SpaceX launched a Falcon 9 rocket with 51 more Starlink internet satellites from California on Friday after a delay of several days to wait for liftoff of a higher-priority crew mission from Florida.
NASA, SpaceX’s customer for the astronaut mission, wanted time to review data from previous Falcon 9 flights before giving the green light for the launch of a four-man crew to the International Space Station. The requirement bumped the Starlink launch from California until after the Crew-6 mission took off from Kennedy Space Center early Thursday.
With the astronauts on their way to the space station, SpaceX was clear to launch the Falcon 9 from Vandenberg Space Force Base in California at 10:38:50 a.m. PST (1:38:50 p.m. EST; 1838:50 GMT) Friday.
The Falcon 9 rocket ignited nine Merlin main engines and climbed away from Space Launch Complex 4-East, SpaceX’s launch site on the West Coast. The kerosene-fueled main engines produced 1.7 million pounds of thrust as the rocket arced south-southeast from Vandenberg over the Pacific Ocean.
Two-and-a-half minutes into the mission, the booster stage of the Falcon 9 shut down and separated from the rocket’s upper stage, which ignited a single engine to continue the flight into orbit. The reusable booster, flying for the 12th time, extended grid fins and fired a subset of its engines for two braking maneuvers before settling onto a drone ship in the Pacific west of Baja California.
The vessel will return the rocket to Southern California for refurbishment and reuse.
The upper stage placed the 51 Starlink satellites into a low-altitude transfer orbit, then released the payloads about 15 minutes after liftoff. The mission, known as Starlink 2-7, marked the 15th SpaceX launch of the year, and the 76th SpaceX launch primarily dedicated to deploying satellites for the Starlink internet network.
The Starlink 2-7 mission Friday aimed to deploy the 51 Starlink satellites into an orbit between 138 miles and 207 miles (222-by-333 kilometers) above Earth. The satellites will extend their solar arrays and switch on krypton-fueled ion thrusters to raise their orbits to an altitude of 354 miles (570 kilometers), where they will become part of Group 2 of the Starlink constellation.
SpaceX’s first-generation Starlink fleet is spread out into five groups, or orbital shells, between 335 miles and 354 miles in altitude. The first-generation Starlink shells are inclined at different angles to the equator, with some satellites orbiting between 53 degrees north and south latitude, and others in orbits flying from pole-to-pole.
SpaceX began launching satellites into its second-generation Starlink constellation, called Gen2, in December, and debuted a larger, more capable version of the Starlink satellite design on a launch Feb. 27. But the Starlink 2-7 mission from Vandenberg continued filling out the first-generation Starlink fleet with the older satellite design, known as Starlink V1.5.
The 51 Starlink internet satellites on-board the rocket Friday brought the total number of Starlink spacecraft launched to 4,053.
The Federal Communications Commission granted SpaceX approval Dec. 1 to launch up to 7,500 of its planned 29,988-spacecraft Starlink Gen2 constellation. The regulatory agency deferred a decision on the remaining satellites SpaceX proposed for Gen2.
The FCC previously authorized SpaceX to launch and operate roughly 4,400 first-generation Ka-band and Ku-band Starlink spacecraft that SpaceX has been launching since 2019.
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