MTG-S1

The Meteosat Third Generation Sounder 1 (MTG-S1) satellite carries the Copernicus Sentinel-4 ultraviolet-visible-near-infrared (UVN) imaging spectrometer as a hosted instrument.

Planet4589 ephemeris reports cataloged MTG-S1 in a 334 x 65,206 km supersynchronous transfer orbit with 21.2 degrees inclination following launch on July 1, 2025.

ESA and EUMETSAT acquisition data recorded acquisition of signal at 23:39 CEST on July 1, 2025 followed by deployment of MTG-S1 solar arrays during LEOP.

MTG-S1 reached a geostationary longitude near 3.5° West and was measured at approximately 35,788 x 35,786 km with 1.00° inclination in mid-July 2025.

Hazardous propellant loading activities for MTG-S1 and the Sentinel-4 instrument began on June 17, 2025 as part of pre-launch processing.

ESA released the first official MTG-S1 Infrared Sounder images showing atmospheric temperature and humidity on December 15, 2025, with the images publicly posted by ESA on January 27, 2026.

MTG-S1 was encapsulated inside the Falcon 9 payload fairing and mated to its flight adaptor during final launch campaign operations in late June 2025.

NOTAM and NGA notices established hazardous operation areas and launch windows for the MTG-S1 Falcon 9 launch with primary launch dates and daily windows from 21:03 UTC to 00:15 UTC on July 1–7, 2025.

On March 10, 2025 a special temporary authority (STA) SES-STA-20240925-02028 was granted for Universal Space Network, Inc. for 180 days beginning March 11, 2025 through September 6, 2025 to operate a fixed earth station in Naalehu, Hawaii to provide LEOP support to MTG-S1 at Earth-to-space center frequency 2075.0979 MHz and space-to-Earth center frequencies 2253.5 MHz, 2243.5 MHz, 2246.5 MHz, and 2258.5 MHz.

Eumetsat switched the MTG-S1 and MTG-I2 launches to Ariane 6 because Ariane 5 will be unavailable after 2022.

MTG-S1 will launch on an Ariane 64, the Ariane 6 configuration equipped with four solid rocket boosters.

MTG-S1, a sounding satellite that previously had a firm Ariane 5 launch contract, is scheduled to launch in 2023 on an Ariane 6 rocket.

EUMETSAT moved the MTG-S1 weather satellite launch from Ariane 6 to SpaceX Falcon 9 to ensure the spacecraft would launch in 2025.

Eumetsat moved the MTG-S1 launch from Ariane 6 to Falcon 9 to ensure the spacecraft would launch in 2025 and agreed to use Ariane 6 for future satellite launches.

A Falcon 9 launched the MTG-S1 weather satellite for Eumetsat from Kennedy Space Center in 2025.

Eumetsat moved its MTG-S1 geostationary weather satellite to a Falcon 9 launch last month after previously planning to fly it on Ariane 6.