SpaceX has launched another batch of 60 Starlink satellites on the Starlink v1.0 L23 mission. Lift from Space Launch Complex 40 (SLC-40) at Cape Canaveral Space Force Station took place on time on April 7 at. 12:34 EDT (16:34 UTC).
This was the third time that a first phase of the Falcon 9 flew a seventh mission, this year’s tenth Falcon 9 flight and the first in April. This flight is likely to be the last SpaceX mission before the Crew-2 launch later this month.
Preparation of recycling and launch of boosters
SpaceX used a flight-tested Falcon 9 Block 5 booster, B1
The B1058 is one of five Falcon 9 boosters introduced in 2020. It first supported the Crew Demo-2 mission in May 2020 and became the first SpaceX rocket to launch the crew into space. It then supported the ANASIS-II mission in July 2020, when it achieved the fastest Falcon 9 booster cycle at that time with 51 days between launches.
It later supported the Starlink v1.0 L12 mission in October 2020, followed by the SpaceX CRS-21 mission in December 2020, the first launch of a Cargo Dragon 2 spacecraft. In 2021, the B1058 Transporter-1 supported the rideshare mission in January and the Starlink v1.0 L20 mission in March.
This time, B1058 was reversed in 27 days and 8 hours. This makes the Starlink v1.0 L23 the second fastest turnaround for the Falcon 9, just barely beaten by the B1060 on the Starlink v1.0 L18 mission in 27 days and 4 hours.
However, this launch gives the B1058 the fastest average delivery time of 52 days. These fast turnaround records help SpaceX quickly reuse Falcon 9 boosters in support of Starlink and other missions.
B1058 successfully landed on the SpaceX autonomous space drone ship Of course I still love you (OCISLY), which was stationed ~ 633 kilometers down. OCISLY left Port Canaveral on April 3 to support Starlink v1.0 L23.
Technicians working on the JRTI and crew on the Tug Hawk are watching as the Falcon 9 lifts another 60 Starlink satellites into space. B1058-7 landed aboard OCISLY 633 km downhill as stage two continues towards orbit. #SpaceX
Exit: https://t.co/NciRZpqDid pic.twitter.com/Fk3X4dVfLi
– Julia (@julia_bergeron) April 7, 2021
This mission also used a proven set of payload curves. One half, the passive half, supported the Starlink v1.0 L12 mission in October 2020.
The other half, the active half, supported the AMOS-17 mission in August 2019, the Starlink v1.0 L6 mission in April 2020 and the Starlink v1.0 L15 mission in November 2020. This was the second time that a fairing half flew four missions.
Once the fairings are separated from the Falcon 9, they will be restored by the fairing recovery ship Shelia Bordelon.
This time, SpaceX did not perform a static fire test before launch. Since Starlink v1.0 L8 with B1059-3, several missions have not required a static fire test due to the reliability of the flown, first stage boosters. For non-Starlink missions, the launch customer may request a static fire test prior to launch.
In the T-38 minutes, a final Go / No-Go vote on fuel load was conducted. Three minutes later, the automatic launch sequence started, in which RP-1 fuel and liquid oxygen (LOX) were filled in the first stage, and RP-1 load in the second stage.
Second stage RP-1 loading completed at T-20 minutes before LOX loading began at T-16 minutes.
At T-7 minutes, the Falcon 9 engine chill began to ensure that there were no thermal shocks to the engines upon ignition. In T-4 minutes, the conveyor / erector retreated to 88.2 degrees for launch.
All refueling completed at T-2 minutes. In the T-1 minute, the Falcon 9 went to “startup”, and the aircraft computer took control of the countdown. At the same time, both stages began to put pressure on the plane.
Three seconds before departure, the engine control commanded the engines in the first stage to ignite.
When the engines were at full speed and confirmed to be healthy, the hydraulic hold-down clamps released the Falcon 9 and the conveyor / erector retracted to 45 degrees as the vehicle lifted off.
A few seconds later, the Falcon 9 began a tone program to fly northeast from Cape Canaveral toward a 53-degree oblique orbit. At T + 1 minute 12 seconds, the Falcon 9 reached the Max-Q, where aerodynamic forces were at their peak.
At T + 2 minutes and 33 seconds, the nine first-stage motors shut down, followed by stage separation a few seconds later. The only Merlin Vacuum engine on the second stage then switched on.
The first phase then rolled out its lattice fins and began a flip-maneuver to prepare for re-entry. About T + 3 minutes the payload screens were separated.
After six minutes out of flight, the first phase revived three of its engines to brake and protect itself from re-entry. The inlet combustion lasted about 20 seconds.
A few minutes later, the first stage repeated a single engine and landed on OCISLIGT. This was the 79th first stage landing for Falcon 9. The first stage will now be taken back to Port Canaveral to start inspections and renovations for its eighth flight.
While the first stage landed, the second stage shut down the engine and went into its original parking lot. Then it restarted for 1 second. The second combustion placed the Falcon 9 and 60 Starlink satellites in a circle of approx. 260 x 296 kilometers.
After the combustion was completed, the second phase began a slow spin in preparation for the implementation of Starlink. After the spin-off has started and another 15-minute coastline is completed, the 60 Starlink satellites are separated from the second stage.
The newly launched Starlink satellites are now beginning activation and maneuvering for their operational 550 kilometers of operational orbits and aircraft.
Starlink is SpaceX’s low earth satellite satellite constellation, which aims to provide fast, affordable and low latency service, where internet is currently either inaccessible or expensive.
The Starlink constellation consists of five orbital shells, with the Starlink v1.0 L23 mission continuing to build the first. This shell consists of 1,584 satellites at the above 550 kilometers altitude, 53 degree orbit. The first of these satellites was launched in November 2019 and the first is to be completed with the Starlink v1.0 L28 mission.
When the shell is finished, Starlink will provide coverage for over 80% of the earth’s surface.
Each of the v1.0 Starlink satellites weighs 260 kg and is designed to be compact. The satellites are equipped with a Hall-effect Krypton Ion Thruster to maneuver in space.
Since May 2019, 1,445 Starlink satellites have been launched into space, of which 1,319 are still in orbit.
The Starlink v1.0 L23 will likely be the latest launch before SpaceX begins focusing on the Crew-2 mission and launches from the LC-39A on April 22nd.
(Lead photo of B1058-7 launch of Starlink v1.0 L23 mission – via Stephen Marr to NSF)