18-01-2022, 08:19 AM
Miles? Miles per hour, Fahrenheit?
At least the NASA site works in sensible units https://webb.nasa.gov/content/about/orbit.html
But even they quote the temperature as -233C. It is better to convert this to Kelvin, the temperature above absolute zero. The is 40K, which is pretty cold - liquid nitrogen boils at 77K, so the detector modules are 37K colder than liquid nitrogen.
So how do they maintain that sort of temperature? Well the business end points at deep space, which is at 3K - so provided you can shield the heat coming from the sun (and earth and moon) you get passive cooling for free.
Craig
At least the NASA site works in sensible units https://webb.nasa.gov/content/about/orbit.html
But even they quote the temperature as -233C. It is better to convert this to Kelvin, the temperature above absolute zero. The is 40K, which is pretty cold - liquid nitrogen boils at 77K, so the detector modules are 37K colder than liquid nitrogen.
So how do they maintain that sort of temperature? Well the business end points at deep space, which is at 3K - so provided you can shield the heat coming from the sun (and earth and moon) you get passive cooling for free.
Craig
