Comet chaser mission moves from blueprint to reality
A new European Space Agency science mission, proposed by the UK, to 3D-map a comet for the first time has reached a major milestone, moving from the design phase to implementation.
Comet Interceptor mission
The Comet Interceptor mission, which will further our understanding of the evolution of comets and will help solve some of the mysteries of the Universe, has been formally adopted by the European Space Agency (ESA).
Due for launch in 2029, the mission will see one main spacecraft and two robotic probes travel to an as-yet unidentified comet and map it in three dimensions.
The mission was first proposed by an international team led by University College London’s Mullard Space Science Laboratory (MSSL) in Surrey and the University of Edinburgh.
Professor Colin Snodgrass, who is based at the University of Edinburgh’s Institute for Astronomy, was deputy lead on the proposal, and leads the target selection team that is working to identify suitable comets, commented:
It is very exciting to be part of a mission that follows a completely new approach: designing and building the spacecraft before the target is even discovered. This opens up opportunities to visit space objects that were completely inaccessible before, such as comets entering the inner solar system for the very first time, or possibly even interstellar objects that formed around a distant star.
The UK Space Agency has so far provided £2.3 million in funding for two instruments on the mission: The Modular InfraRed Molecules and Ices Sensor (MIRMIS) instrument is led by the University of Oxford. MIRMIS will deliver a unique dataset, providing information such as the comet’s shape, size and rotation state. The Fluxgate Magnetometer (FGM) sensor led by Imperial College London and located on the ESA probe will provide high accuracy and high-time resolution measurements of the comet’s magnetic field strength and direction. One of the two robotic probes will be built by the Japanese Space Agency, with the team working to find a contractor for the main spacecraft and the other robotic probe.
Understanding the origins of our Solar System
Comets are what is left over when a planetary system forms and in each ancient object is preserved information about the formation of the Solar System 4.6 billion years ago.
Comet Interceptor would be the first mission to travel to a comet which has never previously encountered the inner Solar System.
To do this, it will need to launch and reach a holding position around 1 million miles away from Earth. There it will lie in wait – possibly for years - until astronomers on the ground spot a suitable comet for it to intercept. The two probes will make closer passes of the comet’s nucleus and beam their data back to the main craft.
This new ambush tactic is the first of its kind. The fly-by of the three spacecraft, including the two probes, which measure less than a meter across, is likely to take just a few hours but could illuminate conditions that prevailed more than 4 billion years ago.
Previous missions have studied comets trapped in short-period orbits around the Sun, meaning they have been significantly altered by our star’s light and heat. Breaking from that mould, Comet Interceptor will target a pristine comet on its first approach to the Sun.
The scientists are likely to target a comet travelling from the Oort Cloud — a band of icy debris that lies about halfway between the Sun and the next nearest star.
This debris was formed during the conception of the Solar System but was rapidly ejected to its outermost edge. Unlike more familiar comets, their surface will not have been vaporised by the Sun’s energy — a process that leads to dust building up on a comet, obscuring its original state.
Once the probes reach a pristine comet, they will study and scrutinise the chemical composition of it, with one aim being to evaluate whether similar objects may have brought water to planet Earth in the past.