Mimesis - Mimicked a Mimic

Tee One Up - Killing an enemy which is lifted

Escape Velocity - Blast yourself up as an object for at least 20 meters in normal gravity

Dear Future Self - You found and listened to all the messages you left for yourself
The First one is story-related and is found in your office. You will have to reestablish the looking glass connection to watch the whole thing.
The Second one is a collection of audio logs you left on your personal computer in your room in the Crew Quarters.
The Third one is story related and is found in Alex's office in the Arboretum. Alex will call you and ask for you to come and watch the looking glass video you left yourself.
The Fourth one is located in Alex's safe room, near the end of the game. You'll actually pick up two audio logs, one from Alex and one from yourself. You have to manually bring up your inventory and activate it in your Audio Log section for the achievement to unlock.