Guidance, Control and Dynamics for Asteroid Exploration

目前，世界范围内对小行星和彗星等小天体的探索有很大的兴趣。这些天体为了解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，对这些天体的探索已经引起了人们几十年的兴趣，就像今天一样。***近年来，人类对近地小行星的探索和开发也越来越感兴趣。对NEA的人类探索任务被视为最终人类火星任务的中间步骤。此外，需要人类对小行星进行探索，以确定可以从小行星上开采哪些资源，以支持人类在太空中的存在。从保护地球免受潜在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方法来改变小行星与地球的碰撞路线。然而，要使这些方法中的任何一种取得成功，都需要充分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。在此背景下，本提案工作的目标是支持未来的小行星探测任务。具体而言，目标是：***(1)在小行星附近精确地建立轨道/姿态耦合航天器动力学模型。***(2)基于轨道/姿态耦合的航天器近小行星机动燃油效率制导控制律研究。***(3)开发一种利用轨道航天器的轨道和姿态测量估算小行星引力模型的方法。***(4)开发（由航天器）将巨石从近地小行星安全转移到月球轨道（在即将到来的NASA小行星重定向任务的背景下）的制导和控制律。**

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). **