Typical whole orbit data for the panel and chassis temperatures are as follows:
Black panel Max 25 Min -15
Silver panel Max 29 Min -12
Black chassis Max 25 Min -12
Silver chassis Max 25 Min -12
The black panel should absorb and radiate heat faster than the silver panel, if these changes are only due to radiation. The temperature of the black panel should then rise and fall more quickly than that of the silver panel.
Similarly, the silver panel should reflect heat more effectively than the black panel. Therefore the temperature of the silver panel should rise and fall more slowly than that of the black panel, assuming temperature changes are only due to radiation
The results show that the black panel falls to a lower temperature than the silver panel, which is in line with heat loss due to radiation only. However, the silver panel rises to a higher temperature than the black panel, which cannot be explained, if changes are only due to heat absorption. Surely, the black panel would be expected to rise to the higher temperature? Both panels are attached to the chassis. If the black panel is losing heat to the chassis by conduction faster than the silver panel, this could explain why the silver panel rises to the higher temperature. However, this argument does not appear to hold up, since the panels appear to be offset from the chassis and each is only attached by two small screws. Loss of heat to the chassis by conduction would be slow. The range of temperature changes suffered by the black and the silver panels differs by only one degree, 40 for black and 41 for silver.
If anybody is able to provide me with a convincing explanation for the recorded temperature changes, I would appreciate it as I wish to explain the results to a class of children.
Ted, G3YWA