Out of all 14 missions, there are a total of 70 medals to be earned, 5 per mission.
One Medal each (Mission Complete) will be awarded for completion of the mission alone, one each (Enduring Service Medal) for completing missions without dying, and one each (Efficiency Medal) for completing missions within a certain time limit. The other two medals are mostly connected to optional objectives.
You can earn medals across various playthroughs, so you don’t have to earn all medals in a single session.
Restarting a checkpoint will void the Enduring Service Medal even if you didn't die - I strongly recommend to go for the Story Mode difficulty to also make the time-based medals a breeze.
In certain missions, some medals will give you additional achievements as well.
Mission 1: Form the Vanguard*** Spoiler - click to reveal ***Mission Complete: Complete Mission 1
Efficiency Medal: Completed Mission 1 in 16 minutes or less
Enduring Service Medal: Complete Mission 1 without dying
Defense Breaker: Destroy all TIE fighters before taking out the Jammers
Loyal Recruit: Destroy Imperial Jammers before the Cruiser to call New Republic reinforcements
Mission 2: The Skies of Yavin*** Spoiler - click to reveal ***Mission Complete: Complete Mission 2
Efficiency Medal: Complete Mission 2 in 13 minutes or less
Enduring Service Medal: Complete Mission 2 without dying
Trusty Wingmate: Save Frisk from a deadly tail
Intelligence Operative: Discover the Victorum’s breach point on the first scan (Note: It's the breach point at the back of the Star Destroyer, below the bridge)
Mission 3: Through Enemy Lines*** Spoiler - click to reveal ***Mission Complete: Complete Mission 3
Efficiency Medal: Complete Mission 3 in 15 minutes or less
Enduring Service Medal: Complete Mission 3 without dying
Not Even Close: The Victorum escaped with at least 30% hull integrity
Raider Wrecker: Destroyed all Imperial Raiders during the Victorum’s escape
If you managed to keep the Victorum's hull integrity above 30% when it escapes, you will earn this achievement:
Mission 4: Secrets and Spies*** Spoiler - click to reveal ***Mission Complete: Complete Mission 4
Efficiency Medal: Complete Mission 4 in 13 minutes or less
Enduring Service Medal: Complete Mission 4 without dying
Collateral Damage: Destroyed New Republic GR-75s before any escape
Thin the Herd: Destroyed all remaining fighters before the Gladius' arrival
Mission 5: The Trail From Desevro*** Spoiler - click to reveal ***Mission Complete: Complete Mission 5
Efficiency Medal: Completed Mission 5 in 14 minutes or less
Enduring Service Medal: Complete Mission 5 without dying
Marksman: Prevented any missile from damaging the GR-75s
Ionizer: Disabled all GR-75 transports
If you managed to destroy all missles before they reach the GR-75s, you will earn this achievement:
Mission 6: Signal to Noise*** Spoiler - click to reveal ***Mission Complete: Complete Mission 6
Efficiency Medal: Completed Mission 6 in 11 minutes or less
Enduring Service Medal: Complete Mission 6 without dying
Corvetter Protector: Save the Corvette
Reinforcements Denied: Destroy the communication dishes
Mission 7: Into the Abyss*** Spoiler - click to reveal ***Mission Complete: Complete Mission 7
Efficiency Medal: Complete Mission 7 in 13 minutes or less
Enduring Service Medal: Complete Mission 7 without dying
Abyssal Protector: Shot down three missiles fired by the Overseer
Fully Escorted: Protected all GR-75s transports
If you managed to keep all GR-75s alive, you will earn this achievement:
Mission 8: Fractured Alliance*** Spoiler - click to reveal ***Mission Complete: Complete Mission 8
Efficiency Medal: Complete Mission 8 in 17 minutes or less
Enduring Service Medal: Complete Mission 8 without dying
Toothless: Destroyed all of the Nebulon-B Frigate's turrets first
Depot Defender: All three Control towers survived the attack
Mission 9: Chaos at Mon Cala*** Spoiler - click to reveal ***Mission Complete: Complete Mission 9
Efficiency Medal: Complete Mission 9 in 13 minutes or less
Enduring Service Medal: Complete Mission 9 without dying
No Mercy: Destroy the Medical Frigate
No Cargo: Destroy all Cargo Ships
Mission 10: Terisa's Vengeance*** Spoiler - click to reveal ***Mission Complete: Complete Mission 10
Efficiency Medal: Complete Mission 10 in 13 minutes or less
Enduring Service Medal: Complete Mission 10 without dying
Imperial March: Destroyed all of the Nadiri Dockyards' hangars
No Survivors: Destroyed all GR-75 evacuees
Mission 11: Nowhere to Stand*** Spoiler - click to reveal ***Mission Complete: Complete Mission 11
Efficiency Medal: Complete Mission 11 in 17 minutes or less
Enduring Service Medal: Complete Mission 11 without dying
Capital Destruction: Destroyed two capital ships in 15 seconds or less
Core Knowledge: Scanned all active cores
Mission 12: Rally the New Republic*** Spoiler - click to reveal ***Mission Complete: Complete Mission 12
Efficiency Medal: Complete Mission 12 in 16 minutes or less
Enduring Service Medal: Complete Mission 12 without dying
Comsat Savior: Do not allow any Comsats to be destroyed
Loud and Clear: Destroy the Jammer in less than a minute
Mission 13: Fire in the Heart*** Spoiler - click to reveal ***Mission Complete: Complete Mission 13
Efficiency Medal: Complete Mission 13 in 18 minutes or less
Enduring Service Medal: Complete Mission 13 without dying
Vengeance: Shot down the traitor while maintaining 50% hull integrity or higher
Thread the Needle: Reach the Starhawk's core in 40 seconds without taking damage
Servant of the Empire: Complete all Imperial missions
If you managed to reach the core in 40 seconds or less without taking any damage, you will earn this achievement:
Mission 14: Last Flight of the Starhawk*** Spoiler - click to reveal ***Mission Complete: Complete Mission 14
Efficiency Medal: Complete Mission 14 in 18 minutes or less
Enduring Service Medal: Complete Mission 14 without dying
Scorching Escape: Maintain maximum speed during the Galitan escape
Piece by Piece: Destroy 2 flagship subsystems