Here we describe the novel, multi-point Comet Interceptor mission. It is dedicated to the exploration of a little-processed long-period comet, possibly entering the inner Solar System for the first time, or to encounter an interstellar object originating at another star. The objectives of the mission are to address the following questions: What are the surface composition, shape, morphology, and structure of the target object? What is the composition of the gas and dust in the coma, its connection to the nucleus, and the nature of its interaction with the solar wind? The mission was proposed to the European Space Agency in 2018, and formally adopted by the agency in June 2022, for launch in 2029 together with the Ariel mission. Comet Interceptor will take advantage of the opportunity presented by ESA’s F-Class call for fast, flexible, low-cost missions to which it was proposed. The call required a launch to a halo orbit around the Sun-Earth L2 point. The mission can take advantage of this placement to wait for the discovery of a suitable comet reachable with its minimum \(\varDelta \)V capability of \(600\text{ ms}^{-1}\). Comet Interceptor will be unique in encountering and studying, at a nominal closest approach distance of 1000 km, a comet that represents a near-pristine sample of material from the formation of the Solar System. It will also add a capability that no previous cometary mission has had, which is to deploy two sub-probes – B1, provided by the Japanese space agency, JAXA, and B2 – that will follow different trajectories through the coma. While the main probe passes at a nominal 1000 km distance, probes B1 and B2 will follow different chords through the coma at distances of 850 km and 400 km, respectively. The result will be unique, simultaneous, spatially resolved information of the 3-dimensional properties of the target comet and its interaction with the space environment. We present the mission’s science background leading to these objectives, as well as an overview of the scientific instruments, mission design, and schedule.

在这里，我们描述了新颖的多点彗星拦截器任务。它致力于探索一颗很少加工的长周期彗星，可能是第一次进入太阳系内部，或者遇到源自另一颗恒星的星际天体。该任务的目标是解决以下问题：目标物体的表面成分、形状、形态和结构是什么？彗发中的气体和尘埃的成分是什么，它与原子核的联系，以及它与太阳风相互作用的性质是什么？该任务于 2018 年向欧洲航天局提出，并于 2022 年 6 月被该机构正式采用，将于 2029 年与 Ariel 任务一起发射。Comet Interceptor 将利用 ESA 的 F 级呼叫提供的机会，执行其提议的快速、灵活、低成本的任务。该呼叫需要发射到围绕日地 L2 点的光晕轨道。该任务可以利用这个位置来等待发现一颗合适的彗星，其最小 \（600\text{ ms}^{-1}\） 的能力可以到达。彗星拦截器在标称最近接近距离 1000 公里处遇到和研究一颗彗星方面将是独一无二的，这颗彗星代表了太阳系形成过程中近乎原始的物质样本。它还将增加一项以前彗星任务所没有的能力，即部署两个子探测器——由日本航天局 JAXA 提供的 B1 和 B2——它们将沿着不同的轨迹穿过彗发。当主探测器以 1000 公里的标称距离通过时，探测器 B1 和 B2 将分别在 850 公里和 400 公里的距离上通过彗发，跟随不同的弦。 结果将是目标彗星的 3 维特性及其与空间环境相互作用的唯一、同步、空间分辨信息。我们介绍了导致这些目标的任务的科学背景，以及科学仪器、任务设计和时间表的概述。