On July 25, 2025, the Vostochny Cosmodrome is set to launch the Ionosfera-M satellites #3 and #4. This information was announced by Roscosmos` press service.
The launch of the Soyuz-2.1b rocket, equipped with a Fregat upper stage and the two main satellites, along with 18 small spacecraft as secondary payloads, is scheduled for 8:54 AM Moscow time.
After liftoff, the Fregat upper stage carrying the satellites will separate from the rocket`s third stage 9 minutes and 24 seconds into the flight. The Fregat will then activate its main engine twice to propel the spacecraft into their designated orbits. The separation of the Ionosfera-M satellites is expected to occur 1 hour, 2 minutes, and 35 seconds after launch.
Half of the eighteen small satellites were developed by Geoscan. These are designed for Earth imaging, tracking air and sea vessels, and studying space phenomena. Additionally, several educational satellites will be used for researching space-to-Earth radio links and conducting experiments on controlling small spacecraft in low Earth orbit.
Roscosmos specified that the Russian satellites will be launched inside containers provided by Aerospace Capital. These containers will remain closed during launch but will open after reaching orbit, allowing the CubeSats to deploy into their respective orbits.
Among the small satellites will also be NAHID-2, an Iranian telecommunications satellite manufactured by the Iranian Space Research Center (ISRC) and launched under a commercial contract for the Iranian Space Agency (ISA).
The first two Ionosfera-M spacecraft were successfully launched from Vostochny on November 5, 2024, using the same type of rocket. Roscosmos reported the completion of their state tests on May 13, 2025. Each of these satellites weighs over 400 kilograms and operates at an orbital altitude of 820 kilometers. The second pair will be placed into the same orbit.
All four satellites will form the Ionozond system, which is designed to monitor changes and phenomena within the ionosphere and to provide timely information about the heliogeophysical environment, commonly referred to as “space weather.”
Ionosfera-M #3 and #4 are notable as the first spacecraft to be transported by plane to the Vostochny Cosmodrome, following the recent commissioning of its airport complex.
This upcoming launch marks the first from Vostochny this year, the 19th Soyuz rocket flight from this site, and the 20th launch in the cosmodrome`s history. Overall, it will be the ninth launch in Russia`s 2025 space program.
Rupert Blackwood 
Clement Ashworth