[quote=@Dervish]
<Snipped quote by Fallenreaper>

<Snipped quote by Mortarion>

From what I understand, the ships that leave for Andromeda left between ME2 and 3 and everyone on board was put into stasis for the journey, kinda why Javik still looks like what I assume is a Prothean porn star in his culture after 50,000 years. 
[/quote]

If memory doesn't fails me, the Nexus and the Arks left 6 months before the events of Arrival/the beginning of the Reaper War. And yeah, they all went in stasis a la Javik like Dervs said