In a few hours, a spacecraft should blast-off from Florida on the hunt for signs of alien life
Its destination is Europa, a deeply-mysterious moon orbiting the distant planet Jupiter 
Trapped under its icy surface could be a vast ocean with double the amount of water on Earth 
The Europa Clipper spacecraft will chase a European mission that left last year, but using a cosmic piggyback, it will overtake and arrive first 
With help of these “gravity assists,” Europa Clipper will achieve the velocity needed to reach Jupiter in April 2030 
