Very curious to see how they manage it.
Either it will require systems that can operate at those temperatures, or active cooling.
It's barely possible there's a way to accomplish the former, but I have no idea how you'd do it for so many instruments. I have no idea how you'd accomplish the latter. What refrigeration cycle would work at those temperatures?
How would you power it? RTGs rely on thermal flow, too. Solar panels? Don't think so.
A quick search of Google didn't give me any answers, but I did find this.