Comet Interceptor

The mission

Comet Interceptor (Figure 1) is the first ESA F-class (fast) mission part of the Cosmic Vision Programme, with a target launch date by 2028. The satellite consists in three spacecraft (S/C A, S/C B1 and S/C B2) that will travel together to the Sun-Earth Lagrange point L2. Then, the three modules will separate. One spacecraft will perform remote and upstream in situ observations of the target from afar, to protect it from the dust environment of the selected comet, and act as the primary communications hub with Earth. Two small probes carrying complementary instrument payloads will navigate to the chosen target thanks to its own propulsion system, providing key information about comet’s nucleus, gas, and plasma environment. The multi-point measurement will help to improve the 3D information required to better understand the interaction between a pristine comet and the solar wind environment.

Figure 1. Artist view of the Comet Interceptor spacecraft.


The payload consists in 10 instruments in total separated on three different spacecraft, as summarized in Table 1. The instrument total mass is 53 kg with a power consumption of 127 W. The main spacecraft will carry the Dust Field and Plasma (DFP) suite of instruments containing the COMPLIMENT instrument, the Belgian contribution to the Comet Interceptor mission. It consists of

  • A merged sensor, which is a spherical Langmuir probe that hold the FGM-A outboard magnetometer inside, mounted on the deployable boom.
  • A companion sensor, a spherical Langmuir probe mounted on the fixed COMPLIMENT boom.
Table 1. Spacecraft instrumentation and description.
  Spacecraft     Instruments   Description
A CoCa Visible/NIR imager
MIRMIS NIR/Thermal IR spectral imager
DFP Dust Field and Plasma containing the COMPLIMENT instrument (similar on S/C A and B2)
MANIaC Mass spectrometer
EnVisS All-sky multispectral visible imager
OPIC Visible/NIR imager
B1 HI Lyman-alpha hydrogen imager
PS Plasma suite
WAC Wide Angle Camera

B.RCLab contribution

COMPLIMENT harnesses include RC circuits made of an overbraid and a resistor, which are located between the boom and the surface of the guard. Therefore, they will be subject to substantial temperature variations while in space. Consequently, B.RCLab performed preliminary thermal tests of the resistors to verify that the selected candidates can sustain such expected temperature fluctuations. Figure 2 summarizes thermal tests performed on the resistors.

CI ThermalTests
Figure 2. Thermal test of the resistors.

Current status

The COMPLIMENT instrument is still under development. Studies concerning the Preliminary Design Review (PDR) will lead to a selection and validation by ESA at the end of June 2022. Depending on this selection, the B.RCLab will be involved for further studies (thermal tests, space qualification).


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