What does "blast off" mean?

Also, blast away. Take off or be launched, especially into space, as in They're scheduled to blast off on Tuesday. This usage originated with the development of powerful rockets, spacecraft, and astronauts, to all of which it was applied. [c. 1950]

Depart, clear out, as in This party's over; let's blast off now. [Slang; early 1950s]

Become excited or high, especially from using drugs, as in They give parties where people blast off. [Slang; c. 1960]