BepiColombo Radiator Breadboard Performance Test 2008-01-2063
The BepiColombo satellite is Europe's polar-orbiting Mercury satellite. It provides a 3 axis stabilized, nadir pointing platform for exploration of Mercury by a set of instruments. The Mission is lead by Astrium Friedrichshafen, with Thales Alenia Space Turin responsible for the Mercury Polar Orbiter thermal design.
The specific challenge of this mission is the thermal environment. The solar intensity varies between 14500W/m2 and 6700W/m2 along the seasons. In addition, due to the slow rotation period of Mercury, the planet temperatures exceed 700K at the subsolar point, which lead to about 4500W/m2 IR load at orbit height (Figure 3).
The mission concept allows only one side of the satellite to be always in shadow, while all other sides are illuminated by sun during different times of orbit and season. This radiator side is looking “sideways” (perpendicular to the flight direction). Therefore specific designs are implemented to reject the radiation from the planet.
In the frame of a technology demonstrator study (TDA), the radiator design was established and a breadboard tested in 2004 by Astrium Friedrichshafen. A parallel study was conducted by Thales Alenia (covered by another paper). Further design improvements were made thereafter and the performance of the updated breadboard tested in October 2007.
This paper reports on the design concept, test setup to simulate the influence of the hot Mercury surface and initial testing in 2004. The design updates for the current radiator are outlined and finally the correlation results between predicted and measured temperatures are discussed.