Unique configuration with oxidizer in core and fuel in two tanks strapped on in parallel - all of rail-transportable 3.9 m diameter. Buildt by NPO Energia to Khrunichev design (their own design for Angara and Energia-M were rejected in favor of Khrunichev version). Masses estimated based on engine selected and vehicle performance. Assumed that engine is throttled back to maintain constant 3-G acceleration.