In this paper, design and optimization approaches are applied to a hybrid-powered small-satellite launcher, namely a deterministic and a robust-based method. A unique hybrid rocket engine is considered, employed in different numbers in each stage of the three-stage launcher: six, three, and one, respectively, in the first, second, and third stage. Liquid oxygen and paraffin-based fuel are considered as propellant combination. A blowdown feed system is assumed to ensure system simplicity and reduce the overall launcher cost. An airborne launch is proposed at a given altitude and speed, whereas the velocity angle on the horizon at first stage ignition is set free. The optimization procedure of the engine design parameters employs a direct method and an evolutionary algorithm in the deterministic and robust-based approach, respectively. An indirect method is used to optimize the ascent trajectory, given the engine design, in both the approaches. In the robust-based approach, uncertainties in the fuel regression rate are taken into account. Small-launcher initial mass is given and payload mass is maximized for a given insertion orbit. A mission-specific objective function is used in the robust-based optimization process to grant the actual achievement of mission goals, despite the uncertainties in the design. Two different design strategies are compared. In the first case the acceleration at first-stage ignition is fixed, whereas in the second case the initial thrust is optimized. Results show that a 5-ton hybrid-rocket launcher can be viable for launch of satellites in the 50–100 kg range and that a small payload reduction, with respect to deterministic optimized solutions, is sufficient to ensure mission accomplishment and also grant the required design robustness.

在本文中，设计和优化方法应用于混合动力小型卫星发射器，即确定性和基于鲁棒性的方法。考虑了一种独特的混合火箭发动机，在三级发射器的每个阶段使用不同的数量：分别在第一、第二和第三级中使用六个、三个和一个。液氧和石蜡基燃料被认为是推进剂组合。假定使用排污系统以确保系统简单并降低总发射器成本。建议在给定的高度和速度下进行空中发射，而第一阶段点火时地平线上的速度角是自由的。发动机设计参数的优化程序分别在确定性和基于鲁棒性的方法中采用直接方法和进化算法。在这两种方法中，给定发动机设计，使用间接方法来优化上升轨迹。在基于稳健的方法中，燃料回归率的不确定性被考虑在内。对于给定的插入轨道，给出了小发射器的初始质量，并最大化了有效载荷质量。尽管设计存在不确定性，但在基于鲁棒性的优化过程中使用特定于任务的目标函数来授予任务目标的实际实现。比较了两种不同的设计策略。在第一种情况下，第一阶段点火时的加速度是固定的，而在第二种情况下，初始推力是优化的。结果表明，5 吨混合火箭发射器可用于发射 50-100 公斤范围内的卫星，并且相对于确定性优化解决方案，有效载荷减少很小，