This is a Perty simple one Its woohoo achievement.
All u need is Two sims That can woohoo together and a rocket
1: Build the rocket and the lovebar for the two sims (U can also Work with More then 1 sim to build the rocket)
2: Click on sim or rocket and select "Woohoo in rocket" Or "Woohoo in rocket with"
3:Then watch Them fly off and Land back down again
Then u get the achievement!