UPPER-STAGE ROCKET Russian patent published in 2008 - IPC B64G1/40 

FIELD: transport.

SUBSTANCE: upper-stage rocket contains sustainer rocket engine, inter-tank girder, girder-link with carrier vehicle, and fuel tanks one of which has toroidal form and is inclined to longitudinal axis of upper-stage rocket. Toroidal form fuel tank has toroidal bottom gradually adjoint by outer spherical insert levelling it with external frame. Outer frame surface is perpendicular to longitudinal axis of upper-stage rocket and centre of outer spherical insert is located along longitudinal axis of upper-stage rocket.

EFFECT: increase of payload weight at expense of decrease of residual fuel in fuel tank, improvement of manufacturability and assembly of power modules.

1 dwg