The first of in total six new European weather satellites named MetOp-Second Generation is scheduled for launch mid-August. Beyond Gravity provides to all six satellites its world-leading radio occultation instrument, which provides important data for weather forecasts.
Mid-of August the first of a new generation of polar-orbiting European weather satellites will be launched into space. The MetOp-Second Generation satellite will lift off from Europe’s Spaceport in French Guiana aboard the European launch vehicle Ariane 6. The weather satellite will measure humidity and temperature as well as aerosols. “This new European weather satellite, together with its five counterparts, will significantly enhance weather forecasting accuracy and climate change monitoring. A key element of this mission is our radio occultation instrument. Our so-called radio occultation instrument provides important weather data, for example about humidity and temperature, and underlines our capabilities as an important data provider”, says Oliver Grassmann, Executive Vice President Satellites at Beyond Gravity, a leading supplier to the institutional and commercial space industry. Oliver: “Our products will be an integral part of the mission.” In addition to the company’s instrument for radio occultation, Beyond Gravity provided the satellite’s primary structure, thermal insulation, and multiple products for the Ariane 6 launcher. The prime contractor for the satellite is Airbus Defence and Space in Toulouse.
Radio occultation instrument provides important weather data
Beyond Gravity’s radio occultation instrument flies on all six MetOp-Second Generation weather satellites. Radio occultation in space measures how radio signals from satellites bend as they pass through Earth’s atmosphere, helping understand weather, climate, and atmospheric conditions. “Our market-leading radio occultation sounder instrument will provide atmospheric temperature and humidity measurements that will be highly beneficial to weather predictions and climate monitoring. Our technology will enhance Europe’s weather forecasting capabilities for years to come”, adds Oliver Grassmann. “Our radio occultation instrument, launching on the six MetOp-SG spacecraft, will revolutionize radio occultation data with state-of-the-art performance, an extended number of soundings, and continuous global coverage. The instrument will more than double the number of occultations to 2100 per day per instrument.” Chosen by Europe for radio occultation (RO) sounding our instrument will provide RO data until 2050.
Six-meter-high structure and thermal insulation
The six-meter-high structure of all these satellites was built at Beyond Gravity’s site in Zurich (Switzerland). Made of carbon fiber, aluminum, and titanium for critical connections, the structure weighs around one ton. The weather satellite is wrapped in thermal insulation from Beyond Gravity to protect it from the high temperature fluctuations of plus/minus 200 degrees Celsius in space, keeping the interior of the satellite at a constant room temperature, ensuring the smooth functioning of the instruments on board. The insulation consists of several layers of very thin metal-coated plastic and was produced in Berndorf, Austria.
European MetOp weather satellites
European MetOp weather satellites have been orbiting the Earth from the North Pole to the South Pole since 2006. With this satellite, the first of six weather satellites of the latest generation, MetOp-Second Generation, will be launched into space and will join the existing two MetOp weather satellites of the first generation already in orbit*. The MetOp-Second Generation satellites will ensure the continued global observations from polar orbit. In the coming years the further MetOp-Second Generation satellites will be launched. With climate change driving more frequent and severe extreme weather events, precise and timely weather forecasting has never been more critical.
In total, MetOp-Second Generation (SG) consists of six satellites: three successive pairs made up of an A-type and a B-type satellite, which carry a host of different but complementary instruments. The current first satellite is an A-type (MetOp-SG-A). The A-type satellites also carry the Copernicus Sentinel-5 ultraviolet, visible, near-infrared and shortwave infrared to measure key air pollutants and climate-related gases. The MetOp-SG mission has been developed in a long-standing cooperation between European Space Agency (ESA) and Eumetsat.
Payload fairing to protect the weather satellite
The top of the Ariane 6 rocket, on which MetOp-Second Generation will be launched, consists of the payload fairing from Beyond Gravity made of carbon fiber composite. The fairing has a diameter of 5.4 meters. Produced at the Beyond Gravity site in Emmen, Switzerland, the two halves of the payload fairing protect the satellite from the harsh forces experienced during launch and the early flight stages.
