January 31, 2023

SpaceX launches heaviest payload on Falcon 9 rocket

Watch a replay of our live coverage of the countdown and launch of a SpaceX Falcon 9 rocket on the Starlink 5-2 mission at 4:32 a.m. EST (0932 GMT) on Jan. 26 from Space Launch Complex 40 at Cape Canaveral Space Force Station, Florida. Follow us on Twitter.

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A Falcon 9 rocket thundered off a launch pad at Cape Canaveral before dawn Thursday with 56 Starlink internet satellites, setting a record for the heaviest cargo ever flown on a SpaceX rocket at more than 38,000 pounds.

The mission was the fifth launch by SpaceX so far this year, and the 69th launch with a primary purpose of placing Starlink internet satellites into orbit. With the 56 fresh spacecraft launched Thursday, SpaceX has deployed 3,773 Starlink satellites, with plans to add thousands more in the coming years.

Liftoff of the 229-foot-tall (70-meter) Falcon 9 rocket from pad 40 at Cape Canaveral Space Force Station occurred at 4:32:20 a.m. EST (0932:20 GMT) Thursday.

Light rain showers moved through the spaceport in the hour before liftoff, but conditions cleared sufficiently to permit the Falcon 9 to get off the ground on time.

The 56 Starlink internet satellites mounted on top of the Falcon 9 rocket headed into an orbital plane that is part of SpaceX’s second-generation Starlink net network, called Gen2. Thursday’s mission, known as Starlink 5-2, followed the first Starlink launch into the Gen2 network Dec. 28, which carried 54 satellites into a similar orbit.

SpaceX said the 56 spacecraft on Thursday’s launch totaled about more than 17.4 metric tons, or more than 38,000 pounds, breaking the record for the heaviest payload ever flown on a SpaceX rocket. The company’s engineers have experimented with engine throttle settings, fuel efficiencies, and another minor upgrades to stretch the Falcon 9’s lift capability.

SpaceX plans to eventually launch second-generation Starlink satellites on the company’s new Starship mega-rocket. Those satellites will be larger and more capable than SpaceX’s current fleet of Starlink spacecraft, and will be capable of transmitting signals directly to cell phones. But with the Starship rocket still undergoing preparations for its first orbital test flight, SpaceX officials signaled they will start launching the Gen2 satellites on Falcon 9 rockets.

Elon Musk, SpaceX’s founder and CEO, suggested in August that the company could develop a miniature version of the Gen2 satellites to fit on the Falcon 9 rocket.

The satellites on the first Gen2 launch last month appeared similar, or identical, to Starlink spacecraft SpaceX is already launching to complete its first-generation network, and not the larger Gen2 satellites destined to fly on the huge new Starship rocket, or even the mini Gen2 satellites Musk mentioned last year.

SpaceX’s Falcon 9 rocket climbs off of pad 40 at Cape Canaveral Space Force Station to begin the Starlink 5-2 mission. Credit: Stephen Clark / Spaceflight Now

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.

“Under our new license, we are now able to deploy satellites to new orbits that will add even more capacity to the network,” SpaceX wrote on its website before the first Gen2 launch Dec. 28. “Ultimately, this enables us to add more customers and provide faster service – particularly in areas that are currently over-subscribed.”

The FCC previously authorized SpaceX to launch and operate up to 12,000 Starlink satellites, including roughly 4,400 first-generation Ka-band and Ku-band Starlink spacecraft that SpaceX has been launching since 2019. SpaceX also received regulatory approval to launch more than 7,500 Starlink satellites operating in a different V-band frequency.

SpaceX told the FCC earlier this year it planned to consolidate the V-band Starlink fleet into the larger Gen2 constellation.

The Gen2 satellites could improve Starlink coverage over lower latitude regions, and help alleviate pressure on the network from growing consumer uptake. SpaceX said last month the network has more than 1 million active subscribers. The Starlink spacecraft beam broadband internet signals to consumers around the world, connectivity that is now available on all seven continents with testing underway at a research station in Antarctica.

“Our action will allow SpaceX to begin deployment of Gen2 Starlink, which will bring next generation satellite broadband to Americans nationwide, including those living and working in areas traditionally unserved or underserved by terrestrial systems,” the FCC wrote in its Dec. 1 order partially approving the Starlink Gen2 constellation. “Our action also will enable worldwide satellite broadband service, helping to close the digital divide on a global scale.

“At the same time, this limited grant and associated conditions will protect other satellite and terrestrial operators from harmful interference and maintain a safe space environment, promoting competition and protecting spectrum and orbital resources for future use,” the FCC wrote. “We defer action on the remainder of SpaceX’s application at this time.”

Specifically, the FCC granted SpaceX authority to launch the initial block of 7,500 Starlink Gen2 satellites into orbits at 525, 530, and 535 kilometers, with inclinations of 53, 43, and 33 degrees, respectively, using Ku-band and Ka-band frequencies. The FCC deferred a decision on SpaceX’s request to operate Starlink Gen2 satellites in higher and lower orbits.

Like the first Gen2 launch last month, the Starlink 5-2 mission Thursday targeted the 530-kilometer-high (329-mile) orbit at an inclination of 43 degrees to the equator.

