Yes, I was being facile for the sake of a one-liner. Sorry about that. It will be in a certain kind of orbit around the L2 point, not right on top of the L2 p

Yes, I was being facile for the sake of a one-liner. Sorry about that. It will be in a certain kind of orbit around the L2 point, not right on top of the L2 point. This means it is not in Earth's shadow, as you note. It's in its own shadow. But if it were in a conventional orbit centered around Earth, it would have thermal issues, observational issues, etc., because pointing to keep the telescope away from the sun would be a big problem. My friend across the hall uses data from Planck, which is at L2, and I used to use data from SoHO (before its camera was shut down), which is at L1. We used to joke around about how each other's instrument was in a too cold/too hot place. Here's a nice illustration of Planck's orbit. (Planck was the sister satellite to Herschel.) http://planck.cf.ac.uk/mission/orbit http://planck.cf.ac.uk/mission/orbit