I don't have warframe installed right now wat doooo
Actually you should reinstall it right now, DE created a new grineer enemy and in their infinite sleekness gave it the boss drop table. Then they gave a low-level mobile defense mission which takes place on Earth, where you will fight dozens of them. The result?
And the mission is repeatable. Anyone who's playing this and needs neurodes or cells, go do the event before this gets fixed because I seriously doubt this is working as intended.