Speaker
Description
Comet Interceptor is an ESA-led mission, in collaboration with JAXA, designed to perform the first flyby of a dynamically new comet—a pristine object making its first passage through the inner Solar System. Rather than targeting a known body, the spacecraft, comprising a main module (A) and two probes (B1, B2), will be placed in a halo orbit around the Sun–Earth L2 point and remain there for potentially several years, until a suitable target is discovered and a transfer trajectory designed.
This mission profile presents thermal-control challenges with few precedents in previous scientific missions. During the extended waiting phase, the thermal control system (TCS) must maintain all units within survival limits in a stable, cold environment, relying primarily on passive insulation supplemented by heater lines designed for minimal power consumption while most of the spacecraft remains powered down.
The transfer phase can require solar illumination from any direction within the XZ plane to maintain communication with ground, potentially exposing most of the payload, propulsion system and optical instruments directly to the Sun. A lunar gravity-assist manoeuvre may further introduce a short-duration cold excursion through lunar eclipse, requiring the TCS to accommodate a rapid transient outside nominal environmental conditions.
During the comet flyby, trajectory correction manoeuvres and instrument pointing may result in direct solar illumination of the two main platform radiators. The TCS must therefore accommodate a wide range of external heat loads while remaining within stringent mass and power budgets.
This presentation describes the thermal-control approach adopted for Comet Interceptor and the principal challenges encountered during its design and analysis. Particular attention is given to worst-case definition under uncertain mission conditions, variable spacecraft interface temperatures, passive thermal-control design, heater-power limitations and thermal verification. Key design trades and the resulting approach to achieving robust thermal performance within mass and power constraints are presented.