A cryogenic and superconducting powertrain comprising: - at least a superconducting e-motor, including a motor shaft, - at least a motor control unit configured to control the functioning aspects of the superconducting e-motor, - a propeller lead by the superconducting e-motor, - a gearbox, arranged between the superconducting e-motor and the propeller, and configured to control a rotating speed of the motor shaft, - at least a fuel cell, which comprises a DC power supply, - main current leads to the fuel cell, - at least a DC line, and - at least a DC/DC converter to adapt voltage levels between the DC line and the main current leads, wherein the main current leads and the DC line have different working voltage levels, a Thermal Management System for managing the temperature of the fuel cell, and, - a cooling architecture comprising: - a liquid hydrogen (LH 2) tank for LH 2 storage at cryogenic temperature, - LH 2 circulation pipes starting and ending at the LH 2 tank, - a first heat exchanger (36, 36a, 36b) configured to exchange heat between a first fluid and a second fluid, - a first cryostat of second fluid for cooling the motor control unit and the superconducting e-motor, - a second cryostat (50a, 50b) of second fluid for cooling the DC/DC converter, and - second fluid circulation pipes (42, 54a-k), starting and ending at each cryostat (38, 50a, 50b). - at least a superconducting e-motor, including a motor shaft, - at least a motor control unit configured to control the functioning aspects of the superconducting e-motor, - a propeller lead by the superconducting e-motor, - a gearbox, arranged between the superconducting e-motor and the propeller, and configured to control a rotating speed of the motor shaft, - at least a fuel cell, which comprises a DC power supply, - main current leads to the fuel cell, - at least a DC line, and - at least a DC/DC converter to adapt voltage levels between the DC line and the main current leads, wherein the main current leads and the DC line have different working voltage levels, a Thermal Management System for managing the temperature of the fuel cell, and, - a cooling architecture comprising: - a liquid hydrogen (LH 2) tank for LH 2 storage at cryogenic temperature, - LH 2 circulation pipes starting and ending at the LH 2 tank, - a first heat exchanger (36, 36a, 36b) configured to exchange heat between a first fluid and a second fluid, - a first cryostat of second fluid for cooling the motor control unit and the superconducting e-motor, - a second cryostat (50a, 50b) of second fluid for cooling the DC/DC converter, and - second fluid circulation pipes (42, 54a-k), starting and ending at each cryostat (38, 50a, 50b). - a liquid hydrogen (LH 2) tank for LH 2 storage at cryogenic temperature, - LH 2 circulation pipes starting and ending at the LH 2 tank, - a first heat exchanger (36, 36a, 36b) configured to exchange heat between a first fluid and a second fluid, - a first cryostat of second fluid for cooling the motor control unit and the superconducting e-motor, - a second cryostat (50a, 50b) of second fluid for cooling the DC/DC converter, and - second fluid circulation pipes (42, 54a-k), starting and ending at each cryostat (38, 50a, 50b).