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 4-25 mission will launch SpaceX’s next batch of 53 Starlink broadband satellites. Follow us on Twitter.

SpaceX plans to send another cluster of 53 Starlink internet satellites in orbit Sunday aboard a Falcon 9 rocket, the company’s 33rd mission of the year and sixth launch of July. Liftoff from pad 39A at NASA’s Kennedy Space Center in Florida is set for 9:38 a.m. EDT (1338 GMT).

The Falcon 9 booster will land on SpaceX’s drone ship parked downrange in the Atlantic Ocean northeast of Cape Canaveral.

The rocket will head northeast from the Kennedy Space Center, aiming to deliver the flat-packed broadband relay stations to an orbit ranging between 144 miles and 210 miles in altitude (232-by-338 kilometers). Deployment of the 53 flat-packed satellites from the Falcon 9’s upper stage occurred about 15 minutes after liftoff.

With Sunday’s mission, designated Starlink 4-25, SpaceX will have launched 2,957 Starlink internet satellites, including prototypes and test units no longer in service. The launch Sunday will mark the 53rd SpaceX mission primarily dedicated to hauling Starlink internet satellites into orbit.

Stationed inside a firing room at a launch control center at Kennedy, 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 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 “A Shortfall of Gravitas” around 400 miles (650 kilometers) downrange approximately eight-and-a-half minutes after liftoff.

Credit: Spaceflight Now

The booster flying on the Starlink 4-25 mission, known as B1062, will launch on its eighth trip to space. It debuted with the launch of a U.S. military GPS navigation satellite in November 2020, and launched the all-private Inspiration4 and Axiom-1 crew missions in September 2021 and in April of this year.

Most recently, the booster flew June 8 with the Egyptian Nilesat 301 geostationary communications satellite.

Landing of the first stage on Sunday’s mission will occur moments after the Falcon 9’s second stage engine cut off to deliver the Starlink satellites into orbit. Separation of the 53 spacecraft, built by SpaceX in Redmond, Washington, from the Falcon 9 rocket is scheduled at T+plus 15 minutes, 24 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” at different inclinations for 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.

If the Starlink 4-25 missions lifts off as scheduled Sunday, SpaceX will have launched six Falcon 9 rockets in just 17 days this month, deploying 251 Starlink internet satellites on five flights while also dispatching a Dragon cargo capsule to the International Space Station.

ROCKET: Falcon 9 (B1062.8)

PAYLOAD: 53 Starlink satellites (Starlink 4-25)

LAUNCH SITE: LC-39A, Kennedy Space Center, Florida

LAUNCH DATE: July 24, 2022

LAUNCH TIME: 9:38:20 a.m. EDT (1338:20 GMT)

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

BOOSTER RECOVERY: “A Shortfall of Gravitas” drone ship east of Charleston, South Carolina

LAUNCH AZIMUTH: Northeast

TARGET ORBIT: 144 miles by 210 miles (232 kilometers by 338 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+08:25: First stage landing burn ignition (one engine) T+08:43: Second stage engine cutoff (SECO 1) T+08:46: First stage landing T+15:24: Starlink satellite separation

MISSION STATS:

167th launch of a Falcon 9 rocket since 2010 175th launch of Falcon rocket family since 2006 8th launch of Falcon 9 booster B1062 144th Falcon 9 launch from Florida’s Space Coast 52nd SpaceX launch from pad 39A 146th launch overall from pad 39A 109th flight of a reused Falcon 9 booster 53rd dedicated Falcon 9 launch with Starlink satellites 33rd Falcon 9 launch of 2022 33rd launch by SpaceX in 2022 32nd orbital launch attempt based out of Cape Canaveral in 2022

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