ....etc

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hi i would like to get details about laser satellite communication ....etc

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ABSTRACT
Satellite crosslinks generally require narrower bandwidths for increased power concentration. We can increase the power concentration by increasing the cross page link frequency with the same size antenna. But the source technology and the modulation hardware required at these higher frequency bands are still in the development stage. Use of optical frequencies will help to overcome this problem with the availability of feasible light sources and the existence of eff ....etc

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Optical Communications in Space

In summer 1977, ESA placed the first technological study contract in the domain of intersatellite optical links. Now, twenty years later, a major milestone has been reached with the SILEX laser terminals having been flight tested for integration with their host spacecraft. At the same time, ESA is preparing itself for a new challenge: the potential massive use of optical cross links in satellite constellations for mobile communications and global multimedia services. This is an opportune moment to look back at ....etc

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CHAPTER 1
INTRODUCTION

Communication links between space crafts is an important element of space infrastructure, particularly where such links allow a major reduction in the number of earth stations needed to service the system. An example of an inter orbit page link for relaying data from LEO space craft to ground is shown in the figure below



Interorbit page link for relating data from LEO spacecraft to ground

Fig. 1
Inter orbit page link for relaying data from LEO space craft to ground.


The above figure represents a ....etc

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ABSTRACT
Satellite crosslinks generally require narrower bandwidths for
increased power concentration. We can increase the power concentration
by increasing the cross page link frequency with the same size antenna. But
the source technology and the modulation hardware required at these
higher frequency bands are still in the development stage. Use of
optical frequencies will help to overcome this problem with the
availability of feasible light sources and the existence of ....etc

[:=Read Full Message Here=:]

SILEX

SILEX is a free-space optical communication system which consists of two optical communication payloads to be embarked on the ESA Artemis (Advanced Relay and TEchnology MIssion Satellite) spacecraft and on the French Earth-observation spacecraft SPOT-4. It will allow data transmission at 50Mbps from low Earth orbit (LEO) to geostationary orbit (GEO) using GaAlAs laser-diodes and direct detection.

The SILEX Phase A and B studies were conducted around 1985, followed by technology breadboarding and predevelopment of the main critical ....etc

[:=Read Full Message Here=:]

Definition

The European Space Agency (ESA) has programmes underway to place Satellites carrying optical terminals in GEO orbit within the next decade. The first is the ARTEMIS technology demonstration satellite which carries both microwave and SILEX (Semiconductor Laser Intro satellite Link Experiment) optical interorbit communications terminal. SILEX employs direct detection and GaAIAs diode laser technology; the optical antenna is a 25cm diameter reflecting telescope.

The SILEX GEO terminal is capable of receiving data modulated on to ....etc

[:=Read Full Message Here=:]