Live coverage of the countdown and launch of a SpaceX Falcon 9 rocket from Launch Complex 39A at NASA’s Kennedy Space Center in Florida. The Starlink 4-21 mission launched SpaceX’s next batch of 53 Starlink broadband satellites. Follow us on Twitter.

SpaceX plans to launch 53 more Starlink internet satellites Thursday from Cape Canaveral. There are two launch opportunities available at 9:11 a.m. EDT (1311 GMT) and 10:30 a.m. EDT (1430 GMT). The Falcon 9 rocket’s reusable first stage will aim for landing on a drone ship in the Atlantic Ocean to complete its 13th flight to space.

The Falcon 9 will head northeast from Cape Canaveral Space Force Station to deliver the flat-packed broadband relay stations to an orbit ranging between 144 miles and 209 miles in altitude (232-by-337 kilometers). Deployment of the 53 flat-packed satellites from the Falcon 9’s upper stage occurred about 15 minutes after liftoff.

The launch is the first of five Falcon 9 missions SpaceX has scheduled for July. Three more Starlink deployment flights and a Dragon cargo flight to the International Space Station are planned later this month.

With Friday’s mission, SpaceX will have launched 2,759 Starlink internet satellites, including prototypes and test units no longer in service. The launch Friday will mark the 49th SpaceX mission primarily dedicated to hauling Starlink internet satellites into orbit.

Stationed inside a firing room at a launch control center just south of Cape Canaveral Space Force Station,, SpaceX’s launch team will begin loading super-chilled, densified kerosene and liquid oxygen propellants into the 229-foot-tall (70-meter) Falcon 9 vehicle at T-minus 35 minutes.

Helium pressurant will also flow into the rocket in the last half-hour of the countdown. In the final seven minutes before liftoff, the Falcon 9’s Merlin main engines will be thermally conditioned for flight through a procedure known as “chilldown.” The Falcon 9’s guidance and range safety systems will also be configured for launch.

After liftoff, the Falcon 9 rocket will vector its 1.7 million pounds of thrust — produced by nine Merlin engines — to steer northeast over the Atlantic Ocean.

The rocket will exceed the speed of sound in about one minute, then shut down its nine main engines two-and-a-half minutes after liftoff. The booster stage will release from from the Falcon 9’s upper stage, then fire pulses from cold gas control thrusters and extend titanium grid fins to help steer the vehicle back into the atmosphere.

Two braking burns will slow the rocket for landing on the drone ship “Just Read the Instructions” around 400 miles (650 kilometers) downrange approximately eight-and-a-half minutes after liftoff.

Credit: Spaceflight Now

The booster stage flying Thursday — tail number B1058 — will tie SpaceX’s record for the most-flown Falcon 9 first stage. It debuted May 30, 2020, with the launch of NASA astronauts Doug Hurley and Bob Behnken on SpaceX’s first crew flight to the International Space Station. It launched again in July 2020 with South Korea’s Anasis 2 military communications satellite, and has also boosted SpaceX’s CRS-21 cargo mission toward the space station.

The rocket stage also launched SpaceX’s Transporter 1 and Transporter 3 small satellite rideshare missions, and was used on seven previous Starlink missions. Most recently, the booster launched May 6 on the Starlink 4-17 mission.

SpaceX has qualified Falcon 9 boosters for at least 15 missions, up from the previous design life of 10 flights for each Falcon 9 first stage.

Landing of the first stage on Friday’s mission will occur moments after the Falcon 9’s second stage engine cuts off to deliver the Starlink satellites into orbit. Separation of the 53 spacecraft, built by SpaceX in Redmond, Washington, is expected at T+plus 15 minutes, 30 seconds.

Retention rods will release from the Starlink payload stack, allowing the flat-packed satellites to fly free from the Falcon 9’s upper stage in orbit. The 53 spacecraft will unfurl solar arrays and run through automated activation steps, then use krypton-fueled ion engines to maneuver into their operational orbit.

The Falcon 9’s guidance computer aims to deploy the satellites into an elliptical orbit at an orbital inclination of 53.2 degrees to the equator. The satellites will use on-board propulsion to do the rest of the work to reach a circular orbit 335 miles (540 kilometers) above Earth.

The Starlink satellites will fly in one of five orbital “shells” used in SpaceX’s global internet network. After reaching their operational orbit, the satellites will enter commercial service and begin beaming broadband signals to consumers, who can purchase Starlink service and connect to the network with a SpaceX-supplied ground terminal.

ROCKET: Falcon 9 (B1058.13)

PAYLOAD: 53 Starlink satellites (Starlink 4-21)

LAUNCH SITE: SLC-40, Cape Canaveral Space Force Station, Florida

LAUNCH DATE: July 7, 2022

LAUNCH TIME: 9:11 or 10:30 a.m. EDT (1311 or 1430 GMT)

WEATHER FORECAST: 80% chance of acceptable weather; Low risk of upper level winds; Low-moderate risk of unfavorable conditions for booster recovery

BOOSTER RECOVERY: “Just Read the Instructions” drone ship east of Charleston, South Carolina

LAUNCH AZIMUTH: Northeast

TARGET ORBIT: 144 miles by 209 miles (232 kilometers by 337 kilometers), 53.2 degrees inclination

LAUNCH TIMELINE:

T+00:00: Liftoff T+01:12: Maximum aerodynamic pressure (Max-Q) T+02:27: First stage main engine cutoff (MECO) T+02:30: Stage separation T+02:37: Second stage engine ignition T+02:42: Fairing jettison T+06:48: First stage entry burn ignition (three engines) T+07:08: First stage entry burn cutoff T+08:23: First stage landing burn ignition (one engine) T+08:31: Second stage engine cutoff (SECO 1) T+08:35: First stage landing T+15:30: Starlink satellite separation

MISSION STATS:

162nd launch of a Falcon 9 rocket since 2010 170th launch of Falcon rocket family since 2006 13th launch of Falcon 9 booster B1058 141st Falcon 9 launch from Florida’s Space Coast 91st Falcon 9 launch from pad 40 146th launch overall from pad 40 104th flight of a reused Falcon 9 booster 48th dedicated Falcon 9 launch with Starlink satellites 28th Falcon 9 launch of 2022 28th launch by SpaceX in 2022 29th orbital launch based out of Cape Canaveral in 202

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