The Comet Interceptor mission was officially adopted by the European Space Agency (ESA) at a meeting in Madrid today (Wednesday 8 June 2022), moving from the design phase to implementation, with the next step to select a contractor to build the spacecraft and a robotic probe.

Due for launch in 2029, it will see a main spacecraft and two robotic probes – the other built by the Japanese Space Agency (JAXA) – travel to an as yet unidentified comet and map it in three dimensions.

Caroline Harper, Head of Space Science at the UK Space Agency, said:

This is an important milestone for the Comet Interceptor mission. After an intensive period of work on the feasibility and definition of the mission design, we are ready to move to the full implementation stage.

Comet Interceptor will not only deepen our understanding of comet evolution, but also help unravel the mysteries of the Universe.

The mission was first proposed by an international team led by the Mullard Space Science Laboratory (MSSL) at University College London in Surrey and the University of Edinburgh.

Professor Geraint Jones, from the UCL Mullard Space Science Laboratory, said:

We should get our first glimpse of a truly pristine body with this mission – a priceless example of the objects that came together to form Earth and other planets. The comet’s surface will be largely unchanged since the formation of the solar system billions of years ago, and I look forward to seeing this uncharted territory in the 2030s.

It’s fantastic to have got the go-ahead for the mission after almost four years of hard work since the publication of the invitation to propose from the European Space Agency. The international team of scientists and engineers, together with colleagues from ESA, kept the development of the mission on track despite the many complications raised by Covid-19.

Professor Colin Snodgrass, from the University of Edinburgh, added:

It’s very exciting to be part of a mission that follows a completely new approach: designing and building the spacecraft even before the target is discovered. This opens up possibilities to visit space objects that were completely inaccessible before, like comets entering the inner solar system for the very first time, or perhaps 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 provide a unique dataset, providing information such as the comet’s shape, size and rotational state. The Fluxgate Magnetometer (FGM) sensor led by Imperial College London will provide high-accuracy, high-time-resolution measurements of the size and direction of the comet’s magnetic field.

Professor Neil Bowles, from the University of Oxford, said:

In collaboration with our Finnish colleagues, MIRMIS will observe Comet Interceptor’s core at infrared wavelengths particularly sensitive to temperature and composition, mapping the core material in what may be the first close encounter of the Comet Interceptor. object with the Sun. Combined with data from the other Comet Interceptor instruments and probes, this will provide a unique snapshot of a potentially very old object.

By exploring comets, we learn the origins of our solar system

Comets are what is left 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 visit a comet that has never encountered the inner solar system before.

To do this, it will have to launch and reach a ready position about a million kilometers from Earth. There it will wait – perhaps for years – until astronomers on the ground spot a suitable comet to intercept. The two probes will make closer passes of the comet’s nucleus and transmit their data to the main craft.

This new ambush tactic is the first of its kind. The flyby of the three spacecraft, including the two probes, which measure less than a meter in diameter, is expected to take only a few hours but could shed light on conditions that prevailed more than 4 billion years ago.

Previous missions have studied comets trapped in short-period orbits around the Sun, which means they have been significantly altered by light and heat from our star. Breaking out of this mold, Comet Interceptor will target a virgin comet on its first approach to the Sun.

Scientists will likely target a comet traveling from the Oort Cloud – a band of icy debris that lies halfway between the Sun and the next closest star.

This debris formed during the conception of the solar system but was quickly ejected towards its outermost edge. Unlike more familiar comets, their surfaces will not have been vaporized by energy from the Sun – a process that leads to dust accumulating on a comet, obscuring its original state.

Once the probes reach a pristine comet, they will study and scrutinize its chemical composition, with one goal being to assess whether similar objects may have brought water to planet Earth in the past. .