NUMERICAL STUDY ON THE FIRST-STAGE RE-ENTRY TRAJECTORY USING AN INFLATABLE BALLUTE

This article proposes the use of inflatable ballutes to decelerate the first stage of a launcher during its reentry phase and to allow its recovery. In recent years, reusable launch vehicles (RLVs) have been proposed to significantly reduce the costs of space missions. The most famous case is the Falcon-9 first stage reused dozens of times. In this case the deceleration is producted by the propulsion system of the stage that is turned on during the re-entry. To evaluate the use of inflatable ballutes as an alternative braking systems, CFD simulations were performed using the conjugate heat transfer (CHT) technique. This technique allows to evaluate the drag and the heating caused by the high speed and by the exhaust gases of the propuslion system. The results show that the use of the inflatable ballutes decelerates much more than the use of retropropulsion reducing the amount of the necessary propellant and can reduce the heating of the side wall of the reusable stage during the descent.