OPIC instrument for Comet Interceptor

The instrumentation of ESA's Comet Interceptor mission contains the Optical Periscopic Imager for Comets (OPIC), provided by the University of Tartu, Estonia. OPIC is the first Estonian instrument onboard an ESA Solar System exploration mission.

Comet Interceptor in an ESA F-class mission aiming to fly by a long-period comet visiting the inner Solar System, or an interstellar object like ‘Oumuamua that flew past the Sun in 2017. Scheduled for launch in 2029, Comet Interceptor will be parked in the Sun-Earth Lagrange point L2, waiting for up till 5 years until a suitable target object has been detected and chosen.

In addition to the primary spacecraft, provided by ESA, Comet Interceptor comprises two smaller probes: B1 provided by the Japanese Space Agency JAXA and B2 provided by ESA. The probes will be separated circa one day before the encounter with the target object, performing closer fly-bys than the primary spacecraft. The probes will hence face a higher risk of impacts by micrometeorites and dust particles in case the target object is an active comet. To mitigate the risk of data loss, the probes will continuously transmit measurement data to the primary spacecraft during the fly-by.

OPIC is a part of the payload of probe B2. It is a monochrome visual range camera taking images in the direction of travel. To avoid micrometeorites to directly impact the optics of OPIC, the instrument is pointed perpendicular to the flight direction and a periscope is used to align its field of view with the translation direction of probe B2.

The Field of View of OPIC, spanning 18.3 x 18.3°, scans the area around the target object with the rotation of the probe. Images taken far from the target are used to characterize gas and dust surrounding the object. Close to the target the firmware of OPIC prioritizes and crops the images to be transmitted to the primary spacecraft, to ascertain that the target is visible in the acquired data. Combined with images taken by the two other spacecraft of the mission, these data are used to construct a 3D model of the object and its potential dust jets.

OPIC is developed and tested by Tartu Observatory, institute of the University of Tartu. The instrument’s Principal Investigator is Dr. Mihkel Pajusalu. The flight and qualification models of the instrument are implemented by the industrial partner CrystalSpace OÜ (Estonia). The image prioritizing and cropping code is developed by Bitlake Technologies Ltd. (Latvia). Aalto University (Finland) participates in science planning and data processing.

The presentation summarizes the technical implementation of the OPIC instrument and the status of the project.