Mission Concept for the Exploration of Interstellar Bodies

Since the discovery of ’Oumuamua and Borisov in 2017 and 2019 respectively, a novel interstellar object has yet to be encountered. The priceless scientific returns of previous missions to long-period comets are unquestioned. However, these disruptive undertakings have all targeted bodies that have periodically approached the sun, and therefore experienced many chemical and physical modifications which would hinder our understanding of the origins of the Solar System. In December 1984, the Vega 1 and Vega 2 spacecraft were launched by the Soviet Space Program to perform a swing-by of Venus and a flyby of Comet Halley. Due to a dust protection problem, the position of Vega 1 relative to the nucleus of Comet Halley could only be estimated to be in the range of a few thousand kilometers. However, despite many technical challenges, the mission marked the first attempt to get closer to a long-period comet to collect data about its nucleus, dust production rate, chemical composition, and rotational rate, also paving the way for future ESA mission Giotto. Comet Halley would be revisited by the National Aerospace Laboratory of Japan (NAL) only two days later, on March 8th, 1986, with the Sakigate, or "Pioneer" mission. With only three instruments, it was able to study the comet’s plasma wave spectra, solar wind ions, and interplanetary magnetic fields. Fast forward to 1998, Deep Space 1 (DS1) represented the first of a series of technology demonstration probes developed by NASA as part of its Millenium Program. To be tested was the Miniature Integrated Camera Spectrometer (MICAS), a new technology capable of combining imaging channels with UV and IR spectrometers to further our understanding of Comet Barrelly’s chemical composition, geomorphology, spin-state, atmosphere, and size. A Plasma Experiment for Planetary Exploration (PEPE) was also on board to measure the solar wind during the cruise phase of the mission, along with the interaction of the solar wind with target bodies during the encounters and the composition of the cometary coma. All three missions featured an interceptor as the only spacecraft sent to perform the different analyses on the different target bodies. Recent and continuous technological advancements have made it possible to optimize the efficiency and accuracy of the data collected during the different phases of a mission. It is nowpossible to combine a variety of modules on a single spacecraft so that different experiments can be executed with minimal risk while maximizing the scientific return. Impactor missions involve performing a ballistic collision with the target body to separate materials from the main surface. These can be observed, analyzed, or collected by a different module of the spacecraft that might be orbiting around the impact site or observing the event from a safe distance. In this work, we explore a mission concept that would allow us to take advantage of the high relative velocity between the spacecraft and the target interstellar body to study its topology, chemical composition, and other critical parameters of scientific interest. The mission will rely on being able to monitor any possible interstellar bodies that are coming into contact with our solar system to allow us to "launch on detection". Such an endeavor is being attempted by ESA’s new F-class Comet Interceptor mission. The premises for this mission are that the only way to encounter dynamically new interstellar objects is to become aware of them with a sufficiently long time warning to direct a spacecraft towards them. The long-period comets and interstellar objects that have been discovered so far reveal a very short time interval between their discovery, perihelion and departure from the Solar System. The range varies between a few months to a year, rendering a mission’s planning, launch, and execution very arduous. Comet Interceptor will be acting as a space sentinel while parked at the Sun-Earth Lagrange Point L2, enabling a faster planning phase for future missions interested in interstellar objects and long-period comets. Furthermore, we aim to perform trajectory simulations and analytical calculations such as overall feasibility determination, and a detailed study of the different phases that will constitute the primary mission objective.