First MetOp Second Generation-B satellite spreads its wing

The MetOp Second Generation (MetOp-SG) mission relies on a pair of complementary satellites to strengthen Europe’s weather forecasting capabilities from polar orbit.

The first, MetOp-SG-A1, was launched in August 2025, and engineers are now preparing its companion, MetOp-SG-B1, to enter orbit this autumn.

Working together, both satellites carry complementary suites of instruments – 11 between them – to provide high-resolution measurements of temperatures, precipitation, clouds, winds and other key atmospheric and environmental variables.

As one of the most advanced atmospheric monitoring systems ever deployed, the MetOp-SG mission consists of three sequential pairs of satellites that provide essential global data to help meteorologists predict storms, track climate trends, and improve the accuracy of everyday weather forecasts for more than two decades.

The MetOp-SG B-type satellites carry five instruments: a scatterometer to provide sea-surface wind vectors and land-surface soil moisture, a radio occultation sounder (which is also on A-type satellites) to provide atmospheric temperature and humidity profiles, as well as information about the ionosphere, a microwave imager to monitor precipitation and assess sea-ice extent, and a microwave imager to measure cloud-ice water. an ice cloud imager for, and an Argos-4 advanced data collection system that collects and transmits data from surface, buoys, ships, balloons, and airborne platforms.

Over the past year, the MetOp-SG-B1 has been undergoing rigorous environmental and functional testing at Airbus facilities in Toulouse, France. Among the most notable recent milestones has been the deployment of its large solar wing.

Spanning 11 meters when fully extended, and with a total surface of approximately 24 square metres, the four-panel solar wing is the satellite’s primary source of electrical power. It converts sunlight into electricity needed to operate the satellite’s subsystems, communications links and scientific instruments throughout its mission in polar orbit.

Before launch, engineers must confirm that the solar wing’s hinges, hold-down and release mechanisms, and deployment systems function flawlessly.

Once in orbit, the solar wings will automatically open immediately after separation from the satellite’s Ariane 6 rocket, a critical step before starting its mission in orbit.

Now that these tests are complete, the next step is to weigh the satellite, followed by placement on a dedicated rig to measure its center of gravity and moments of inertia. These are important parameters for the rocket to optimize the satellite’s ascent into orbit – just as an aircraft crew confirms passenger load and fuel before takeoff.

After this, the satellite will be ready for flight. After a rehearsal of the procedures to be carried out at the launch site, it will be stored in an Airbus cleanroom for approximately four months before shipment to Kourou for launch, which is currently scheduled for October 2026.