European Data Relay Satellite
The European Data Relay Satellite System (" European Data Relay Satellite System ", EDRS for short) is a system of geostationary communication satellites that are intended to enable continuous data transmission between satellites and UAVs and ground stations.
The system also enables full-time communication with satellites in near-earth orbit, which often have very little visibility from ground stations. It will make data available in the right place and at the right time and thus, for example, provide rescue workers with near-real-time satellite data and information on the crisis region in which they are active. A satellite in near-earth orbit has an orbit time of approx. 100 minutes, of which it is a maximum of 10 minutes, i.e. 10% of the orbit time in the field of vision of the ground station. On the other hand, a relay satellite in geostationary orbit is visible from this satellite for 25% of the orbit time. EDRS makes use of this principle. The satellite in LEO can use a laser to send its data broadband to the satellite in GEO and this sends the data to the ground station via the Ka-band. This connection is permanent, so that a significantly larger amount of data can be transported in this way. The satellites in GEO can exchange data with each other using lasers. With several satellites you can further improve coverage.
The system was developed as part of the ARTES-7 program and is intended to replace the Artemis satellite . It is to be developed in order to reduce time delays in the transmission of large amounts of data. The program is similar to the American tracking and data relay satellite system that was used to communicate with the space shuttles . EDRS will use a new generation of LCT technology from Tesat-Spacecom . The LCT is designed in such a way that 1.8 Gbit / s can be transmitted over distances of 45,000 km - which corresponds to the distance of a LEO-GEO connection. Such a terminal has already been successfully tested during the in-orbit verification between the German radar satellite TerraSAR-X and the American satellite NFIRE . An LCT is on board the commercial telecommunications satellite Alphasat for further system and operational demonstrations.
The system
The EDRS infrastructure will consist of two geostationary payloads (two additional payloads are already in the planning stage), a ground segment consisting of a satellite control center, a mission & operations center, a feeder link ground station (FLGS) and ground stations for receiving data.
Space segment
The first EDRS payload (EDRS-A), a laser communication terminal and a Ka-band satellite link, was launched on January 27, 2016 on board the telecommunications satellite Eutelsat 9B with a Proton M and positioned at 9 ° East. An EDRS-B satellite was originally planned, but has not yet been implemented.
In contrast to EDRS-A, EDRS-C is an independent satellite. It was launched with an Ariane 5 on August 6, 2019 at 9:30 p.m. ( CEST ).
These two components of the space segment form the basic infrastructure in space and enable direct coverage for LEO satellites over Europe, the Middle East, Africa, America, Asia and Poland.
A third satellite, EDRS-D, is scheduled to be deployed over Asia or the Pacific in 2020 or 2021. With the exception of a few gaps over North America and the North Pacific, the entire earth is covered.
Ground segment
EDRS's ground segment consists of three ground stations in Weilheim (Germany), Redu (Belgium) and Harwell (Great Britain). The central Mission Operations Center will be in Ottobrunn , while a backup will be installed in Redu.
Both the EDRS-A payload and the EDRS-C satellite are operated by the German Space Control Center (GSOC) of DLR in Oberpfaffenhofen near Munich.
business
The first EDRS users will be the Sentinel 1 and 2 satellites of the GMES program. The Sentinel satellites provide data for the operational delivery of geospatial products and services across Europe and worldwide. The EDRS data transmission services for the Sentinel satellites enable a fast downlink of large amounts of data. Extensive additional capacities on the system will be available for additional users.
A number of important applications will benefit from EDRS:
- Earth observation services to support time-critical and / or data-intensive applications, such as B. Change monitoring, environmental monitoring.
- Government and security services that need data from major European satellite systems such as: B. Global Monitoring for Environment and Security.
- Crisis intervention teams and rescue workers who need timely information and data from crisis areas.
- Security guards who need to transmit data to Earth observation satellites, airplanes and unmanned aerial vehicles to reprogram the systems in real time.
- Weather satellite services that need fast delivery of large amounts of data around the world.
In early June 2017, the system transmitted a high-resolution image from Sentinel-2B to Earth for the first time.
implementation
EDRS is operated as a public-private partnership (PPP) between the European Space Agency (ESA) and Airbus Defense and Space . ESA is funding the infrastructure development and is the main customer through the Sentinel satellite missions. Airbus Defense and Space has overall responsibility for the implementation of the space segment including the satellite launches and the implementation of the ground segment. Airbus Defense and Space will then own the EDRS system and provide the data transfer services for ESA and customers worldwide.
Web links
Individual evidence
- ↑ ESA: ARTES 7 EDRS Overview ( Memento from May 25, 2011 in the Internet Archive )
- ↑ TerraSAR-X NFIRE test
- ↑ ESA: Alphasat: Transferring data with laser light
- ↑ EDRS European Data Relay Satellite System - Project Implementation Plan. (PDF; 0.1 MB) European Space Research and Technology Center , June 27, 2008, accessed on August 2, 2019 .
- ^ European Data Relay Satellite. European Space Agency, September 30, 2016, accessed May 29, 2017 .
- ↑ Tereza Pultarova: Space Data Highway to add third node for global coverage. Space News, March 15, 2017, accessed June 1, 2017 .
- ↑ ESA: Redu to house operations center for EDRS satellite relay. March 7, 2012, accessed June 1, 2017 .
- ↑ DLR - Space Operations and Astronaut Training - EDRS ( Memento from March 4, 2016 in the Internet Archive )
- ↑ ESA: First Sentinel-2B images delivered by laser