Recovery of Spent Stage of Reusable Launch Vehicle on a Droneship

Reusable Launch Vehicle (RLV) is more appealing to current space exploration institutes than conventional launch vehicles. RLVs can be utilised for numerous launches, which lowers launch costs and increases participation in space research initiatives. The reentry flight is regarded as the most important stage of RLV operation. In this study, GEKKO numerical optimization is used to find a reentry landing trajectory for a reusable launch vehicle that uses the least amount of fuel. Here, powered descent is the preferred option, where the reentry trajectory is optimised by controlling the thrust level. The bangbang control technique is used in thrust control. The three phases of the ideal trajectory are the boostback burn phase, the coasting or freefall phase, and the landing phase. The thrust direction and throttle level during these three phases are already predetermined to maintain the minimum fuel optimal trajectory. The reentry landing is executed for three different terminal cases that is unspecified downrange landing, specified downrange landing and return to launch site landing.