3 ms·
The Briz upper stage is an existing design, it wasn't purpose built for Angara, it's been flying with various other rockets. Storable propellants are good for
by Gravityloss 12y ago
The Briz upper stage is an existing design, it wasn't purpose built for Angara, it's been flying with various other rockets.
Storable propellants are good for upper stages that need to do long coast periods and many stops and starts. Apollo used them.
But there are multi-restart versions of lox-hydrogen stages. The RL-10 engine in Delta and Atlas can do it.