2021 年 19 巻 6 号 p. 874-883
In this paper, the conceptual design of reusable winged suborbital vehicles with rocket propulsion is investigated considering two mission configurations: 1) the satellite-launch configuration in combination with an expendable upper stage and 2) the high-altitude suborbital-flight configuration in combination with an external payload carrier. It is expected that such a multi-purpose vehicle concept can save the total development cost of orbital and suborbital transportation systems. However, the transportation performance of the multi-purpose vehicle may be inferior to that of single-purpose vehicles specialized for specific missions, since the suited vehicle design depends on the mission trajectory. Considering this issue, this paper conducts multidisciplinary design optimization with two objectives for maximizing orbital and suborbital transportation performances. In order to optimize the vehicle design, the satellite-launch trajectory, and the suborbital flight trajectory in an integrated and efficient way, a decomposition-based multi-objective evolutionary algorithm and a gradient-based optimization method are applied to vehicle design and trajectory design, respectively, with a nested structure. The obtained solutions reveal the tradeoff characteristics of these two missions, and they provide some information on the feasibility of this multi-purpose vehicle concept.
