*WARNING THIS IS MISSABLE, IF YOU DO NOT LET TINA LAUNCH THE ROCKET YOU WILL HAVE TO RE DO THE WHOLE DLC LIKE I DID*
During the mission 'Shooting the Moon' Tina will task you in collecting some parts for the rocket. You'll collect two electrical parts as well as two wings in which you'll place onto the rocket. She will then task you to go collect a power core from defeating 'Uranus Bot' and them you'll have to place that onto the rocket. Once you have done this you MUST talk to Tina to let her launch the rocket as the other option is to launch it yourself making this achievement void. After she launches the rocket, you should unlock the achievement! If playing in a multiplayer game or split screen, all players should unlock the achievement as well!
Video Guide Reference if needed:
*EDIT* Via Sons O Liberty - For anyone not getting the achievement or any of them in the new DLC. Go to settings on your XBOX ONE, remove account, add it again, let it download your information again, , load Borderlands 2, instant achievement pop, I've had to do this for almost every achievement.