Virgin Galactic has completed a major milestone in the build of the next spaceship in its fleet. The team has placed the Main Oxidiser Tank (MOT) into the fuselage – moving this vehicle a step closer to beginning its flight test program.
The MOT forms part of the structure of the vehicle, connecting the forward and aft part of the spaceship. It also holds the oxidiser for the rocket motor which powers the spaceship to space. The Virgin Galactic rocket motor is a hybrid system which uses a solid fuel along with a liquid oxidiser and holds the record of being the most powerful hybrid rocket motor to be used in crewed flight. During a spaceflight, the oxidiser in the MOT allows the solid fuel to burn.
“To ignite the rocket motor and burn the fuel an oxidiser is needed,” explains Jose Stevens, Chief Engineer, Propulsion, at The Spaceship Company. “On Earth, most fuel burns using the plentiful supply of oxygen found in the atmosphere, but at very high altitudes and in space, the lack of oxygen means we have to bring an oxidiser along with us to allow the rocket motor fuel to burn and generate the required thrust.”
During the most recent Virgin Galactic spaceflight, the rocket motor burned for a duration of 60 seconds and created enough energy to propel the spaceship, VSS Unity, into space at almost three times the speed of sound.