▶▶ 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.
There is no point... in backing up.
‫لا فائدة... من النسخ الاحتياطي.
Wozu noch … ein Backup machen …
Una copia de seguridad
no serviría de nada.
Una copia de seguridad
no serviría de nada.
Les sauvegardes ne servent plus à rien,
de toute façon.
Non avrebbe alcun senso...
Não adianta mais... fazer backup.
В резервном копировании… смысла нет.