Briz-M 11D458 vernier engine propellent query-does it pull from the core tank?

[novemberbravo]

I've been trying to find info re how the Briz-M verniers work.

I see they provide ullage for the main engine - but
* how do they get their propellent ullage-less?
* do they have separate tanks?
* or their fuel feed line geometry ensures (capillary action?) that they don't need ullage?
* something else?
* the engines are rated for 1000 second burns and 10,000 cycles - could one burn down 'all' the core tanks using the verniers?

thanks in advance if you have some info ...

[eeergo]

No, the 11D458M vernier/settling thrusters use, like the attitude control 17D58E thrusters, a separate high-pressure propellant system.


The smaller dimensions and the high-pressure make it possible for the system to be restartable without ullage, but I do not know if it includes aids such as membrane tanks or it's enough with capillarity.

[novemberbravo]

thanks !

I don't suppose anyone knows the propellent load for the separate high pressure system?