Flight Power Modeling of VTOL Aircraft for Exploration of Titan

Flight power and energy requirement models were developed for Titan Aerial Daughtercraft (TAD) mission concepts, in which a small-scale (e.g. ≤ 10 kg) VTOL aircraft would conduct multiple sorties on Titan from a mothership (lander or balloon), recharging batteries from a radioisotope power source (RPS) on the mothership between sorties. The current study considers two design configurations for the TAD, a quadcopter and a tailsitter, and examines potential flight duration and range for lander-based scenarios, as well as allowable payload mass fraction and surface exploration range for balloon-based scenarios. To quantitatively compare the performance of these different configurations, a conceptual design analysis was developed. In a lander-based scenario, assuming a payload mass fraction of 25 percent and a conservative battery model, the estimated flight endurance at Titan's surface for a 10 kg quadcopter and tailsitter was estimated to be 7.6 hours and 11.7 hours respectively. Maximum flight radius from a lander across Titan's surface was found to be 82 km and 108 km, respectively. Modeling of balloon-based scenarios estimated allowable payload mass as a function of the total TAD mass and the float altitude of the balloon. For a balloon floating at 10 km altitude and a 10 kg TAD, the model estimated available payload mass of about 2.8 kg for a quadcopter and 3.5 kg for a tailsitter. The possible exploration range for the same balloon altitude and TAD system mass was computed to be 42 km for a quadcopter and 65 km for a tailsitter. The information estimated in the current mission analysis would yield initial insight for the entire mission architecture design; for example, selection of a landing point or balloon altitude that enables efficient and effective scientific activities over diverse surface features on the biggest moon of Saturn.