ESA unveils new mission 'Comet Interceptor' to scrutinise inner solar system's space rocks

The European Space Agency (ESA), on June 8, unveiled its new mission named 'Comet Interceptor,' which would scrutinise a comet that once lingered in inner solar system or is new to it. This mission was proposed in July 2018 and has now been adopted after the completion of its study phase. ESA revealed that it will soon begin the development of the mission after selecting a prime contractor for a spacecraft. 

When will mission Comet Interceptor launch?

The Comet Interceptor spacecraft will be launched in 2029 in a ride-share mission with ESA's Ariel (Atmospheric Remote-sensing Infrared Exoplanet Large-survey) probe. Ariel is being designed to study the formation and evolution of exoplanets by surveying a diverse sample of about 1000 extrasolar planets, simultaneously in visible and infrared wavelengths. Notably, Ariel would be the first mission dedicated to measuring the chemical composition and thermal structures of exoplanets.

As for Comet Interceptor, it is a ‘fast’ or F-class mission, which weighs less than 1000 kg and takes only about eight years from adoption to launch. Once launched, both Interceptor and Ariel will be sent at the second Lagrange point (L2), which is 1.5 million km behind the Earth as viewed from the sun. 

Mission profile

The Interceptor spacecraft will be installed at L2 to spot and select a comet that has spent some time in inner solar system. The Interceptor will be made of three components -- the main spacecraft and two smaller probes. While one of the probes will be developed by ESA, the other will be a contribution by the Japan Aerospace Exploration Agency (JAXA). 

After Interceptor spots a target, it will release the two probes to extract information about the nature of the target comet through their multiple high-tech instruments. During the entire course of the mission, Interceptor will characterise the target's surface composition, shape and structure for the first time ever, and investigate the composition of its gas and dust. ESA says that this mission will build on the progress of its Rosetta and Giotto probes that visited ‘short-period’ comets.

The agency also highlighted that while Rosetta's target emerged from the rocky Kuiper Belt just beyond Neptune, Interceptor's target could hail from the Oort cloud, which is far beyond our solar system. Scientists believe that studying a target from outside our solar system would offer the chance to explore how comet-like bodies form and evolve in other star systems.

(Kuiper belt and Oort cloud illustration; Image: ESA)