Estrack tracking stations
The ESA tracking station network – Estrack – is a worldwide system of ground stations providing links between satellites in orbit and our operations centre ESOC. The core Estrack network comprises 10 stations in seven countries.
The essential task of all ESA tracking stations is to communicate with our missions, up-linking commands and down-linking scientific data and spacecraft status information. Estrack stations also gather radiometric data to help mission controllers know the location, trajectory and velocity of their spacecraft.
Estrack stations provide additional services, including searching for and acquiring newly launched spacecraft, auto-tracking, frequency and timing control using atomic clocks and gathering atmospheric and weather data. Some stations are also equipped with GPS receivers connected to our GPS Tracking and Data Analysis Facility at ESOC, enabling highly precise orbit and geophysical calculations.
Each ESTRACK station hosts one or more terminals, each of which comprises an antenna and its associated signal processing equipment. Stations can support multiple missions and Estrack also shares resources with other agencies and satellite operators.
Estrack Core Network
The Core Network comprises 10 stations: Kourou (French Guiana), Maspalomas, Villafranca and Cebreros (Spain), Redu (Belgium), Santa Maria (Portugal), Kiruna (Sweden), Perth and New Norcia (Australia) and Malargüe (Argentina).
During routine operations, stations are remotely operated from the Estrack Control Centre (ECC) at ESOC.
All stations host 13-, 13.5- or 15-metre antennas, except New Norcia, Cebreros and Malargüe, which are or will be equipped with 35-metre deep-space antennas, and Santa Maria, with a 5.5m antenna. Older stations communicate using a mix of S-, Ka- and X-Bands (2025-2300 MHz, 18.1-32.3 GHz, 7145-8500 MHz, respectively), while the two new 35m DSA stations primarily use the newer X-band.
Data rates vary greatly depending on the mission, direction (up-link or downlink) and other factors, but typically range from 256 Kbit/s (kilobits per second) to 8 Mbit/s (megabits per second).
Six Estrack stations are equipped with GPS (global positioning satellite) receivers and are connected to ESA's sophisticated GPS-based Tracking & Data Analysis Facility, while the two deep-space stations are equipped with extremely accurate delta-DOR (delta-Differential One-way Range) spacecraft tracking technology.
Santa Maria joined Estrack in January 2008 to track launches from ESA's Spaceport in Kourou, initially supporting the ATV launch on Ariane 5.
The Estrack Core Network typically provides over 45 000 hours of tracking support each year, and enjoys an enviable 99-percent availability rate.
ESA Deep Space Antennas
Estrack's 35m stations at New Norcia (Deep Space Antenna – DSA 1) Cebreros (DSA 2) and Malargüe (DSA 3) form the European Deep Space Network.
The 35m stations provide the improved range, radio technology and data rates required by current and next-generation exploratory missions such as Mars Express, Venus Express, Rosetta and BepiColombo.
Deep-space missions are typically more than 2 million kilometres away from the Earth, and communicating at such distances requires highly accurate mechanical pointing and calibration systems.
DSA 1, 2 and 3 also have facilities for radio science experiments, allowing scientists to study the characteristics of matter through which the spacecraft-ground communication signals travel.
New Norcia and Cebreros were completed in November 2002 and September 2005, respectively, while Malargüe entered routine service in January 2013.
ESTRACK Augmented Network
The Estrack system is complemented by commercially operated stations provided thru service contracts with organisations such as the Swedish Space Corporation (SSC) and Kongsberg Satellite Services AS (KSAT, Norway).
- SPH-1/2 at South Point, Hawaii (USA)
- AGO-1 in Santiago (Chile)
- TR-1 at TrollSat, Antarctica (Norway)
- SG-3 at Svalbard (Norway)
- DON-1/2 at Dongara (Australia)
Estrack Cooperative Network
Additional Estrack Cooperative Network stations are provided on a resource-sharing basis by other organisations, including ASI (Italy), CNES (France), DLR (Germany), NASA's Deep Space Network and Goddard Space Flight Centre and JAXA (Japan).
These stations have supported Mars Express, Integral, Venus Express and Rosetta, among many others.
This global network allows ESA missions to make use of a wide number of ground terminals in geographically advantageous locations, mainly during LEOP or other critical mission phases.
Conversely, Estrack resources are also shared with other agencies to maximise efficiency and enhance scientific returns.
For example, ESA presently has specific Memorandum of Understanding (MOU) agreements in place for NASA Deep Space Network (DSN) support to Mars Express, Venus Express and Rosetta, while the ATV vessels use NASA's Tracking and Data Relay Satellite System (TDRSS) network while flying to the ISS.
EU, International regulations and standards
Estrack terminals operate in the ITU (International Telecommunications Union) frequency bands allocated to the "space science services" and to the "fixed-satellite service" in the case of Artemis – ESA's telecommunications satellite – supported from Redu.
In accordance with ITU radio regulations and agreements between ESA and the station host countries, ESTRACK terminals respect the requirements on minimum elevation angle and maximum power radiated toward the Earth surface, as well as any site-specific constraints included in these agreements.
Individual frequency licenses are obtained for any missions to be supported by ESTRACK. ESTRACK stations are designed in accordance with the European Cooperation for Space Standardisation (ECSS) standards.
Typical Estrack station technical profileThe table below provides the technical profile of a typical ESA S- or X-band ground station. Note for comparison that a typical 'high-speed' home DSL Internet connection in Western Europe provides a download data rate of 1.5-5 mbps.
|Antenna dish diameter||15m, 35m|
|Normal data rate||up to 1 Mbps|
|Maximum data rate||up to 105 Mbps|
|Normal data rate||2 Kbps|
|Range accuracy||1 m|
|Range rate accuracy||0.1 mm/s|
Last update: 22 January 2013