Guidance, Control and Dynamics for Asteroid Exploration

目前，全世界对探索小行星和彗星等小天体都很感兴趣。这些天体为行星的形成以及太阳系本身提供了关键的见解。因此，从科学的角度来看，对这些天体的探索几十年来一直很有意义，就像今天一样。* 近年来，近地小行星也越来越引起人类探索和利用的兴趣。对近地小天体的载人探测使命被视为最终载人火星使命的中间步骤。此外，需要对小行星进行人类探索，以确定可以从小行星开采哪些资源，以支持人类在空间的存在。从保护地球免受可能的小行星撞击的角度来看，这种探索也很重要。越来越多的研究工作集中在开发使小行星偏离与地球碰撞轨道的方法上。然而，要使这些方法取得成功，就需要很好地了解小行星的物理特性（如质量、表面和结构特性）。对小行星的探索对于获得这种理解至关重要。* 在这方面，本提案中的工作目标是支持未来的小行星探索飞行任务。具体而言，目标是：*（1）对小行星附近的轨道/姿态航天器耦合动力学进行精确的动力学建模。* （2）利用轨道/姿态耦合，为航天器在小行星附近机动制订燃料效率高的制导和控制律。* （3）开发一种利用轨道航天器的轨道和姿态测量值进行小行星重力模型估计的方法。* （4）制定（由航天器）将一块巨石从近地小行星安全转移到月球轨道的制导和控制法（在美国航天局即将进行的小行星重定向使命范围内）。**

There is currently significant worldwide interest in the exploration of small celestial bodies, such as asteroids and comets. These bodies provide key insights into the formation of planets, as well as the solar system itself. Thus, from a scientific point of view, the exploration of these bodies has been of interest for several decades, just as they are today. ***In more recent years, Near-Earth asteroids (NEAs) have become of increasing interest for human exploration and exploitation as well. A human exploration mission to a NEA is viewed as an intermediate step towards an eventual human mission to Mars. Furthermore, human exploration of asteroids is needed to identify what resources could be mined from asteroids in order to support a human presence in space. Such exploration is also important from the point of view of protecting Earth from potential asteroid impact. There have been an increasing number of research efforts focusing on developing methods to deflect asteroids on a collision course with Earth. However, for any of these methods to be successful, the physical properties of asteroids (such as mass, surface and structural properties) need to be well understood. The exploration of asteroids is essential for gaining this understanding. ***Within this context, the objectives of the work in this proposal are in support of future asteroid exploration missions. Specifically, the objectives are: ***(1) Accurate dynamical modelling of the coupled orbital/attitude spacecraft dynamics in close proximity of asteroids. ***(2) Development of fuel efficient guidance and control laws for spacecraft maneuvering in close proximity of asteroids, exploiting the orbital/attitude coupling. ***(3) Development of a method for gravitational model estimation of asteroids utilizing orbit and attitude measurements of an orbiting spacecraft. ***(4) Development of guidance and control laws for the safe transfer (by a spacecraft) of a boulder from a Near Earth Asteroid to a lunar orbit (within the context of the upcoming NASA Asteroid Redirect Mission). **