Leading companies worldwide continuously explore opportunities to increase the effi ciency of launching payloads into near-Earth
space. One of the main directions in improving launch vehicles is reducing their structural mass. Th is work addresses the practical
problem of designing a propellant pipeline for a cryogenic propellant used in a launch vehicle. Th e propellant pipeline delivers liquid
oxygen from the tank to the propulsion system in the fi rst stage and passes through the tunnel duct of the fuel tank. Replacing
traditional aluminum alloys with composite materials enables reducing the mass of the launch vehicle’s structure. Carbon fi berreinforced
plastic (CFRP) is the most appropriate composite material due to its superior specifi c strength. Th is article presents the
necessary input data and a design methodology that includes the calculations of the linerless composite propellant pipeline volume,
geometry, and mass. Th e determination of key parameters includes calculating the pipeline diameter based on the propellant fl ow
rate, the pipeline wall thickness based on strength requirements, and insulation thickness based on heat-transfer characteristics.
Th e resulting mass of the propellant pipeline is determined, and its design development begins. Design development includes
creating drawings of the propellant pipeline structure based on the available initial data and the determined geometric parameters.
Th e proposed methodology allows designers to estimate key parameters of a launch vehicle’s propellant pipeline during early phases
of development. Th e article also provides a geometric implementation of the pipeline and describes the specifi city of integrating it
into the structure of a launch vehicle stage. Ensuring the leak tightness of the propellant pipeline under mechanical and thermal
loads is critical during integration.