More than five months after Southwest Airlines announced that it had signed a deal with Elon Musk’s SpaceX to offer ultra-fast Starlink internet across its massive fleet of more than 800 Boeing 737s, the first plane with the service has finally taken flight.

The milestone was reached on Monday when Southwest flight WN-3660 departed Dallas bound for Albuquerque. The first aircraft to be retrofitted with Starlink is an 8-year-old Boeing 737-800 (registration: N8543Z).