Rapid Starlink launch cadence continues with Group 2-5 mission

by Thomas Burghardt

The second of two Starlink launches this week, Starlink Group 2-5, launched at 11:12 AM PST (19:12 UTC) on Friday, Feb. 17 from Space Launch Complex 4 East (SLC-4E) at Vandenberg Space Force Base in California.

The first mission of the week, Starlink Group 5-4, lifted off at 12:10 AM EST (05:10 UTC) on Sunday, Feb. 12. That mission broke the pad turnaround record for both Space Launch Complex 40 (SLC-40) at Cape Canaveral Space Force Station in Florida and the overall record across all three Falcon 9 launch pads.

SpaceX Breaking Launch Cadence Records

In 2022, SpaceX launched 61 missions into orbit, breaking the company’s previous record of 31 missions set in 2021. So far in 2023, the company is on pace to break its own record again. Based on the launch cadence achieved in January and early February, SpaceX could easily pass the 80-launch mark this year.

SpaceX CEO Elon Musk had stated that the company was “aiming for up to 100 flights” in 2023, but factors such as launch pad and drone ship turnaround times make such a goal difficult, at least for now. With Starship likely to make its first orbital launch attempt in the coming months, the possibility of over 100 missions launched by SpaceX within a calendar year may be even more feasible by 2024.

With the launch of Starlink Group 5-4, liftoff occurred five days, three hours, and 38 minutes after the Amazonas Nexus mission. This breaks SpaceX’s previous pad turnaround record which was also set at SLC-40, with just five days, nine hours, and 28 minutes between Hotbird-13F and Starlink Group 4-36 in October 2022.

SLC-40 has, so far, facilitated the fasted pad turnarounds of the three Falcon 9 launch sites. Launch Complex 39A (LC-39A) at the Kennedy Space Center has supported two launches with as little as eight days, 23 hours, and five minutes between liftoffs, between the OneWeb-15 and Starlink Group 4-37 missions in December 2022. This launch pad is occasionally limited to slightly longer turnaround times as a result of ground-side reconfigurations to support Dragon and Falcon Heavy missions, which currently only launch from LC-39A.

The current turnaround record at Vandenberg’s SLC-4E sits at 11 days and 16 hours, achieved between the Starlink Group 3-1 and 3-2 missions in July 2022. Friday’s Group 2-5 mission did not break this record, with a turnaround of 17 days, two hours, and 57 minutes.

The previous mission from SLC-40, Amazonas Nexus, streaks to orbit. (Credit: Stephen Marr for NSF)

The demand for this kind of launch cadence is being driven by the company’s Starlink satellite internet constellation, which is being supported by the pair of Falcon 9 launches this week. Early Starship launches will also likely be leveraged to deploy upgraded Starlink satellites and gain flight experience ahead of Human Landing System (HLS) missions for NASA’s Artemis program, including orbital refilling missions that will also require a rapid launch cadence.

Starlink Group 5-4

The Group 5-4 mission carried 55 Starlink satellites. These satellites are believed to be version 1.5 of the spacecraft, improved from the original Starlink satellites but not yet the version intended to leverage Starship’s launch capabilities. Group 5 missions deploy satellites into orbits reserved for the second generation Starlink constellation, but so far have been limited to this “F9-1” satellite configuration.

Future launches to the Starlink Gen2 constellation may use the F9-2 configuration, which are larger satellites modified to be launched on Falcon 9. Once Starship is ready to carry and deploy payloads, the full-size Starlink Gen2 satellites can be launched.

Sunday’s mission targeted an initial deployment orbit of 298 by 339 kilometers, at an inclination of 43 degrees. Falcon 9’s upper stage delivered the satellites to this orbit via two burns, one to reach an initial parking orbit, and another after a coast phase to raise the orbital perigee. With the satellites deployed, they will soon undergo solar array deployments and initial checkouts.

Satellites that are operating properly will maneuver themselves up to the operational altitude of 530 kilometers. Any satellites not functioning properly will naturally decay from the lower orbit and be safely destroyed upon reentry.

The first stage of Falcon 9 supporting the Group 5-4 mission was B1062-12. This booster began its career with two GPS satellite launches, lofting GPS-III-SV04 in November 2020 and GPS-III-SV05 in June 2021. B1062 has also supported two private crew missions, Inspiration4 and Axiom-1, the Nilesat-301 communications satellite mission, and six previous Starlink launches.

After the initial ascent, B1062 descended toward A Shortfall of Gravitas, one of SpaceX’s autonomous spaceport drone ships stationed downrange in the Atlantic Ocean. The payload fairings, separated from the upper stage shortly after stage separation, splashed down for recovery by SpaceX multi-purpose vessel Doug.

Falcon 9’s upper stage conducts a deorbit burn after payload deployment, reentering over the ocean south of Africa.

Starlink Group 2-5

The second Starlink mission of the week carried 51 Starlink satellites destined for the Gen1 constellation. The stack was deployed into an orbital inclination of 70 degrees. Once checked out in the initial 222 by 335 km orbit, the satellites will maneuver to an operational altitude of 570 km.

The first stage, B1063-9, previously supported the Sentinel-6A and DART missions, as well as six previous Starlink flights. It made a landing on Of Course I Still Love You after launch, while the payload fairings headed for a splashdown recovery by NRC Quest. The upper stage conducted a single burn before payload deployment, and another to destructively deorbit.

With this duo of Starlink missions are off the ground, the Falcon teams have customer missions to launch in the near term, including the Inmarsat I-6 F2 communications satellite launch, slated for no earlier than Feb. 17, and the Crew-6 mission carrying four astronauts to the International Space Station no earlier than Feb. 26.

(Lead photo: Falcon 9 launches the Starlink Group 5-4 mission. Credit: Stephen Marr for NSF)

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