There is a caster/cloth transmog set in World of Warcraft that has some casters (I've seen a mage and warlock thus far) look like they're in a completely white space suit. It's unbelievably cool looking and I'd love to get the set for my mage and priest. The head piece looks like an astronaut helmet and everything else is totally white. I'm so sorry for sounding vague, but surely someone here who is into transmog knows what I'm talking about?
** NOTE **
I'm still trying to search for the armory link of an individual I've seen in this suit. I unfortunately don't remember their characters name. Will update this thread if I find it.
Best Answer
With the many different transmog options out there, the individual pieces that the players used could be one of many. However, assuming that this is a fairly common set and focusing on the "all white" and astronaut-like look leads to a couple of possibilities. According to the list of transmog sets on wowhead for caster classes (priest/warlock/mage):
[a] The set with the most astronaut-like helmet while being (mostly) white is the Whisperwind Regalia set.
[b] Relaxing the all-white standard (on the assumption that a player could use white items from other sets or non-sets), there are two other head pieces that could conceivably be construed for astronaut helmets: The Cowl (or Hood) of the Cleansing Flame and The Crown of Burning Waters. (Both links are to the full transmog set for those items.