SpaceX has always had big ambitions of launching its Falcon 9 rockets as frequently as possible, and this year the company is hoping to reach its highest launch cadence yet. SpaceX president Gwynne Shotwell tells Reuters that the company “should be launching every two to three weeks” in 2017. If successful, it would be the fastest launch rate SpaceX has ever pulled off, launching the most rockets it has in one year.

It is a prediction that Shotwell has made for SpaceX before, though. In February of last year, she said that the company should being launching every two to three weeks in 2016, according to Space News. And for a few months, SpaceX got pretty close to meeting that expectation. But the company was forced to ground flights for the rest of the year after one of its Falcon 9 rockets exploded on a launchpad at Cape Canaveral, Florida in September. So rather than launching nearly two dozen rockets as expected, SpaceX only pulled off eight Falcon 9 missions in 2016.

That means the company has a big backlog of customers waiting to get their satellites into space this year. Financial records obtained by The Wall Street Journal revealed that SpaceX had hoped to fly 20 rockets last year and 27 rockets this year. Reuters notes that the company has a backlog of 70 missions worth $10 billion.

Engine cracks?

Meanwhile, SpaceX is working on updating the design of its rocket engines due to potential concerns with the Falcon 9’s safety. Recently, WSJ reported on a draft of an upcoming report from the Government Accountability Office, which supposedly reveals a pattern of cracking in the turbine blades of the turbopumps — the hardware that rapidly funnel propellant into the engines. Seeing as how SpaceX is slated to fly NASA astronauts on its vehicles as soon as 2018, the cracking allegedly has a few people at NASA worried about the safety of future crew members.

SpaceX responded to the report by saying that its engines are robust enough to withstand this type of cracking, but that the company plans to update the engines anyway as part of the final design iteration for the Falcon 9. Shotwell echoes this statement in her interview with Reuters, arguing that the update will be put in place before people fly on the Falcon 9 for the first time.

“For us, the concern was not the cracks, but do they grow over time? Would these cracks cause a flight failure?” Shotwell tells Reuters. “I think NASA is used to engines that aren’t quite as robust, so they just don’t want any cracks at all in the turbo machinery." The cracking was not implicated in SpaceX’s September 1st launchpad explosion.