MTG-S1 and Sentinel-4 launch to change how we see our atmosphere

Both MTG and Copernicus Sentinel-4 are world-class Earth observation missions developed by the European Space Agency (ESA) with European partners to address scientific and societal challenges.

The MTG-S1 satellite has been designed to generate a completely new type of data product, especially suited to nowcasting rapidly evolving storms, with three-dimensional views of the atmosphere. Its Infrared Sounder will be the first European hyperspectral sounding instrument in geostationary orbit, allowing it to hover over Europe and provide:

• a profile of temperature and moisture at different altitudes over Europe every 30 minutes; and
• data on aerosols, ozone, nitrogen dioxide and sulphur dioxide over Europe and Africa every 60 minutes. 

And Copernicus Sentinel-4, which consists of an instrument mounted on the MTG-S1 satellite, will be the first mission to monitor European air quality from geostationary orbit. Its fixed position over the equator enables it to keep its ultraviolet, visible and near-infrared (UVN) imaging spectrometer focused on Europe and northern Africa. It will measure:

• pollution every 60 minutes with a level of detail and precision that will transform how we predict air quality across Europe.

ESA’s Director of Earth Observation Programmes, Simonetta Cheli, said, “These two groundbreaking missions are set to change the way we forecast both severe weather and the quality of air over Europe. It is thanks to the outstanding work our teams have done with Eumetsat, the European Commission and dozens of European industry partners, that we are able to now look forward to more accurate and timely ways of predicting storm events and air pollution.”

Phil Evans, Director General of Eumetsat, said, “MTG-S1 will provide entirely new types of data products that will support specialists across Eumetsat member states to detect signs of atmospheric instability even before clouds begin to form. Combined with data from the MTG imaging satellites it will, for the first time, offer a space-based view of the full lifecycle of convective storms. This will provide tremendous support to national meteorological services in carrying out their vital work, helping to save lives, reduce disruption, and strengthen resilience.”

“Congratulations to all those involved in the launch of Copernicus Sentinel-4. This new Copernicus mission is expected to improve Europe’s capability to monitor the atmosphere from space. Data from this mission will be invaluable for the Copernicus Atmosphere Monitoring Service (CAMS), which already greatly contributes to public health and environmental monitoring, among others,” said Christoph Kautz, Director for Space Policy, Satellite Navigation and Earth Observation, European Commission (DEFIS).

MTG-S1 and Copernicus Sentinel-4 were launched on Tuesday, 1 July, by SpaceX on a Falcon 9 rocket, from Cape Canaveral in Florida, US. Lift off was at 23:04 CEST (17:04 local time). Acquisition of signal was confirmed at 23:39 CEST, followed by deployment of the satellite’s solar arrays, indicating that the mission now has sufficient power. This is a key point at which the mission teams recognise the success of the launch.

About MTG-S1

The MTG mission already launched one satellite – the MTG-Imager (MTG-I) – so MTG-S will be the second MTG satellite in orbit. Its Infrared Sounder uses interferometric techniques to capture data on temperature, humidity, wind and trace gases that are used to generate three-dimensional maps of the atmosphere, helping to improve the accuracy of weather forecasting.

The Infrared Sounder will be the first hyperspectral sounding instrument placed in geostationary orbit by a European-led mission. It will be positioned about 36 000 km above the equator and will maintain its position relative to Earth, following the same area on the planet’s surface as we rotate. It will provide coverage of Europe and part of northern Africa on a repeat cycle, providing meteorologists with a complete weather picture of the region, complementing data on cloud formation and lightning from MTG-I.

“This mission – and of course everyone involved in the project – have been on an incredible journey,” said James Champion, ESA’s MTG Project Manager.

“We now have very high expectations that the Infrared Sounder will indeed be a gamechanger for making more accurate and timely predictions of extreme weather, making a real difference to people’s lives and livelihoods across Europe and northern Africa.”

Thales Alenia Space was the prime contractor for the overall MTG mission, with OHB Systems responsible for the MTG-Sounder. Mission control and data distribution will be managed by Eumetsat.

About Copernicus Sentinel-4

The MTG-S satellite hosts the UVN spectrometer for the Copernicus Sentinel-4 mission. Copernicus is the Earth observation component of the European Union’s Space Programme. The spectrometer delivers high-resolution data on gases that affect the quality of the air we breathe, including a wide range of atmospheric trace gases and pollutants such as nitrogen dioxide, ozone, sulphur dioxide and formaldehyde.

The mission will complement the Sentinel-5 and Sentinel-5P missions, which provide daily observations of Earth from polar orbits.

Sentinel-4 is the European Union contribution to the global constellation of geostationary air quality sensors. It will work alongside the Korean sensor Gems, observing air pollution over Asia, and NASA sensor Tempo, measuring air pollution over North America.

“Sentinel-4 brings something truly new to the Copernicus family of Sentinel Earth observation satellites, and we at ESA are incredibly proud to have contributed to bringing the mission through development to launch,” said Giorgio Bagnasco, ESA’s Sentinel-4 Project Manager. “This mission has an incredibly sensitive and precise instrument, which will transform how we predict atmospheric pollution and understand air quality trends.”

The prime contractor for Sentinel-4 is Airbus Defence and Space. As with the MTG-S1 satellite, mission control and data distribution for Sentinel-4 will be managed by Eumetsat.