Here is the full list of all 20 Redshirt achievements.
Add Astra as a Spacebook friend
Get a 'like' on a Spacebook status or post
Host a Spacebook event for 3 or more people, where everyone turns up.
Maintain a single romantic relationship for 21 days. What commitment!
Get hired for a job at least 3 ranks above your Career Rank, without being properly qualified.
Have at least 6 different items from the S.H.O.P. in your inventory
Win the game by getting to the top of the career tree.
Get back together with a former romantic partner.
Get at least four likes on any Spacebook post you make.
Your romantic partner was killed on an away mission
Get into more than 8 different romantic relationships in a single playthrough
Win the game with away missions frequency setting at highest
Win the game with holodoctor intervention setting at highest
Achieve 4 aspirations in a single playthrough
Win the game through the 'bribery' route.
Win the game by making friends with the right people.
Win the game by maintaining a romantic relationship with the right person.
Win the game by buying your way off the station.
Win the game through two different routes.
Win the game through all 5 different routes.