SpaceX launches Starlink v1.0 L23 mission
SpaceX has launched another batch of 60 Starlink satellites on the Starlink v1.0 L23 mission.… The post SpaceX launches Starlink v1.0 L23 mission appeared first on NASASpaceFlight.com.
SpaceX has launched another batch of 60 Starlink satellites on the Starlink v1.0 L23 mission. Liftoff from Space Launch Complex 40 (SLC-40) at the Cape Canaveral Space Force Station occurred on time on April 7 at 12:34 PM EDT (16:34 UTC).
This was the third time a Falcon 9 first stage flew a seventh mission, the tenth Falcon 9 flight of the year, and the first in April. This flight is likely be the last SpaceX mission prior to the Crew-2 launch later this month.
Booster Reuse and Launch Preparation
SpaceX used a flight proven Falcon 9 Block 5 booster, B1058-7 – with the “-7” signifying the stage’s seventh flight. This was the third time a booster was used on a seventh flight.
B1058 is one of five Falcon 9 boosters introduced in 2020. It first supported the Crew Demo-2 mission in May 2020, becoming the first SpaceX rocket to launch crew into space. It then supported the ANASIS-II mission in July 2020, when it achieved the fastest Falcon 9 booster turnaround at the 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, B1058 supported the Transporter-1 rideshare mission in January and the Starlink v1.0 L20 mission in March.
This time, B1058 was turned around in 27 days and 8 hours. This makes Starlink v1.0 L23 the second fastest turnaround for Falcon 9, just barely beat by B1060 on the Starlink v1.0 L18 mission at 27 days and 4 hours.
However, this launch gives B1058 the fastest average turnaround time at 52 days. These fast turnaround records help SpaceX rapidly reuse Falcon 9 boosters in support of Starlink and other missions.
B1058 successfully landed on the SpaceX autonomous spaceport drone ship Of Course I Still Love You (OCISLY), which was stationed ~633 kilometers downrange. OCISLY left Port Canaveral on April 3 to support Starlink v1.0 L23.
Technicians working on JRTI and the crew of Tug Hawk watch as Falcon 9 lofts another 60 Starlink satellites into space. B1058-7 landed onboard OCISLY 633km downrange as stage two continues towards orbit. #SpaceX
Wrap-up: https://t.co/NciRZpqDid pic.twitter.com/Fk3X4dVfLi
— Julia (@julia_bergeron) April 7, 2021
This mission also used a flight proven set of payload fairings. One fairing 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 a fairing half has flown four missions.Falcon 9/Starlink v1.0 L23 UPDATES
Once the fairings separate from the Falcon 9, they will be recovered by the fairing recovery vessel Shelia Bordelon.
This time around, SpaceX did not conduct a static fire test prior to launch. Since Starlink v1.0 L8 with B1059-3, several missions have not required a static fire test due to the reliability of the flight proven first stage boosters. For non-Starlink missions, the launch customer can request a static fire test before a launch.
At T-38 minutes, a final Go/No-Go poll was conducted for propellant loading. Three minutes later, the auto-launch sequence started, beginning RP-1 fuel and Liquid Oxygen (LOX) loading on the first stage and RP-1 loading on 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 began engine chill to ensure there were no thermal shocks to the engines at ignition. At T-4 minutes, the transporter/erector retracted to 88.2 degrees for launch.
All propellant loading completed at T-2 minutes. At T-1 minute, Falcon 9 entered “startup” and the flight computer took control of the countdown. At the same time, both stages began to pressurize for flight.
Three seconds before liftoff, the engine controller commanded the first stage engines to ignite.
Once its engines were at full thrust and verified to be healthy, the hydraulic hold-down clamps released the Falcon 9, and the transporter/erector retracted to 45 degrees as the vehicle lifted off.
A few seconds later, the Falcon 9 began a pitch program to fly northeast from Cape Canaveral towards a 53 degree inclined orbit. At T+1 minute 12 seconds, the Falcon 9 reached Max-Q, where the aerodynamic forces were at their peak.
At T+2 minutes 33 seconds, the nine first-stage engines shut down, followed by stage separation a few seconds later. The single Merlin Vacuum engine on the second stage then ignited.
The first stage then deployed its grid fins and began a flip maneuver to prepare for re-entry. At around T+3 minutes, the payload fairings separated.
After six minutes into the flight, the first stage reignited three of its engines to slow down and protect itself from reentry. The entry burn lasted around 20 seconds.
A couple of minutes later, the first stage reignited a single engine and landed on OCISLY. This was the 79th first stage landing for Falcon 9. The first stage will now be taken back to Port Canaveral to begin inspections and refurbishments for its eighth flight.
While the first stage was landing, the second stage shut down its engine and entered its initial parking orbit. It then restarted for 1 second. That second burn placed the Falcon 9 and 60 Starlink satellites into am approximate 260 x 296 kilometer orbit.
After the burn was complete, the second stage began a slow spin in preparation for Starlink deployment. After the spin has started and another 15-minute coast is complete, the 60 Starlink satellites separated from the second stage.
The newly launched Starlink satellites will now begin activation and maneuvering to their operational 550 kilometer operational orbits and planes.
Starlink is SpaceX’s low Earth orbit satellite internet constellation that aims to deliver fast, affordable, and low latency service where internet is currently either unavailable or expensive.
The Starlink constellation is set to consist of five orbital shells, with the Starlink v1.0 L23 mission continuing to build the first. This shell will consist of 1,584 satellites in the aforementioned 550 kilometer altitude, 53 degree inclination orbit. The first of these satellites were launched in November 2019, and the first shell will be completed with the Starlink v1.0 L28 mission.
Once the shell is complete, Starlink will provide coverage to over 80% of the Earth’s surface.
Each of the v1.0 Starlink satellites weighs 260 kilograms 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 launched into space, of which 1,319 are still in orbit.
Starlink v1.0 L23 will likely be the final launch before SpaceX begins to focus on the Crew-2 mission, lifting off from LC-39A on April 22.
(Lead photo of B1058-7 launching the Starlink v1.0 L23 mission – via Stephen Marr for NSF)
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