On the two main coasts of the United States, SpaceX launched a number of low Earth orbit communications satellites for three different networks.
The first launch, Starlink Group 6-3, flew on Friday, May 19 at 2:19 AM EDT (06:19 UTC) from Space Launch Complex 40 (SLC-40) at the Cape Canaveral Space Force Station in Florida. The launch was just over five days after the last flight from the same pad. This broke the pad’s turnaround time between launches that was set between the Amazonas Nexus and Starlink 5-4 launches earlier this year. The previous turnaround record time was five days, three hours, and 38 minutes.
The second launch occurred on Saturday from Vandenberg, with Falcon 9 launching Iridium and OneWeb satellites.
Fast turnarounds between launches from the same pad are important to keeping up SpaceX’s current launch cadence.
Twenty-two Starlink v2 Mini satellites were launched on a southeast trajectory inclined 43 degrees to the equator. They were inserted into an initial orbit of 344 km by 353 km. The satellites will be boosted to their operational 530 km circular orbits in the coming weeks and months using their onboard argon ion thrusters.
View of a stack of 21 Starlink v2 Mini satellites before being enclosed in their fairing ahead of a previous launch. (Credit: SpaceX)
Starlink 6-3 used B1076 on its fifth flight, which marked the 30th Falcon 9 and 32nd orbital launch for SpaceX in 2023. The booster landed on the drone ship A Shortfall of Gravitas positioned 636 km downrange in the Atlantic. This core has previously flown the CRS-26, OneWeb #16, Starlink 6-1, and Intelsat 40e/TEMPO missions.
This same booster is also scheduled to be converted to a Falcon Heavy side booster for use on the Echostar 24 (Jupiter 3) mission set for no earlier than this coming August. Falcon 9 boosters can be converted into Falcon Heavy side boosters, and the reverse is also true.
A day after Starlink 6-3’s launch, another Falcon 9 launched from Space Launch Complex 4E (SLC-4E) at Vandenberg Space Force Base in California.
B1063’s 11th flight was the 31st Falcon 9 flight of this year, and SpaceX’s 33rd flight of 2023. The flight landed on the drone ship Of Course I Still Love You stationed in the Pacific Ocean, after flying a polar trajectory to the south, carrying five Iridium NEXT and 16 OneWeb satellites on board.
The five Iridium NEXT satellites will act as replacements for some of the satellites SpaceX launched for the company between 2017 and 2019. The constellation consists of 66 operational satellites, nine on-orbit spares, and six ground spares.
The OneWeb second generation demonstrator “JoeySat” developed with assistance from ESA and the UK Space Agency. (Credit: ESA)
Though OneWeb’s initial operational constellation of 618 satellites is now in orbit, 16 satellites will be flown on this mission. 15 of these satellites, of the same type as the operational satellites, will become on-orbit spares, while one of the satellites is a second-generation demonstrator spacecraft, known as “JoeySat.”
The Iridium/OneWeb launch will be the second flight for the new, shortened second-stage engine nozzle. The shorter nozzle, designed to reduce costs and increase launch cadence, made its debut on the Transporter-7 launch in April. The shortened nozzle slightly reduces performance, so it will only be used on missions that do not need Falcon 9’s full performance capability.
For this flight, the total payload mass is 6,600 kg, as opposed to the 17,600 kg for the Starlink 6-3 launch. The Iridium Next satellites will be placed in an initial 615 km circular orbit inclined 86.4 degrees to the Equator, while the OneWeb satellites use a 1,200 km circular orbit inclined 87.9 degrees to the Equator.
The Iridium satellites will be moved up to 625 km for checkouts, and one of them will move to its operational orbit at 760 km altitude. The other four satellites will be placed into different orbital planes at 625 km.
The pair of launches is scheduled to be followed by the Axiom-2 crewed spaceflight from Launch Complex 39A at the Kennedy Space Center the following week as SpaceX attempts to fly up to 100 orbital missions this year.
(Lead image: Falcon 9 launches latest Starlink mission. Photo: Julia Bergeron for NSF)