SpaceX test-fires repaired booster for weekend Starlink launch

SpaceX test-fires a Falcon 9 rocket Thursday at Cape Canaveral Space Force Station. Credit: Spaceflight Now

SpaceX rolled a Falcon 9 rocket to its launch pad at Cape Canaveral and test-fired its engines Thursday, prepping for liftoff Saturday night carrying another group of Starlink internet satellites into orbit. The Falcon 9 booster has been repaired after a rough recovery in December knocked it out of SpaceX’s rocket reuse rotation.

The 229-foot-tall (70-meter) rocket fired up its nine Merlin 1D engines at 9:10 a.m. EDT (1310 GMT) Thursday on Space Launch Complex 40 at Cape Canaveral Space Force Station. The engines ignited for about seven seconds, ramping up to 1.7 million pounds of thrust as hold-down restraints kept the Falcon 9 firmly on the ground.

SpaceX loaded a million pounds of densified kerosene and liquid oxygen propellants into the Falcon 9 during the final 35 minutes of the mock countdown Thursday. The Falcon 9 was already stacked with its payload of more than 50 Starlink internet satellites during the static fire test.

Engineers will analyze data from the static fire test before clearing teams to continue with the countdown Saturday night.

The mission, known as Starlink 4-23, will be the final launch from Florida’s Space Coast before NASA is set to launch the Artemis 1 mission from pad 39B at the Kennedy Space Center — a few miles north of pad 40 — as soon as Monday morning.

Liftoff of the Starlink 4-23 mission on the Falcon 9 rocket is set for 10:22 p.m. EDT Saturday (0222 GMT Sunday). Heading northeast from Cape Canaveral, the Falcon 9 rocket will target a deployment of the flat-packed Starlink internet satellites in low Earth orbit.

The Falcon 9 launch Saturday night will mark the 38th SpaceX mission of the year, and the 57th Falcon 9 flight primarily dedicated to deploying satellites for the Starlink internet network. SpaceX has launched more than 3,100 Starlink satellites to date, and Saturday’s flight is expected to add another 53 spacecraft to the fleet.

The first stage booster on the Starlink 4-23 mission is expected to make its second flight to space. Known as B1069, the booster was damaged during recovery on a drone ship Dec. 21 after launching its first mission, sending a Dragon cargo ship toward the International Space Station.

The rough recovery damaged the rocket’s engines and landing legs, causing the rocket to return aboard the drone ship to Port Canaveral on a tilt. The damage forced SpaceX and NASA to switch to a backup Falcon 9 booster for the launch of four astronauts to the space station in April. That launch was originally supposed to use B1069, which has been refurbished with new engines and other components.

After the launch Saturday, SpaceX plans to again recover the booster on a drone ship in the Atlantic Ocean.

Email the author.

Follow Stephen Clark on Twitter: @StephenClark1.