The first step in privately held U.S. rocket company SpaceX's path to reusability was to land rockets. But after landing six of its last nine rockets, it's fair to conclude SpaceX is ready for the next step: actually reusing these rockets. And in the fourth quarter of this year, SpaceX will do exactly that.

Falcon 9 approaching landing zone. Image source: SpaceX.

SpaceX's first customer to fly a used Falcon 9

SES, a world-leading satellite operator with a fleet of more than 50 geostationary satellites, and SpaceX announced on Tuesday they have reached an agreement to use a "flight-proven" Falcon 9 orbital rocket booster to launch an SES-10 satellite into geostationary orbit.

The SES-10 satellite will fly atop a Falcon 9 rocket the company landed on a drone ship in April.

SES' agreement with SpaceX to fly a used rocket is an important milestone, bringing SpaceX a step closer to reusability.

"We believe reusable rockets will open up a new era of spaceflight, and make access to space more efficient in terms of cost and manifest management," said SES chief technology officer Martin Halliwell in a statement this week.

SES, which was the first commercial satellite company to launch with SpaceX in 2013, is confident and optimistic about the chance to reuse a landed Falcon 9.

"This new agreement reached with SpaceX once again illustrates the faith we have in their technical and operational expertise," Halliwell said.

SES likely didn't need much convincing. Earlier this year, SES reportedly "challenged" SpaceX to let it launch a satellite on a used Falcon 9, according to Spaceflight Now.

Ahead of a reflight later this year, SpaceX has been putting a first stage booster it landed in May under at least three intense test fires. The test fire blasts the rocket's engines at full thrust while holding the rocket down for the two-and-a-half minutes the stage would need to operate during an actual launch. Each test fire has been successful. Exposed to more extreme conditions than the company's other landed rockets, SpaceX's May-recovered Falcon 9 is being utilized as the company's flown benchmark vehicle. 

Driving the cost of spaceflight lower

The end goal in SpaceX's efforts to reuse its rockets is to significantly reduce the cost of spaceflight and to make the whole process of launching rockets easier.

SpaceX president and chief operating officer Gwynne Shotwell reiterated the company's goal in this week's statement about its agreement with SES: "Re-launching a rocket that has already delivered spacecraft to orbit is an important milestone on the path to complete and rapid reusability."

Indeed, lower costs thanks to reusability may already be a reality. SpaceX is giving SES a discount for using a flight-proven Falcon 9, according to The Verge. While the exact discount is unknown, Shotwell has previously estimated flying used Falcon 9's could reduce flight prices by 30%.

Used Falcon 9 rockets. Image source: SpaceX.

With a customer secured for SpaceX's first launch of a landed Falcon 9, the company's business model is likely about to become more profitable. Indeed, the company is already in negotiations to build a dedicated rocket refurbishing facility to support this new and critical leg of its business. While building out a fleet of reusable rockets is obviously good news for SpaceX, it may not be very exciting news for its competitors, which already charge higher prices for delivering cargo to space than SpaceX.

Now we will just have to wait and see whether or not SpaceX can actually pull this off.