SpaceX has no plans to relax following their recent successful weekend doubleheader. Serial entrepreneur Elon Musk’s space venture company is already looking ahead, beginning with a final upgrade to their Falcon 9 rocket scheduled for later this year.

“We are flying Block 3s right now,” SpaceX president and COO Gwynne Shotwell said during a June 22 appearance on the online radio program The Space Show. “Block 4s start flying shortly, and then Block 5 at the end of this year. We definitely have gotten better [at] more smooth introducing of change. You don’t see the big impacts to production we’ve had before when we’ve changed vehicle designs.”

Block 5 is going to be the definitive version for the Falcon 9, Shotwell explained, and it is capable of being relaunched “a dozen or so times.” It would also not require refurbishing — the reusable rocket would simply undergo inspections prior to launch.

Shotwell said during her radio show appearance that SpaceX’s much larger Falcon Heavy’s first mission in 2018 will be carrying a payload for Arabsat. “We’ll be flying Arabsat to [geostationary transfer orbit] on the second Falcon Heavy flight, and then we’ll be flying STP-2, an Air Force mission,” she said. In total, the Falcon Heavy has three missions scheduled in the next 18 months, the first being a demonstration later in 2017.

SpaceX has much more planned for the months to come, including that commercial Moon roundtrip. “Three years ago or so we were producing six rockets a year,” Shotwell said. “This year we are going to produce more than 20.” When you consider that reusability is a key element of SpaceX’s design, you can imagine just how many missions those rockets will be capable of handling in the coming years.