when was this jet airline launched?
February 1999
JetBlue
 David Neeleman founded the company in February 1999, under the name "NewAir". 
first jetblue mint flight between jfk and lax UNANSWERABLE what is "jetblue mint? Mint is a premium airline product offered by JetBlue on some flights between the West Coast and the East Coast of the contiguous United States, and seasonally on some flights between the United States and Caribbean destinations.
wiki:13270774
JetBlue [SEP] 1998–2000 founding
JetBlue was incorporated in Delaware in August 1998. David Neeleman founded the company in February 1999, under the name "NewAir". JetBlue started by following Southwest's approach of offering low-cost travel, but sought to distinguish itself by its amenities, such as in-flight entertainment, TV at every seat, and Sirius XM satellite radio. In September 1999, the airline was awarded 75 initial take-off/landing slots at John F. Kennedy International Airport and received its USDOT CPCN authorization in February 2000. It commenced operations on February 11, 2000, with services to Buffalo and Fort Lauderdale. JetBlue's founders had set out to call the airline "Taxi" and therefore have a yellow livery to associate the airline with New York.