Here is the full list of all 70 Heat Signature achievements.
Delete a Galaxy
Knock yourself out with a wrench you threw
Retire Sader Fiasco
Start a new galaxy
Talk to Fiasco after liberating every Stronghold
Rescue a friend's character
Complete a Hijack mission in a Warzone
Rescue one of your own characters
Make it to a station after your pod has been destroyed
Knock a Capture target through a window
Complete a Pacifist Clause
Teleport to an airlock with the Glitcher's Tick
Dock at a friendly station while on emergency fuel
Use a second Visitor before the first returns you
Complete an assassination mission without harming any other crew
Save someone with the Offworld Angel
Completely eliminate a faction from the galaxy
Complete an Assassinate mission without entering the ship
Complete a theft without being seen or harming anyone
Pass through a ship's vision undetected in the Sovereign Coldfire
Catch a Rescue target in your pod while they're suffocating in space
Complete a practice mission
Complete a Ghost Clause
Deliver an assassination target alive
Kill someone with a Shortblade within 1 second of killing someone with a Longblade
Complete a Mistake mission
Cause a sentry to shoot a guard by subverting it
Cause a guard with a subverted shield to shoot themselves
Be rescued from your captor by the Visitor
Board a ship without docking your pod
Acquire a keycard while Visiting
Reflect a bullet with an emergency shield
Retire as a Living Legend
Break a ship with the Foundry Brick
Cause a guard to shoot themselves by Swapping with them
Complete your personal mission
Crash a shield
Take someone out with a melee attack less than 0.5 seconds after Sidewinding
Complete an Audacious (or harder) mission
Complete a Hard (or harder) mission
Complete a Silence Clause
Liberate a station
Complete an Enigma Clause
Find a unique item
Complete a Bloodless Clause
Find an item that belonged to a Steam friend's character