Optical Periscopic Imager for Comets (OPIC)

Comet Interceptor mission

OPIC is an instrument for the Comet Interceptor ESA F-class mission http://www.cometinterceptor.space/. The mission's goal is to visit a dynamically new object, entering the inner solar system for the first time to explore such object for the first time during mankind's history.

The mision consists of three spacecraft: spacecraft A, spacecraft B1 (from ESA), and spacecraft B2 (from JAXA). B1 and B2 spacecraft will separate from A before the encounter and travel closer to the nucleus (baseline around 400 km closest distance).

Views from A and B2 spacecraft during interception


Possible targets

Main: A dynamically new comet


A dynamically new comet is a comet from the edge of the solar system (such as Öpik-Oort cloud). An example of a possible dynamically new comet is comet ISON (image credit: TRAPPIST/E. Jehin/ESO, see original). Such comets are in their pristine state since their formation during the early days of the solar system and they carry clues about the conditions in the early solar system, clues about the origin of organics and water, and possibly even clues about the origin of life.

Ideal: Interstellar object


Interstellar objects, like 'Oumuamua (artist impression shown, image credit: ESO/M. Kornmesser,  see original). Such objects originate from other planetary systems (exoplanetary systems) and are our first possible options to see a part of a different planetary system and to understand processes in those. According to a theory called panspermia, such objects could also carry primitive organisms and seed life in the galaxy.

Backup: Regular asteroid or comet

Fragmenting comet 73P

Should a situation arise where visiting primary targets becomes infeasible, another target will be selected from a list of bodies with well characterized orbits and that are of scientific interest. One such classes of objects are fragmenting comets, such as Comet 73P/Schwassmann-Wachmann (Credit: NASA, ESA, H. Weaver (APL/JHU), M. Mutchler and Z. Levay (STScI)  see original)


The instrument is a specialized camera on the B2 spacecraft to take images of the nucleus and the dust around it. As subspacecraft B2 will be spinning, the image of the nucleus will rotate on the camera frame.

Opic instrument and its placement

OPIC schematic

OPIC is a monochrome periscopic camera.


OPIC will be positioned to face the comet nucleus.

Expected datastream


The instrument is being built in Tartu Observatory, University of Tartu and most hardware developments will take place in Tartu Observatory. OPIC's Principal Investigator is Dr. Mihkel Pajusalu. Some B2 related activities, mainly relating to science and data processing will be carried out in Aalto University, Finland, under supervision of Dr. Andris Slavinskis.