I don't know fully the details, but I worked on the Hubble servicing missions (I did the engineering on the boxes that transported up new cameras, gyros etc). I

I don't know fully the details, but I worked on the Hubble servicing missions (I did the engineering on the boxes that transported up new cameras, gyros etc). I did not work on the actual cameras, except to package them up. I suspect that the answer is that the cameras are designed to look into some of the deepest darkest regions of space, and are freakishly sensitive. So much so that keeping the cameras at frigid temperatures is a requirement in order to make sense of the signal they collect. Pointing it at the sun, I would assume, would be at best unusable, and at worst damaging. For some perspective - look up the NICMOS camera: http://en.wikipedia.org/wiki/Near_Infrared_Camera_and_Multi-Object_Spectrometer http://en.wikipedia.org/wiki/Near_Infrared_Camera_and_Multi-... There was a thermal short in the cooler that threatened it's life span, so they cooked up an external cooling system in order to keep the camera at some absurdly cold temperature like 60 Kelvin. (I could be wrong about the temp - but it's COLD).