This achievement is missable if you do not complete all loyalty missions for each crew mate.
For this achievement you will need to have completed each of the 7 crew members Loyalty missions, (not their side quest missions (Based around activities) before you complete the final story mission 'Grand Finale'. You will be given a warning prompt that once you start, you will not be able to return to the simulation until the finale is over so you wouldn't be able to do these loyalty quests.
You can do these at any time (Once you've saved the crew member) and they can be done in co-op.
The missions are called as follows:
Kinzie - The girl who beat Cyrus
Matt - Nytefall
Pierce - Pump up the volume
Shaundi - Girls night out
Asha - Training Day
Ben - King of the dance
Gat - SR3 Wrap Up