SpaceX has picked out which one of its landed Falcon 9 rockets it wants to re-fly for the first time. The plan is to reuse the vehicle that landed in April — the first Falcon 9 that SpaceX successfully landed on a drone ship in the ocean, and the second rocket the company has landed ever.

That rocket will likely fly sometime this fall

That Falcon 9 will likely fly sometime this fall, either in September or October, according to CEO Elon Musk. Though in April, Musk had offered a much more optimistic turnaround time, claiming that the first Falcon 9 rocket to fly again could happen as early as May or June. SpaceX still hasn’t announced what will fly on this launch, but Hans Koenigsmann, vice president of flight reliability for SpaceX, said the the company is finalizing talks with a potential customer.

It makes sense that SpaceX will launch this particular Falcon 9 first. It's one of the earlier ones the company landed, so SpaceX has had more time to make it flight ready. Plus, Musk noted the company's first ever landed rocket wouldn't ever fly again. "I think we’ll probably keep this one on the ground," Musk said December after that landing, "just [because] it’s kind of unique, it’s the first one we’ve brought back."

Spacex lands rocket at sea, makes history