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 Falcon 9 rocket will launch SpaceX’s 25th resupply mission to the International Space Station. Follow us on Twitter.

SpaceX’s 25th cargo resupply mission to the International Space Station is set for liftoff at 8:44 p.m. EDT Thursday (0044 GMT Friday) from NASA’s Kennedy Space Center in Florida. A Falcon 9 rocket will launch the Dragon capsule toward the station with nearly three tons of cargo.

Liftoff from pad 39A at Kennedy is set for precisely 8:44:22 p.m. EDT (0044:22 GMT), roughly the moment Earth’s rotation brings the launch site under the orbital plane of the space station.

There is a 70% chance of favorable weather for launch Thursday, according to the U.S. Space Force’s 45th Weather Squadron. The main weather concerns are with cumulus clouds that could create a risk for lightning, and flight through precipitation.

After liftoff, the Falcon 9 will head downrange northeast from Florida’s Space Coast, powered by nine Merlin engines generating 1.7 million pounds of thrust. The rocket will shut down its first stage booster about two-and-a-half minutes into the mission, allowing the booster to descend to landing on a drone ship about 186 miles (300 kilometers) downrange in the Atlantic Ocean about seven-and-a-half minutes after liftoff.

The booster, tail number B1067, is making its fifth flight on the CRS-25 mission. It previously launched the CRS-22 cargo mission last June, launched two NASA crew missions to the station, and hauled Turkey’s Turksat 5B communications satellite into space.

The Dragon spacecraft will deploy from the Falcon 9’s upper stage about 12 minutes after liftoff to begin the day-and-a-half journey to the International Space Station. The Dragon cargo capsule on the CRS-25 mission is launching on its third flight to the station.

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 215-foot-tall (65-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.

SpaceX’s Cargo Dragon spacecraft and Falcon 9 rocket roll out to pad 39A at the Kennedy Space Center in Florida ahead of launch of the company’s 25th cargo mission to the International Space Station. Credit: SpaceX

Assuming an on-time launch Thursday night, the Dragon cargo ship is scheduled to automatically dock at the space station’s Harmony module at 11:20 a.m. EDT (1520 GMT) Saturday.

Astronauts at the space station will open hatches and unpack supplies, experiments and other equipment stowed inside the Dragon capsule’s pressurized compartment. At the end of the mission, the reusable capsule will undock from the station and head for a parachute-assisted splashdown off the coast of Florida in mid-August with several tons of cargo.

The cargo ship is launching with around 5,800 pounds of supplies and payloads, including a NASA climate instrument to be mounted outside the space station.

The Earth Surface Mineral Dust Source Investigation, or EMIT, instrument was developed by NASA’s Jet Propulsion Laboratory. It will be attached to a mounting post outside the space station to measure the mineral content of the world’s desert regions, the source of global dust storms that can impact climate and weather worldwide.

Data collected by the instrument will help scientists learn more about how dust lifted into the atmosphere from deserts impact Earth’s ecosystems and human health.

“This is going to be a really busy mission for us,” said Dana Weigel, NASA’s deputy space station program manager. “It’s packed with a lot of science. The planned duration is about 33 days.”

The mission was originally scheduled to launch in early June, but SpaceX delayed the flight to resolve a vapor leak in the Dragon spacecraft’s propulsion system, and replace the capsule’s four main parachutes in a cautionary measure in case the chute material was degraded by the toxic propellant leak.

ROCKET: Falcon 9 (B1067.5)

PAYLOAD: Cargo Dragon (CRS-25)

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

LAUNCH DATE: July 14, 2022

LAUNCH TIME: 8:44:22 p.m. EDT (0044:22 GMT on July 15))

WEATHER FORECAST: 70% 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 Jacksonville, Florida

LAUNCH AZIMUTH: Northeast

TARGET ORBIT: 118 miles by 130 miles (190 kilometers by 210 kilometers), 51.6 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+02:38: Second stage engine ignition T+02:43: First stage boost back burn ignition (three engines) T+03:15: First stage boost back burn cutoff T+05:45: First stage entry burn ignition (three engines) T+05:59: First stage entry burn cutoff T+07:06: First stage landing burn ignition (one engine) T+07:33: First stage landing T+08:37: Second stage engine cutoff (SECO 1) T+11:49: Cargo Dragon separation

MISSION STATS:

164th launch of a Falcon 9 rocket since 2010 172nd launch of Falcon rocket family since 2006 5th launch of Falcon 9 booster B1067 143rd Falcon 9 launch from Florida’s Space Coast 51st SpaceX launch from pad 39A 145th launch overall from pad 39A 106th flight of a reused Falcon 9 booster 5th launch of upgraded Cargo Dragon 25th SpaceX cargo mission to the International Space Station 30th Falcon 9 launch of 2022 30th launch by SpaceX in 2022 30th orbital launch based out of Cape Canaveral in 2022

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Follow Stephen Clark on Twitter: @StephenClark1.