Watch a replay of our live coverage of the countdown and launch of a SpaceX Falcon 9 rocket on the Starlink 6-4 mission at 8:20 a.m. EDT (1220 UTC) on June 4 from Space Launch Complex 40 at Cape Canaveral Space Force Station, Florida. Follow us on Twitter.
SpaceX launched a Falcon 9 rocket from Cape Canaveral Sunday morning with 22 upgraded Starlink internet satellites, but officials called off a second Falcon 9 launch later in the day due to high winds in the booster’s offshore recovery area.
The 229-foot-tall (70-meter) Falcon 9 rocket took off from pad 40 at Cape Canaveral Space Force Station at 8:20 a.m. EDT (1220 UTC), lofting 22 second-generation Starlink internet satellites into orbit on a mission SpaceX called Starlink 6-4.
Final launch preps ran behind schedule Sunday morning, forcing a delay of about two-and-half hours for the Starlink 6-4 launch.
Less than four hours later, another Falcon 9 was set for liftoff a few miles up the coast from pad 39A at NASA’s Kennedy Space Center. But SpaceX scrubbed the launch attempt, delaying liftoff until Monday because of high winds in the downrange landing zone for the Falcon 9’s first stage booster.
When it takes off, that mission will send an unpiloted Cargo Dragon supply ship on a flight to the International Space Station.
The Starlink 6-4 mission continued launching SpaceX’s new Starlink V2 Mini satellite platform fitted with improved phased array antennas, capable of four times the communications capacity of earlier generations of Starlink satellites, known as Version 1.5. The Starlink satellites beam internet signals to consumers around the world.
SpaceX delayed the Starlink 6-4 mission from June 1 after a transporter carrying the Falcon 9’s payload fairing containing the batch of Starlink satellites ran into an electrical line at the Florida spaceport. The incident briefly knocked out electricity at Kennedy Space Center on May 27, and power flashes were visible in the sky over the launch base.
The transporter was carrying the Starlink satellites inside their payload fairing from a processing facility to the Falcon 9’s hangar at pad 40. It wasn’t clear whether SpaceX swapped out the Starlink satellites and payload fairing that struck the electrical lines for a new set of spacecraft. The payload fairing containing the satellites that launched Sunday traveled from SpaceX’s Roberts Road facility at Kennedy Space Center to the hangar at pad 40 on Friday.
SpaceX technicians at the pad 40 hangar rotated the fairing horizontal and connected it with the Falcon 9 rocket, then rolled the entire launch vehicle to the pad and raised it vertical in preparation for Sunday morning’s countdown.
Despite their name, the Starlink V2 Mini satellites are nearly times as massive and more than four times larger than the older Starlink V1.5 satellites. Like all Starlink launches, the Falcon 9 rocket released the new batch of internet satellites into an orbit below their final operating altitude. The satellites will then use on-board propulsion to raise their orbits to an altitude of more than 300 miles (500 kilometers).
The “Mini” moniker refers to SpaceX’s plans to launch an even larger full-size Starlink V2 satellite design on the company’s huge new Starship rocket. The Starship has nearly 10 times the payload lift capability of a Falcon 9 rocket, with greater volume for satellites, too.
The full-size Starlink V2s will be capable of transmitting signals directly to cell phones. But with the Starship rocket not yet operational following its first full-scale test flight in April, SpaceX began launching second-generation satellites on Falcon 9 rockets and developed the V2 Minis to fit on the company’s existing launch vehicles.
The first group of 21 Starlink V2 Mini satellites launched Feb. 27 on a Falcon 9 rocket, but some of those spacecraft were decommissioned and intentionally steered back into the atmosphere due to technical problems. Elon Musk, SpaceX’s founder and CEO, said the first batch of Starlink V2 Mini satellites were “experiencing some issues, as expected.” SpaceX planned to thoroughly test the satellites before boosting them above the altitude of the International Space Station to their final operating orbit.
SpaceX continued launching older-model Starlink V1.5 satellites on a series of missions in March and April, before resuming deployment of the bigger, more capable Starlink V2 Mini satellites with a Falcon 9 launch April 19. Since then, SpaceX has launched four missions with the older Starlink V1.5 satellites before switching back to the larger V2 Minis again for a May 19 launch.
In addition to improved communications capability, the Starlink V2 Mini satellites have more efficient, higher-thrust argon-fueled propulsion systems. Argon is cheaper than the krypton gas SpaceX used to fuel ion engines on the older-generation Starlink V1.5 satellites.
“This means Starlink can provide more bandwidth with increased reliability and connect millions of more people around the world with high-speed internet,” SpaceX said before the first launch of Starlink V2 Mini satellites in February.
Each Starlink V2 Mini satellite weighs about 1,760 pounds (800 kilograms) at launch, nearly three times heavier than the older Starlink satellites. The are also bigger in size, with a spacecraft body more than 13 feet (4.1 meters) wide, filling more of the Falcon 9 rocket’s payload fairing during launch, according to regulatory filings with the Federal Communications Commission.
