Chronology

2156
First probe to Arca, sent by Chinese space program, returns and reveals the planet as a human-friendly environment.

2236
The India/Pakistan war followed by nuclear winter kills 10% of humanity and awakens people to the fact that the species really could be completely destroyed, and that it's important for there to be a backup of humanity.

2240
The Arca Colony Treaty is signed, granting Jiji Corporation exclusive resource rights on Arca for 100 years in exchange for building and sending the 5 colony ships within the decade.

2248
With the ships on track for completion in 2250, Jiji begins recruiting employees.

2251
Five Emperors fleet leaves earth for Arca