▶▶ Pod 153 - Report:

The machine lifeforms not only infected the YoRHa soldier units on the ground, they also infected the <Bunker> with a viral attack, activating a self-destruct sequence.

With this, the 13th Orbital Satellite Base <Bunker> was destroyed. 

2B and 9S avoided infection from the virus and escaped the Bunker before it was destroyed. 
Proposal: Find the remaining surviving YoRHa Soldiers and start another descent-to-ground operation on Earth to fulfill the mission.
Okay, okay. Now, where is 2B?
‫حسنًا، حسنًا. أين 2.بي إذًا؟
Ja, ja, okay!
Claro, claro. ¿Dónde estará 2B?
Vale, vale. ¿Dónde estará 2B?
E ora, dove sarà 2B?
Tá, tá. Agora, onde está a 2B?
Ну ладно, ладно. Так, а где 2B?