The larger, heavier satellite platform means a Falcon 9 rocket can only launch around 22 Starlink V2 Mini payloads at a time, compared to more than 50 Starlink V1.5s on a single Falcon 9 launch.
The two deployable solar panels on each Starlink V2 Mini satellite span about 100 feet (30 meters) tip-to-tip. The previous generation of Starlink V1.5 satellites have a single solar array wing, with each spacecraft measuring about 36 feet (11 meters) end-to-end once the solar panel is extended.
The enhancements give the Starlink V2 Mini satellites a total surface area of 1,248 square feet, or 116 square meters, more than four times that of a Starlink V1.5 satellite.
The Federal Communications granted SpaceX approval Dec. 1 to launch up to 7,500 of its planned 29,988-spacecraft Starlink Gen2 constellation, which will spread out into slightly different orbits than the original Starlink fleet. The regulatory agency deferred a decision on the remaining satellites SpaceX proposed for Gen2.
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. SpaceX started launching older-design Starlink V1.5 satellites into the orbits approved for the Gen2 constellation in December.
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. SpaceX is nearing completion with launches to populate the first-generation Starlink network.
With the launch Sunday, SpaceX has sent 528 Starlink Gen2 satellites into orbit, including Starlink V1.5 and Starlink V2 Mini spacecraft. After this mission, SpaceX has deployed 4,543 Starlink satellites in all, including test units no longer in service. More than 4,200 Starlink satellites are currently in orbit, according to Jonathan McDowell, an astrophysicist and space expert who catalogs spaceflight activity.
Liftoff of SpaceX’s Falcon 9 rocket with 22 upgraded Starlink internet satellites, kicking off what SpaceX hopes will be a Falcon 9 launch doubleheader today on Florida’s Space Coast. https://t.co/m07MANNG45 pic.twitter.com/DzziiRC3pZ
— Spaceflight Now (@SpaceflightNow) June 4, 2023
During the Sunday’s early morning countdown, SpaceX’s launch team was stationed inside a launch control center just south of Cape Canaveral Space Force Station to monitor key systems on the Falcon 9 rocket and at the launch pad. 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. 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 400 miles (640 kilometers) downrange approximately eight-and-a-half minutes after liftoff. The reusable booster, designated B1078 in SpaceX’s inventory, flew on its third trip to space Sunday.
Falcon 9’s first stage booster landed on a drone ship northeast of the Bahamas, completing the third flight for this reusable booster.
— Spaceflight Now (@SpaceflightNow) June 4, 2023
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 Sunday’s mission occurred just as the Falcon 9’s second stage engine cut off to deliver the Starlink satellites into a preliminary parking orbit. After flying halfway around the world, another upper stage burn 54 minutes into the mission reshaped the orbit ahead of payload separation.
Separation of the 22 Starlink spacecraft, built by SpaceX in Redmond, Washington, from the Falcon 9 rocket was confirmed about 65 minutes after liftoff.
The Falcon 9’s guidance computer aimed to deploy the satellites into an orbit at an inclination of 43 degrees to the equator, with an altitude ranging between 195 miles and 200 miles (314-by-323 kilometers). After separating from the rocket, the 22 Starlink spacecraft will unfurl solar arrays and run through automated activation steps, then use their argon-fueled ion engines to maneuver into their operational orbit.
ROCKET: Falcon 9 (B1078.3)
PAYLOAD: 22 Starlink V2 Mini satellites (Starlink 6-4)
LAUNCH SITE: SLC-40, Cape Canaveral Space Force Station, Florida
LAUNCH DATE: June 4, 2023
LAUNCH TIME: 8:20 a.m. EDT (1220 UTC)
WEATHER FORECAST: 15% chance of acceptable weather; Low 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: 195 miles by 200 miles (314 kilometers by 323 kilometers), 43.0 degrees inclination
- T+00:00: Liftoff
- T+01:12: Maximum aerodynamic pressure (Max-Q)
- T+02:32: First stage main engine cutoff (MECO)
- T+02:35: Stage separation
- T+02:42: Second stage engine ignition (SES 1)
- T+03:08: Fairing jettison
- T+06:16: First stage entry burn ignition (three engines)
- T+06:34: First stage entry burn cutoff
- T+08:07: First stage landing burn ignition (one engine)
- T+08:28: First stage landing
- T+08:44: Second stage engine cutoff (SECO 1)
- T+54:22: Second stage engine ignition (SES 2)
- T+54:24: Second stage engine cutoff (SECO 2)
- T+1:05:02: Starlink satellite separation
- 229th launch of a Falcon 9 rocket since 2010
- 240th launch of Falcon rocket family since 2006
- 3rd launch of Falcon 9 booster B1078
- 170th flight of a reused Falcon booster
- 193rd SpaceX launch from Florida’s Space Coast
- 127th Falcon 9 launch from pad 40
- 182nd launch overall from pad 40
- 87th Falcon 9 launch primarily dedicated to Starlink network
- 35th Falcon 9 launch of 2023
- 38th launch by SpaceX in 2023
- 27th orbital launch attempt based out of Cape Canaveral in 2023
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Follow Stephen Clark on Twitter: @StephenClark1.