Here is the full list of all 25 Space Ribbon achievements.
Unlock the Comet!
Finish first place in any race!
Fall off the track and fail!
Finish First in all Cups!
Unlock the Space Racer!
Unlock the Panther!
Unlock the Space Panther!
Unlock the Firebird!
Win 10 Races!
Win 40 Races!
Win 100 Races!
Complete the Panda Cup
Complete Tiger Cup
Unlock all the Morris upgrades
Unlock all the Comet upgrades
Unlock all the Panther upgrades
Unlock all the Firebird upgrades
Slipstream another vehicle
Drift your car!!
Complete the Cosmic Cup
Complete the Closed Cup
Complete the Open Cup
Win a Drag Race