
The CSO-3 military observation satellite has been successfully launched by Arianespace atop an Ariane 6 from Europe’s spaceport in French Guiana. Carrying a very-high-resolution optical instrument built by Thales Alenia Space, the joint venture between Thales (67%) and Leonardo (33%), the satellite was developed by prime contractor Airbus Defence & Space for the French defense procurement agency DGA on behalf of the French Air and Space Force’s Space Command, with delegated oversight from the French space agency CNES. (Photo by Satnews.)
The third and last component in the CSO system for France’s MUSIS* military program, CSO-3 will provide increased coverage and revisit capabilities to enable more effective conduct of military operations and faster crisis response.
Designed to the most stringent intelligence and defense requirements, CSO-3 is equipped with a cutting-edge instrument developed by Thales Alenia Space. This instrument is the core of the mission, affording exceptional resolution and detail of Earth’s surface. Its unrivaled performance enables it to acquire imagery at extremely high resolution, even in low-light conditions and at night thanks to its infrared capabilities. Its advanced technologies include latest-generation optical systems and ultra-sensitive sensors.

Like for the previous Helios 1, Helios 2 and Pleiades satellites, Thales Alenia Space designed strategic equipment for the CSO system, including the solar arrays, very-high-throughput image telemetry systems, and encryption/decryption modules to ensure data security and confidentiality. The company also supplied the system’s telemetry, tracking and control transponders.

“The launch of CSO-3 is a major milestone for French sovereignty in space, both in terms of launch capabilities and satellite technology,” said Hervé Derrey, Thales Alenia Space CEO. “With the completion of this system, France is leading the way in optical space reconnaissance. The CSO system’s exceptional performance is based in particular on the optical instrument built by the teams at Thales Alenia Space and our industry partners. These unique skills in Europe are strategically important and demonstrate our ability to meet the new challenges facing French and European sovereignty.”
*Multinational Space-based Imaging System for Surveillance, Reconnaissance, and Observation
About Thales Alenia Space
Drawing on over 40 years of experience and a unique combination of skills, expertise and cultures, Thales Alenia Space delivers innovative solutions for telecommunications, navigation, Earth observation, environmental management, exploration, science and orbital infrastructures. Governments and private industry alike count on Thales Alenia Space to design and build satellite-based systems that provide anytime, anywhere connections and positioning, monitor our planet, enhance management of its resources and explore our Solar System and beyond. Thales Alenia Space sees space as a new horizon, helping to build a better, more sustainable life on Earth. A joint venture between Thales (67%) and Leonardo (33%), Thales Alenia Space also teams up with Telespazio to form the parent companies’ Space Alliance, which offers a complete range of services. Thales Alenia Space posted consolidated revenues of approximately €2.2 billion in 2023 and has around 8,600 employees in 8 countries, with 16 sites in Europe.
Arianespace schedules Thursday as new launch for Ariane 6 Flight VA263 with the CSO-3 satellite

Arianespace announced that the CSO-3 satellite launch by Arianespace for France’s DGA and CNES on behalf of the French Air and Space Force’s Space Command is scheduled for March 6, 2025.
The forecast calls for a temperature of 80°F, moderate rain, 100% cloud cover, a wind speed of 8mph and 1.21in of rain.
CSO-3 is the third satellite in the DGA-led MUSIS program (Multinational Space-based Imaging System), a constellation of three satellites dedicated to Earth observation for defense and security purposes.
CSO-1 and CSO-2 were both successfully launched by Arianespace, respectively in 2018 and 2020
Arianespace announces change of schedule for launch of Ariane 6 Flight VA263 with the CSO-3 satellite

Arianespace released a statement regarding the upcoming launch of the Ariane 6 and its passenger, the CSO-3 satellite
Due to further operations needed on a ground means interfacing with the launcher, the VA263 launch is postponed. The new launch date will be announced following the completion of these operations. Ariane 6 and its passenger, the CSO-3 satellite, are in stable and safe conditions.
Earlier in the year David Cavaillolès, CEO of Arianespace, said: “I am very pleased to announce the date of Ariane flight as I take up office. This marks the start of the Ariane 6 operating phase, and it’s an honor to open this new era for Arianespace. With this launch in support of French defense and the capability requirements of several partner nations, Arianespace will guarantee independent access to space for France and Europe, for the benefit of all our fellow citizens.”
Arianespace ‘postpones’ Ariane 6 launch of French CSO-3 with operations underway


Due to further operations needed on a ground means, the launch initially planned on February 26 from Kourou, French Guiana, is postponed.
The new launch date will be announced following the completion of these operations.
Ariane 6 and its passenger, the CSO-3 satellite, are in stable and safe conditions.
CSO-3 is the third satellite in the DGA-led MUSIS program (Multinational Space-based Imaging System), a constellation of three satellites dedicated to Earth observation for defense and security purposes.
CSO-1 and CSO-2 were both successfully launched by Arianespace, respectively in 2018 and 2020.
Arianespace’s Ariane 6 to launch the French Defense Procurement and Technology Agency’s CSO-3 satellite

On February 26, 2025 at 1:24 p.m. local time (4:24 p.m. UTC, 5:24 p.m. CET), Arianespace will launch the CSO-3 satellite with Ariane 6 from Europe’s Spaceport in Kourou, French Guiana. The mission, called VA263, will be the first commercial flight for Ariane 6, the new European heavy-lift launcher. It will place its passenger, the CSO-3 satellite, into Sun-Synchronous Orbit (SSO) at an altitude of around 800 km. Spacecraft separation will occur 1 hour and 6 minutes after lift-off.
David Cavaillolès, CEO of Arianespace, said: “I am very pleased to announce the date of Ariane 6’s first commercial flight as I take up office. This marks the start of the Ariane 6 operating phase, and it’s an honor to open this new era for Arianespace. With this launch in support of French defense and the capability requirements of several partner nations, Arianespace will guarantee independent access to space for France and Europe, for the benefit of all our fellow citizens.”
CSO-3 is the third satellite in the DGA-led MUSIS program (Multinational Space-based Imaging System), a constellation of three satellites dedicated to Earth observation for defense and security purposes.
CSO-1 and CSO-2 were both successfully launched by Arianespace, respectively in 2018 and 2020.
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