Angara-A5/Persei - Tundra #7? - Plesetsk - NET 2025 (TBD UTC)

[Nicolas PILLET]

On Proton, some Briz-M missions lasted as long as 14 hours, IIRC. That is technically VERY challenging for thermal control, telemetry, and many other things. For example, a standard Ariane 5 missions lasts about 32 minutes. The ESC-A upper stage, and it's ground segment, would be completely unable to accomplish 14-hour missions. Briz-M has a bad reliability history, and it is mainly due to this.

Block D ability to conduct relatively short mission profiles is definitely a great advantage over the Briz, which has been developed at first for a light launcher (Rokot).

[Nicolas PILLET]

So what I understand is that the satellite is not launching on Briz-M mainly due to the ego of Energia boses, they are like "our satellite, so our upper stage only, Khrunichev not getting our spot and our money"

It is not a matter of ego, it is a matter of money. Imagine you launch your satellite on a Falcon 9 but you tell Elon that you want a Boeing upper stage instead of his upper stage. He will answer 'OK, but it will cost you more'.

[AndrewM]

Safe to say this is bumping to 2026 now or has there been any recently announced progress on the investigation into the upper stage issue?