The MetOp Second Generation-A1 satellite has reached a significant milestone in its journey to orbit, with fuelling operations now complete at Europe's Spaceport in French Guiana. Engineers successfully loaded 790 kg of hydrazine onto the spacecraft, paving the way for the next phase of pre-launch activities.
This satellite, MetOp-SG-A1, is the first in a series of three A-B satellite pair by Erica Marchand
Paris, France (SPX) Jul 25, 2025
The MetOp Second Generation-A1 satellite has reached a significant milestone in its journey to orbit, with fuelling operations now complete at Europe's Spaceport in French Guiana. Engineers successfully loaded 790 kg of hydrazine onto the spacecraft, paving the way for the next phase of pre-launch activities.
This satellite, MetOp-SG-A1, is the first in a series of three A-B satellite pairs designed to deliver high-resolution, global atmospheric data from polar orbit for the next two decades. The mission, jointly developed by ESA and Eumetsat, promises improved accuracy in weather forecasting and expanded climate monitoring capabilities over its MetOp predecessors.
Each A- and B-type pair carries a suite of ten instruments in total, split between them to provide complementary observations. MetOp-SG-A1 hosts six payloads, including a next-generation infrared sounder, a microwave sounder, a multispectral imaging radiometer, a new multiviewing and multipolarisation imager, a radio occultation instrument, and ESA's advanced Copernicus Sentinel-5 spectrometer.
The Sentinel-5 instrument builds on the earlier Sentinel-5 Precursor satellite and will deliver daily global measurements of key atmospheric pollutants, greenhouse gases, and stratospheric ozone. The spectrometer is designed to operate in synergy with other instruments aboard MetOp-SG-A1, and in tandem with Sentinel-4, which monitors atmospheric composition hourly from geostationary orbit.
"The MetOp-SG-A1 satellite is a big satellite, weighing well over 4000 kg including the fuel," said ESA's MetOp-SG Project Manager, Marc Loiselet. "The task of fuelling is always a hazardous undertaking and one that needs specialists to carry out. We are happy to report that the procedure was executed perfectly and our satellite is now 'fully loaded'."
Following fuelling, the satellite will undergo final systems checks before entering the "combined operations" stage, which includes integration with the Ariane 6 launcher and encapsulation in its payload fairing. Launch is scheduled for August.
"This is also great news of course for the Sentinel-5A instrument, which is one of the Copernicus missions dedicated to atmospheric monitoring," added Didier Martin, ESA's Sentinel-5 Project Manager. "By virtue of MetOp-SG-A1's polar orbit, Sentinel-5 is complementary to the recently launched Sentinel-4."
The MetOp-SG program is part of a long-standing collaboration between ESA and Eumetsat, with ESA managing satellite development and Eumetsat overseeing launch services, operations, and data delivery. The Sentinel-5 mission is coordinated through ESA and the European Commission in partnership with Eumetsat, industry, and the user community.
A pre-launch briefing will be broadcast live on ESA Web TV One at 14:00 CEST on Monday, 28 July.
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