A stage of a space launcher including an engine core, a tank secured above the engine core, and a nozzle including a first deployable nozzle section secured below the engine core, the nozzle further including a second and a third section configured to be situated extending from each other when the nozzle is in a deployed propulsion configuration. The stage further includes a structure for temporarily supporting nozzle sections mounted on the tank, configured to change the nozzle to a configuration for accessing the engine core wherein the nozzle sections are inserted into each other, with the third section bearing against a lower support of the temporary structure.

An expandable exhaust cone assembly is described which is able to move from a collapsed position to an expanded position.

A divergent segment includes a stationary divergent portion and a movable divergent portion suitable for occupying a retracted position and a deployed position. The threaded rod has a head supported by a support secured to the stationary divergent portion in cooperation with a rotary drive for driving the threaded rod in rotation, and a tip suitable for being inserted in a holder sleeve secured to the stationary divergent portion. The threaded rod cooperates with a nut secured to the movable divergent portion so that rotation of the rod causes the movable divergent portion to move. The tip presents an enlargement having at least one groove passing axially therethrough.