4:20pm ET Update: Another mission success for SpaceX. Not only did the rocket's second stage successfully deploy the Es’hail-2 satellite into a geostationary transfer orbit on Thursday, the rocket's first stage also safely landed on a drone ship in the Atlantic Ocean.

With Thursday's launch, SpaceX has now flown 18 mission this year, tying its record set in 2017. The company could fly as many as four more rockets this year.

Original post: In 2017, SpaceX finally answered critics of the company who said it had not delivered on the promise of a high flight rate for its low-cost launch program.

Prior to last year, the critics were not wrong—SpaceX had never successfully launched more than eight rockets in any given year. Finally, in 2017, it attempted 18 launches, and all made it safely into space. The SpaceX steamroller had arrived.

This year the company has had a lot on its plate. It flew the large Falcon Heavy rocket for the first time in February. It introduced a brand-new, potentially highly reusable variant of the Falcon 9 rocket in May . And all throughout the year, the company's engineers have been scrambling to finalize development of the Dragon spacecraft to meet NASA's needs to get its astronauts to the International Space Station.

Even so, the company has maintained a steady launch cadence, and on Thursday the company will attempt its 18th mission of this year from Launch Complex-39A at Kennedy Space Center in Florida. The Thursday launch window for the Es’hail-2 satellite mission opens at 3:46pm ET (20:46 UTC) and lasts until 5:29pm ET (22:29 UTC). Weather conditions are 60 percent favorable, and a back-up launch window exists for Friday afternoon.

The Es’hail-2 satellite will provide telecommunications services for the Middle East and North Africa regions as well as providing the first amateur radio geostationary communication capability. The three-ton satellite will be delivered to a geostationary transfer orbit.

The first stage of this Falcon 9 rocket, a Block 5 variant of the booster, first flew on July 22 to launch the Telstar 19V mission. The company will attempt to land the first stage on the Of Course I Still Love You drone ship that will be located offshore in the Atlantic Ocean. This landing will come about eight minutes after liftoff, and the satellite is scheduled to be deployed into its transfer orbit a little more than 32 minutes into the flight.

After this mission, SpaceX has a busy year-end planned, with as many as four flights remaining before the end of December. Its next flight could come as early as Monday, with the launch of dozens of small satellites on the SSO-A mission, including two CubeSats for Kazakhstan.

The webcast below should begin about 15 minutes before the launch window opens on Thursday.