中文摘要：

针对小天体撞击任务，应用VxWorks嵌入式实时操作系统，设计小天体高速撞击器的星载GNC软件部分．对星载GNC系统结构进行简要描述；在此基础上，综合考虑小天体撞击任务的实时性要求、不同飞行模式的耦合关系、轨道确定的数学运算量以及对不同敏感器数据采集的周期性控制等多方面因素，对小天体撞击任务进行模块化分解，提出各个任务模块间的同步方式与通信手段；在PC-104嵌入式计算机与dSPACE实时仿真平台的联合环境下，对所设计的星载GNC软件进行仿真验证，结果表明，基于VxWorks嵌入式实时操作系统所设计的小天体撞击GNC软件完全可以满足小天体撞击任务的实时性要求，为撞击任务的顺利进行提供有效的保证．

英文摘要：

An on-board GNC software system developed by using the real-time operation system （RTOS） VxWorks for a small celestial body impact mission is presented in this paper. First, the structure of on-board GNC system is described briefly. Then the system is decomposed into different task configuration modules in consideration of a variety of factors such as the realtime requirement of the small body impact mission, coupled relations between different flight modes, computational effort of orbit determination and periodic control for data acquisition of different sensors. In the meanwhile, it brings forward the method of communicational and synchronized modes the tasks. At last, the simulation is conducted to verify the on-board GNC software in the embedded computer PC-104 and the real-time simulation platform dSPACE.