[ComputerGuru]

> The coolant used for the system? About a gallon (3.7 liters) of deionized water. While plenty of chemical coolants exist, the range of temperatures the spacecraft will be exposed to varies between 50 F (10 C) and 257 F (125 C). Very few liquids can handle those ranges like water. To keep the water from boiling at the higher end of the temperatures, it will be pressurized so the boiling point is over 257 F (125 C).

[close04]

I just imagined that for an object sent to the Sun they'd want to... overdo it a little. Go for something synthetic that would behave even better or would save 1/2 Kg.

I'm just the inquisitive type. Explaining that something is used always makes me wonder "why not something else" :).

[tesseract]

Water has a higher specific heat than most substances, and probably the highest of anything that's a liquid across the operating temperature range for the electronics.