An even Darker SOMA [ending spoilers]

[Cranky Old Man]

That's my point. It doesn't think by itself, because it's not an AI,

Catherine says that WAU is an AI. How could it not be an AI?

and can only act within the boundaries those protocols (if it hadn't become self-aware that is).

Catherine says that an AI doesn't "want" in the way that humans want. Catherine claims that you can't make enemies with an AI, because it's not self-aware. However, that is proven wrong when/if your arm is bitten off.

The protocols were most likely programmed by someone, perhaps Ross.

It was probably written either by Carthage Industries, or that other asian company. Ross developed the AI's neuro culture, but could only study it and guess at its behavior. I don't even think that Carthage Industries knew exactly how it worked, based on how the classied document we found in Sarang's cabin was phrased. When WAU then began to mutate, Ross was baffled and could only philosophize about what that meant. It was simplifying routines, and it did so on its own, and Ross could see its codes, but these went way over his genius head. The only way that Ross could think to stop it, would be to give it restructured gel. There was no way to simply reprogram it to behave, anymore than you can reprogram a human brain with lines of code.

I do, however, base a lot of my knowledge on Catherine's description of it as a cancer, it just grows uncontrollably.

Well, first of all, Catherine doesn't know about site Alpha, and the WAU central node there. That's a classified site who only entrusted members of Carthage Industries knows about (for some strange reason).
Secondly, that's the description of an AI that isn't self-aware, because up until this point, the attitude is that AI's can't even BE self-aware. ...but as I said before: Getting you to fire the ARK into space, could well be within its old protocols. It's just yet another way to preserve humanity. The problem is that it doesn't exactly know what "humanity" means. It clearly thinks that the brainscan robots are human, and that the living corpses are human, and probably that the monsters that we encounter are human too. ...so despite of me reasoning that WAU puppeteered humans in an ARK is NOT in fact humanity, WAU may be of the opposite opinion. Maybe it would be able to take over alien worlds with dragons and STILL consider it to be "spreading humanity".
Also, like a loose note that is found early in Tau says: The structure gel, that we're seeing growing throughout Pathos II, is NOT WAU. That's basically the BLOOD of WAU - its army of nano machines that build things, as directed by WAU. WAU itself started out as a large suspended metal ball surrounded by three needle like things, before it mutated, via its own gel, to the heart that we see in the heart chamber. That's the WAU.

About WAU on the ARK-satellite(forgot to quote). I don't know if the WAU-goo functions on its own if it's severed from the rest (and in space where it's quite cold, full of radiation, and a vaccum). I suppose it would need some kind of power source like the robot as its batteries, biological bodies have organs and electrical equipment has electricity. Then again the ARK is powered by solar power, so maybe?

Nano machines are shown as being able to make anything work (in the lab at Omicron(?) ) and since it has been shown to survive the extreme pressure of the abyss, and gastric aicd (hydrochloric acid), I'm sure that it will be able to shield itself against space just as much as a satellite can. Yes, it requires power, but it can hook up to the solar array. ...but it's not just the goo. The main corruption will occur from WAUs ability to corrupt programming. It can write its own programs just as it has rewritten its own.