单级入轨飞行器水平发射的优势

建立了可用于描述单级入轨飞行任务的动力学模型.选取了一种升力体外形的单级入轨飞行器作为算例,对水平发射的优势进行了论证.结合英国HOTOL的起飞参数对算例的水平发射过程进行了仿真,验证了地面助推发射对减少起飞段推进剂消耗的贡献.简要回顾并分析了美国X-33计划曾面临的技术困难,对算例在不同发射方式下所获得的入轨质量及其组成进行了比较,表明了降低起飞推重比对提高单级入轨飞行器运载效率的重要意义.选择相同的起飞参数,对采用不同发射方式时算例的飞行过程进行了对比.结果表明,水平起飞飞行器由于能够更好地利用其自身的升力体效应,在大气层内消耗的推进剂较垂直发射时少.

Advantages of Horizontal Take-off Single-Stage-to-Orbit Vehicles

A dynamic model was established to describe a Single-Stage-to-Orbit(SSTO) flight mission.A lift body SSTO vehicle was used to demonstrate the advantages of horizontal take-off.To validate the contributions of ground assisted take-off in reducing propellant consumption under the take-off phase,the horizontal take-off process of the vehicle was simulated applying some take-off parameters of the British HOTOL.Technical difficulties of the American X-33 were briefly reviewed and analyzed.In the case of different take-off methods,mass to orbit and its composition of the vehicle were compared.The results show that reducing the take-off thrust/weight ratio can significantly increase the launch efficiency of the SSTO vehicles.Flight progresses of the vehicle with different take-off approach were compared using the same take-off parameters.The comparisons indicate that the vehicle taking-off horizontally has a less propellant consumption in aerosphere than that taking-off vertically.That is because a horizontal take-off vehicle can make a better use of its lift body effectiveness,