DEVICE FOR SELF-PRESSURIZATION OF A TANK

1 . A propulsion assembly for a rocket, comprising a tank configured to contain a propellant, an engine having a combustion chamber, a propellant feed pipe extending between the tank and the combustion chamber and having an isolation valve arranged therein, and a heater having an inlet connected to the feed pipe and an outlet connected to the tank, wherein the inlet of the heater comprises an inlet pipe connected firstly to the feed pipe downstream from the isolation valve and secondly to a neutral fluid feed.

2 . A propulsion assembly according to claim 1 , comprising means configured to maintain the neutral fluid in the neutral fluid feed at a pressure that is not less than the critical pressure of the propellant.

3 . A propulsion assembly according to claim 1 , wherein the neutral fluid feed comprises a check valve allowing fluid to flow in the feed only in the direction going towards the heater.

4 . A propulsion assembly according to claim 1 , comprising means for sweeping an injection head of the combustion chamber with the neutral fluid.

5 . A propulsion assembly according to claim 1 , wherein the neutral fluid is helium.

6 . A propulsion assembly according to claim 1 , wherein the propellant is oxygen.

7 . A propulsion assembly according to claim 1 , wherein the heater is a heat exchanger that co-operates with a pipe transporting another propellant.

8 . A propulsion assembly according to claim 1 , wherein the heater is a heat exchanger that co-operates with a pipe transporting combustion gases.