The Starlink 5-2 mission will add 56 more satellites to SpaceX’s Starlink internet network. Credit: Spaceflight Now

SpaceX currently has nearly 3,400 functioning Starlink satellites in space, with more than 3,100 operational and roughly 200 moving into their operational orbits, according to a tabulation by Jonathan McDowell, an expert tracker of spaceflight activity and an astronomer at the Harvard-Smithsonian Center for Astrophysics.

The first-generation Starlink network architecture includes satellites flying a few hundred miles up, orbiting at inclinations of 97.6 degrees, 70 degrees, 53.2 degrees, and 53.0 degrees to the equator. Most of SpaceX’s recent Starlink launches have released satellites into Shell 4, at an inclination of 53.2 degrees, after the company largely completed launches into the first 53-degree inclination shell last year.

Shell 5 of the Starlink network was widely believed to be one of the polar-orbiting layers of the constellation, at 97.6 degrees inclination. But the name of the first Gen2 missions — Starlink 5-1 and 5-2 — appear to suggest SpaceX has changed the naming scheme for the Starlink shells.

SpaceX’s launch team was stationed inside a launch control center just south of Cape Canaveral Space Force Station for Thursday’s predawn countdown. SpaceX began loading super-chilled, densified kerosene and liquid oxygen propellants into the Falcon 9 vehicle at T-minus 35 minutes.

Helium pressurant also flowed 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 were thermally conditioned for flight through a procedure known as “chilldown.” The Falcon 9’s guidance and range safety systems were also configured for launch.

After liftoff, the Falcon 9 rocket vectored its 1.7 million pounds of thrust — produced by nine Merlin engines — to steer southeast over the Atlantic Ocean. SpaceX has resumed launches this winter using the southeasterly corridor from Cape Canaveral, rather than trajectories to the northeast, to take advantage of better sea conditions for landing of the Falcon 9’s first stage booster.

Throughout the summer and fall, SpaceX launched Starlink missions on paths toward the northeast from Florida’s Space Coast.

The Falcon 9 rocket exceeded 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 separated from the Falcon 9’s upper stage, then fired pulses from cold gas control thrusters and extended titanium grid fins to help steer the vehicle back into the atmosphere.

Two braking burns slowed the rocket for landing on the drone ship “Just Read the Instructions” around 410 miles (660 kilometers) downrange approximately nine minutes after liftoff. The reusable booster, designated B1067 in SpaceX’s inventory, completed its ninth trip to space Thursday.

The Falcon 9’s reusable payload fairing jettisoned during the second stage burn. A recovery ship was also on station in the Atlantic to retrieve the two halves of the nose cone after they splash down under parachutes.

Landing of the first stage on Thursday’s mission occurred just as the Falcon 9’s second stage engine cut off to deliver the Starlink satellites into orbit.

Separation of the 56 Starlink spacecraft, built by SpaceX in Redmond, Washington, from the Falcon 9 rocket occurred 19 minutes after liftoff. SpaceX’s ground team waited to confirm the spacecraft deployment milestone when the rocket passed in range of a tracking station in Australia about an hour after liftoff.

The Falcon 9’s guidance computer aimed to deploy the satellites into an elliptical orbit at an inclination of 43 degrees to the equator, with an altitude ranging between 131 miles and 209 miles (212-by-337 kilometers). After separating from the rocket, the 56 Starlink spacecraft will unfurl solar arrays and run through automated activation steps, then use ion engines to maneuver into their operational orbit.

ROCKET: Falcon 9 (B1067.9)

PAYLOAD: 56 Starlink satellites (Starlink 5-2)

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

LAUNCH DATE: Jan. 26, 2023

LAUNCH TIME: 4:32:20 a.m. EST (0932:20 GMT)

WEATHER FORECAST: 70% chance of acceptable weather; Low to moderate risk of upper level winds; Low risk of unfavorable conditions for booster recovery

BOOSTER RECOVERY: “Just Read the Instructions” drone ship northeast of the Bahamas

LAUNCH AZIMUTH: Southeast

TARGET ORBIT: 131 miles by 209 miles (212 kilometers by 337 kilometers), 43.0 degrees inclination

LAUNCH TIMELINE:

  • T+00:00: Liftoff
  • T+01:12: Maximum aerodynamic pressure (Max-Q)
  • T+02:28: First stage main engine cutoff (MECO)
  • T+02:31: Stage separation
  • T+02:38: Second stage engine ignition
  • T+02:42: Fairing jettison
  • T+06:42: First stage entry burn ignition (three engines)
  • T+07:00: First stage entry burn cutoff
  • T+08:23: First stage landing burn ignition (one engine)
  • T+08:43: Second stage engine cutoff (SECO 1)
  • T+08:44: First stage landing
  • T+18:49: Starlink satellite separation

MISSION STATS:

  • 199th launch of a Falcon 9 rocket since 2010
  • 209th launch of Falcon rocket family since 2006
  • 9th launch of Falcon 9 booster B1067
  • 171st Falcon 9 launch from Florida’s Space Coast
  • 111th Falcon 9 launch from pad 40
  • 166th launch overall from pad 40
  • 141st flight of a reused Falcon 9 booster
  • 69th Falcon 9 launch primarily dedicated to Starlink network
  • 5th Falcon 9 launch of 2023
  • 6th launch by SpaceX in 2023
  • 5th orbital launch attempt based out of Cape Canaveral in 2023

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Follow Stephen Clark on Twitter: @StephenClark1.

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