Assessment of the Efficiency of Hot Helium Tank Pressurization Systems for Oxygen-Propelled Rocket Engines

For the first time, a study of the d esign has been conducted, and a detailed weight summary of the hot helium pressurization system for an oxidizer tank of the first stage of a launch vehicle (LV) has been presented; the propulsion system of this LV uses boiling oxygen — RG-1 as propellants. The oxidizing generator gas was considered as the heat exchanger heat carrier. The weight of this system was also evaluated for an alternative common heat carrier — reduced generator gas. A good correlation was shown between the obtained results and known data from other pressurization systems. The efficiency of hot helium pressurization systems is demonstrated in the case of multiple reuses of the first stage of an LV. It is also reasonable to use it for the dual activation of the liquid rocket engine (LRE) of the second stage of an LV. In these cases, arising issues are solved using well-established, proven solutions. However, an analysis of technical literature shows that alternative solutions have not been thoroughly studied. In other cases, considering the high cost, structural complexity, actual low reliability, and lack of weight advantages, the use of hot helium pressurization systems is hardly justified. This primarily concerns LREs with afterburning of generator gas, where oxidizing gas is used as the coolant in the heat exchanger.