 | |
| Mission type | Comet flyby |
|---|---|
| Operator | ESA /JAXA |
| Website | www |
| Mission duration | ≈ 5 years |
| Spacecraft properties | |
| Spacecraft | Comet Interceptor |
| Launch mass | Approx. 850 kg (1,870 lb).[1] |
| Start of mission | |
| Launch date | 2029 (planned)[2] |
| Rocket | Ariane 62 |
| Launch site | KourouELA-4 |
| Contractor | Arianespace |
| Flyby of along-period comet yet to be selected | |
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Comet Interceptor is a robotic spacecraft mission led by theEuropean Space Agency (ESA) planned for launch in 2029.[2] The spacecraft will be placed at theSun-Earth L2 point and wait for up to three years for along-period comet to fly by at a reachable trajectory and speed. The mission's primary science goal is "to characterise a dynamically-newcomet including its surface composition, shape, structure, and the composition of its gascoma."[3]
Comet Interceptor is being developed as ESA's first Fast class (F-class) of theCosmic Vision programme. The mission is being planned and developed by a consortium that includes the ESA and Japan's space agencyJAXA.Comet Interceptor will share the launch vehicle with ESA'sARIEL space telescope, which is also bound for Lagrange point 2.[2] ThePrincipal Investigator is Geraint Jones, from theMullard Space Science Laboratory in theUnited Kingdom. The maximum cost of thespacecraft bus is set at €150M, excluding science instruments and launch services.[1]
Long-period comets have highly eccentric orbits and periods ranging from 200 years to millions of years,[4] so they are usually discovered only months before they pass through the inner Solar System and return to the distant reaches of the outer Solar System, which is too little time to plan and launch a mission. Therefore, ESA will "park" theComet Interceptor spacecraft on a stablehalo orbit around theSun-Earth L2 point and wait for the discovery of a suitable comet that it can reach for a closeflyby.[5]
TheComet Interceptor mission is unique in that it is designed to encounter an as-yet unknown target, having to wait between 2 and 3 years for a target it can reach with a reasonable change in velocity (delta-v) within a total mission length of approximately 5 years.[5][6] The baseline design issolar electric propulsion.[5]
Finding a suitable comet to fly by will rely on ground-based observational surveys such asPan-STARRS,ATLAS, or the futureVera C. Rubin Observatory's Legacy Survey of Space and Time (LSST).[1] In the case that no long-period comet can be intercepted in time, a backup short period comet (baseline:73P/Schwassmann–Wachmann) can be studied.[5] There is also the potential of intercepting aninterstellar object passing through the Solar System, if the speed and direction permit.[5][7][8]
One-two days before the comet flyby, the main spacecraft (spacecraft A) will deploy two small probes (B1 and B2) to venture even closer to the target, carrying complementary instrument payloads and to sample thecoma.[9][10] Each of the three spacecraft will sample gas composition, dust flux, density, magnetic fields, andplasma andsolar wind interactions, to build up a 3D profile of the region around the comet.[11]
| Spacecraft element | Agency | Science payload[12] |
|---|---|---|
| A | ESA | CoCa: Visible/near-infrared imager MANIaC: Mass Analyzer for Neutrals and Ions at Comets (mass spectrometer) MIRMIS: NIR and Thermal IR spectral imagers, and MIR spectrometer DFP: Dust, Fields and Plasma |
| B1 | JAXA | HI:Lyman-alpha Hydrogen imager PS:Plasma Suite WAC: wide angle camera |
| B2 | ESA | OPIC: Optical Imager for Comets (Vis/IR) EnVisS: Entire Visible Sky coma mapper DFP: Dust, Fields and Plasma |
In 2019,Comet Interceptor has been selected as ESA’s newFast-class mission.[13][14] In June 2022, the mission was adopted by ESA during the Agency’s Science Programme Committee.[15][16] In December 2022, ESA andOHB have signed a contract to move forward with the design and construction of the spacecraft.[17] In 2023, theEstonian Space Office decided to support the development of OPIC, a camera system designed by theUniversity of Tartu.[18][19] In September 2024, MMA Space was selected to provide solar panels for the Probe B1.[20][21]
In July 2024, the spacecraft's magnetometer boom was undergoing vibration testing[22] In November 2024, the Probe B2’s structural qualification model passed all mechanical tests and was pronounced structurally sound.[23] In December 2024, OHB Czechspace inBrno,Czechia assembled a testing article of the dust shield before transporting it toIABG test facilities in Germany.[24][25]
In May 2025, ESA received results of theLatvian project CI3D — photorealistic computer-generated images that will be used for testing the spacecraft's cameras under various conditions around the unknown target body.[26]Redwire Corporation has also delivered the spacecraft's flight computer.[27]
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