Payload adapter for Ariane 6
Furthermore, Beyond Gravity’s site in Linköping (Sweden) provided the payload adapter system for Europe’s heavy-lift launcher Ariane 6. The payload adapter system connects satellite and launcher during liftoff, then precisely releases the satellite into orbit once the proper altitude is reached.
High-temperature insulation for Ariane 6
In Austria, Beyond Gravity produced the high-temperature insulation for the rocket engines of the launcher’s lower and upper stage as well as the engine gimbal for alignment of the rocket’s upper stage. On the journey from Earth to space, the rocket engine, which is protected by the insulation, has to withstand extreme heat of up to 1,500 degrees Celsius for several minutes. The insulation protects the rocket’s exhaust systems around the rocket engine, which runs on oxygen and hydrogen. Also the high-temperature insulation for the upper stage of the Ariane 6 launcher (near the Vinci restartable engine) was supplied. This insulation consists of glass fabric and polymer films.
Gimbal Mechanism for the upper stage
For Ariane 6, the company is also supplying a gimbal mechanism for the upper stage of the rocket. The mechanism serves as a joint to align the engine for the thrust vector control of the rocket's upper stage. The special mechanism, which weighs just ten kilograms, has to transmit the thrust forces of 15 tons, comparable to the force of a diesel locomotive.
MetOp & Meteosat: Combining polar & geostationary orbits
Europe’s weather-monitoring system is based on a dual-orbit strategy, with one satellite family in polar orbit and another satellite family in geostationary orbit. The complementarity of having satellites in both polar orbits and geostationary is key to accurate weather forecasting.
The MetOp weather satellites orbit Earth from pole to pole and at an altitude of 832 km. They can provide data on global coverage every few days and make detailed observations.
In contrast, other European weather satellites, the Meteosat satellites, hover much higher, at 36 000 km above the equator in geostationary orbit (GEO). From there those satellites can monitor rapidly evolving events (e.g. hurricanes) for now-casting and short-term weather prediction. However, being fixed above the equator means that some parts of Earth are never viewed.
*The first generation polar-orbiting weather satellites MetOp-B (launched September 2012) and MetOp-C (launched November 2018) operate at an altitude of 817km. MetOp-A, the first satellite in this series, was deorbited at the end of 2021.
More about the radio occultation instrument from Beyond Gravity:
https://www.beyondgravity.com/en/satellites/electronic-solutions/radio-occultation
https://www.eumetsat.int/metop-sg-instruments
Beyond Gravity’s next generation radio occultation instrument for MetOp-Second Generation offers a number of improvements over the first generation MetOp radio occultation instruments, including:
- More occultations: Up to 2100 per day, more than double the current number.
- Continuous open loop tracking: Measures GNSS signals in all weather conditions.
- More accurate measurements of the troposphere.
- New data on the ionosphere for space weather forecasting.
- More accurate measurements of atmospheric temperature and pressure.
- Accurate measurements even in the presence of strong interference.
Further Information
https://www.esa.int/Applications/Observing_the_Earth/Meteorological_missions/MetOp_Second_Generation
https://www.esa.int/Applications/Observing_the_Earth/Copernicus/Sentinel-5
Images
Image 1: The weather satellite uses a radio occultation instrument from Beyond Gravity. Copyright: ESA. Download: https://www.esa.int/ESA_Multimedia/Images/2017/11/MetOp_Second_Generation
Image 2: Radio occultation instrument from Beyond Gravity. Copyright: ESA. Download: https://www.esa.int/ESA_Multimedia/Images/2006/02/GRAS_uses_radio_occultation_to_measure_vertical_profiles_of_atmospheric_temperature_and_humidity
Videos
Animation of the weather satellite © Eumetsat
Video: Learn how Beyond Gravity is pushing boundaries of what is technically feasible for the benefit of humankind.
