0 If a rocket blasts off, it leaves the ground to go into space.
1 the moment when a spacecraft leaves the ground:
Five seconds to blast-off!
2 (esp. of a spacecraft) to take off:
Children choose the flight plan - blast-off, orbit or re-entry.
The noises always begin with a rocket blast-off noise as someone says 3... 2... 1...
In fact, one must now admit that in the decade which has followed there has been no such blast-off.
