Quote Originally Posted by Brother Oni View Post
Wiki says Grineer Settlement, so Mars is where you need to go.

The issue is that they only start spawning at level 15+ and the majority of Mars is ~13, so you need at least one round of an endless to get the level high enough for them to start spawning. I'd suggest either excavation or survival since in my experience, you encounter more varied spawns if you move around a lot.
It's my synthesis target, so I should get a message from Simaris if one is there at the start of the mission. But if they don't start spawning until I've done a couple rounds, will he still tell me when I load in?

Also, I have to do it solo, with a hobbled key, and without using any abilities to unlock a Riven, so I was really hoping to find something that would be less painful than an endless mission...