Autonomous Spacecraft Proximity Operations with Uncooperative Resident Space Objects

最近的一项研究确定，未来10年将发射1200多颗卫星，这些卫星的制造和实施收入预计将达到1940亿美元。虽然大多数卫星不会出现重大问题，但统计数据预测，少数但数量可观的卫星将出现在轨异常或各种严重故障，给政府和私人组织造成数十亿美元的损失。许多研究表明，对这种驻留空间物体（RSO）进行近距离操作（目视检查、接近、交会和对接、捕获、服务/维修）可以节省大量费用。为了使这些近距离作战可行，机载能力必须在传统任务的基础上得到改进，这意味着自主性的显著增强，以及高度精确的相对弹道制导和控制。这些挑战在实际情况下会变得更加复杂，因为由于机械或电气故障，或燃料耗尽，目标RSO可能会不合作，在某种意义上说，它可能以未知的角速度旋转，没有通信能力，形状不确定，或具有未知的物理参数（质量和质量惯性矩）。此外，未建模的轨道扰动干扰了航天器的相对运动，可能影响航天器安全进行精确机动的能力。该研究计划的主要目标是开发非线性制导和自适应控制系统，使自主航天器接近操作具有非合作RSO。具体而言，将开发非线性制导和自适应控制系统，分别负责计算和跟踪相对于非合作RSO的期望相对轨迹。这些系统将在卡尔顿的航天器近距离操作试验台进行实验验证，该试验台由空气轴承自由浮动嵌入式航天器平台组成，能够在实验室环境中执行自主制导和控制机动。由于采用了新的制导和控制方法，本研究将提高运动跟踪精度和增强鲁棒性；从而促进机器人航天器与其不确定环境之间的无缝交互，这是由于需要执行非合作RSO的近距离操作而产生的。鉴于加拿大对这种复杂空间操作的兴趣日益增加，这项研究将使加拿大民用和军事空间组织（如加拿大国防研究与发展部、加拿大武装部队和加拿大航天局）在这些技术的最前沿，在全球空间市场的这个利基市场上。作为一个额外的好处，所开发的技术可以促进在未知或具有挑战性的环境中操作的其他智能航空航天代理（如自主无人机和无人驾驶飞行器）的类似算法的开发。

A recent study determined that more than 1,200 satellites will be launched over the next 10 years, and revenues from the manufacture and implementation of these satellites is expected to reach $194 billion. While most will perform without major problems, statistics predict that a small but significant number will experience on-orbit anomalies or failures of various severity, resulting in losses of billions of dollars for governments and private organizations. As demonstrated by numerous studies, performing proximity operations (visual inspection, approach, rendezvous and docking, and capture, service/repair) with such Resident Space Objects (RSO) could achieve substantial savings. To make those proximity operations feasible, the on-board capabilities must be improved over traditional missions, which means significantly increased autonomy, and highly accurate relative trajectory guidance and control. These challenges are further complicated in practical situations because, due to mechanical or electrical failures, or fuel depletion, the target RSO will likely be uncooperative, in the sense that it could be rotating at an unknown angular rate, have no communication capabilities, be of an uncertain shape, or have unknown physical parameters (mass and mass moments of inertia). Moreover, un-modeled orbital perturbations disturbing the relative motion of the spacecraft may impact the capability to perform accurate maneuvers safely. The main objective of this research program is to develop nonlinear guidance and adaptive control systems enabling autonomous spacecraft proximity operations with uncooperative RSO. Specifically, nonlinear guidance and adaptive control systems, respectively responsible to calculate and track the desired relative trajectory with respect to an uncooperative RSO, will be developed. These systems will be experimentally validated at Carleton's Spacecraft Proximity Operations Testbed, which consists of air-bearing free-floating embedded spacecraft platforms capable of performing autonomous guidance and control maneuvers in a laboratory environment. Thanks to the new guidance and control methods, the proposed research will lead to higher motion tracking accuracy and enhanced robustness; thereby facilitating seamless interactions between a robotic spacecraft and its uncertain environment, which arises from the need to execute proximity operations with uncooperative RSO. Given the increasing interests in such complex space operations in Canada, this research will place civil and military Canadian space organizations (such as Defence Research and Development Canada, Canadian Armed Forces, and Canadian Space Agency) at the forefront of these technologies, in this niche of the global space market. As an added benefit, the techniques developed may foster the development of similar algorithms for other intelligent aerospace agents operating in unknown or challenging environment, such as autonomous drones and unmanned aerial vehicles.