In December, SpaceX will again send cargo to the International Space Station — but this time, it will use a Falcon 9 rocket that has already flown to space and back. NASA officially confirmed the decision today during a meeting, noting that SpaceX’s upcoming resupply mission will fly on a Falcon 9 that already launched to the ISS in June. It marks the first time SpaceX will launch a used rocket for NASA, further validating the company’s reusable rocket technology.

“NASA participated in a broad range of SpaceX data assessments and inspections regarding use of a previously flown Falcon 9 first stage booster,” NASA said in a statement confirming the decision to The Verge. Ultimately, NASA will consider flying on used Falcon 9s on a case-by-case basis going forward, the space agency said.

NASA will consider flying on used Falcon 9s on a case-by-case basis going forward

Throughout 2017, SpaceX has been proving that its Falcon 9 rockets are just as capable of flying to space a second time around. The company launched three previously flown boosters this year, all of which sent satellites to orbit and then landed back on one of SpaceX’s drone ships post-launch. Their landings have opened up the possibility that these rockets could fly for a third time, and perhaps many times more than that.

But so far, only a few of SpaceX’s commercial customers have flown their hardware on used rockets. The first to do so was Luxembourg-based communications company SES, which flew its SES-10 satellite on a used Falcon 9 in March. Next to take the plunge was satellite operator Bulgaria Sat in June, followed by EchoStar and SES again, which sent up a hybrid satellite together on a used Falcon 9 in early October.

Other customers are coming around: satellite operator Iridium will launch its next two missions, Iridium-4 and Iridium-5, on used Falcon 9 rockets. And even Israeli satellite operator Spacecom has decided to fly its next satellite on top of a used vehicle — despite the company’s fiery history with SpaceX. Spacecom’s AMOS-6 satellite was destroyed when the Falcon 9 it was sitting on exploded during a fueling procedure last September. After the explosion, Spacecom sought compensation from SpaceX, either in the form of $50 million or a free flight on a Falcon 9. Now it looks like Spacecom is going with that latter option, in order to launch its next probe, AMOS-17, and isn’t afraid to use a previously flown booster either.

NASA has been open to flying with used SpaceX hardware. In June, SpaceX launched cargo to the space station using a Dragon capsule that had already flown to space and back. After that flight, a NASA official expressed interest in flying cargo on used Falcon 9s, noting that the space agency had discussed it. “We are looking at it,” Ven Feng, the manager of the ISS Transportation Integration Office, said during a press conference at NASA’s Kennedy Space Center in June. “We’re evaluating every aspect of it very carefully, and there is no schedule yet when we might go down that path.”

Now with NASA agreeing to fly on a previously flown Falcon 9, it’s possible others might hop on the bandwagon too — specifically the US military. Ever since getting certification to fly national security satellites, SpaceX has been slowly accruing more and more military launches. The company launched its first national security satellite in May for the National Reconnaissance Office and even lofted the Air Force’s super secret X-37B spaceplane in September.

And the US government has made it clear that flying on used Falcon 9 rockets is a definite option. General John W. “Jay” Raymond, head of US Air Force Space Command, told Bloomberg it would be “absolutely foolish” for the military not to fly on previously flown rockets in order to save on launch costs.