As early as Tuesday morning, the Falcon Heavy will take flight for the first time since June 2019, ending a long period of inactivity for the world’s most powerful, operational rocket. Under the power of 27 Merlin engines in its first stage, the rocket will carry two space technology payloads into orbit for US Space Force.

Ahead of this much-awaited USSF-44 launch, it is natural to ask why it has been more than 40 months since the rocket last flew. And perhaps more importantly, does this suggest that the Falcon Heavy—developed internally at SpaceX, at the company’s own expense, for half a billion dollars—was a mistake?

But first, some details about the launch, which is set for 9:41 am ET (13:41) on Tuesday from Kennedy Space Center, in Florida.