SpaceX launched the primary of two Starlink missions from each coasts inside the week. The primary launch, Starlink Group 2-10 launched aboard a Falcon 9 from Space Launch Complex 4E (SLC-4E) situated on the Vandenberg Space Force Base (VSFB) in California with a T0 of 11:02 PM PDT Tuesday, May 30 (06:02 UTC May 31).
The following launch, Starlink Group 6-4, is currently scheduled to launch from Space Launch Complex 40 (SLC-40) on the Cape Canaveral Space Force Station Thursday, June 4 – with a lot of launch windows available throughout the morning.
Each missions will proceed to grow SpaceX’s web satellite network in low-Earth orbit. Earlier this month, SpaceX surpassed 4,000 of those satellites in orbit, with that number growing continually.
There can be two different variants of satellites launching.
The primary mission, Group 2-10, used a rather older variant of satellites generally known as v1.5. It continues to be using a few of the features within the upgraded v2 satellites, including laser-link communications between satellites. They do, nevertheless, use a hall effect thruster powered by krypton and every satellite only masses roughly 300 kilograms. For comparison, the brand new v2 Mini satellites have a mass of over 800 kilograms.
The 6-4 mission can be launching the aforementioned “v2 Mini” satellites since the expected full-sized upgraded satellites were meant to fly on Starship. With just one test flight of Starship currently under its belt, SpaceX worked with the Federal Communications Commission to permit smaller versions to be launched contained in the fairing of the Falcon 9. With these still being quite large, fewer v2 mini satellites are launched without delay.
The v2 Mini variants still contain many of the upgrades that may fly on the usual v2 satellites. These include providing 4 times more capability than the sooner v1.5 satellites in addition to using argon for the hall effect thrusters aboard each satellite. SpaceX adds that every latest v2 Mini launch will introduce more capability into the general system.
A Starlink v1.5 satellite (left) in comparison with a Starlink 1.0 satellite (right). (Credit: SpaceX)
The primary launch, Group 2-10, carrying 52 v1.5 satellites, flew aboard booster B1061-14, which previously flew on Crew-1, Crew-2, SXM-8, CRS-23, IXPE, Transporter-4, Globalstar FM15, Eros-C3, and 4 Starlink missions. This mission launched on a southern trajectory, including a slight curve to go around populated areas resembling Los Angeles.
As with other group two launches from VSFB, the satellites deploy at an initial 222 by 333 kilometers orbit inclined 70 degrees, eventually using its thrusters to finish in a 530-kilometer circular orbit also inclined 70 degrees.
Meanwhile, the primary stage landed back on the drone ship Of Course I Still Love You shortly after its launch. The drone ship was positioned along the western side of the Baja Peninsula.
View of a stack of 21 Starlink v2 Mini satellites before being enclosed of their fairing. (Credit: SpaceX)
The second launch is the Group 6-4 mission from Florida. The 22 Starlink v2 Mini satellites are scheduled to launch aboard B1078, which has flown two previous flights including Crew-6 in March sending astronauts to the International Space Station and O3b mPOWER 3 & 4 which launched in late April.
This mission can be launching in a southeastern direction, with an expected circular orbit of 530 kilometers inclined 43 degrees. The expected initial parking orbit is 365 by 373 kilometers inclined 43 degrees as seen during previous v2 Mini launches from SLC-40 and these satellites will use their argon hall effect thrusters to enter their final orbit.
This booster is anticipated to land on the drone ship Just Read The Instructions, which is situated roughly 640 kilometers downrange.
A Falcon 9 stands at SLC-4E on the Vandenberg Space Force Base. (Credit: Jack Beyer for NSF)
The countdown procedure for each launches could be very similar. 35 minutes before liftoff, equipment on the launch pad begins to load the Falcon 9 with RP-1 fuel, a kind of refined kerosene. At the identical time, liquid oxygen (LOX), the oxidizer for the Falcon fleet of rockets, begins loading into the primary stage.
Sixteen minutes until liftoff, LOX load gets underway on the second stage. Seven minutes before launch, the engines are chilled to prime them ahead of the supercooled cryogenics that flows through them at liftoff. This prevents a potentially dangerous shock at ignition.
There’s a slight difference at this point. The transporter erector (T/E) used at SLC-4E is an older variant. Consequently, it retracts 13 degrees away from the rocket minutes before liftoff and stays there through the launch. Nonetheless, at SLC-40 the T/E is retracted a couple of degrees prior to launch before it “throws back” as Falcon 9 lifts off.
Falcon 9 launches from SLC-4E on the Vandenberg Air Force Base, with the older-style T/E in use. (Credit: SpaceX)
At T-1 minute, Falcon 9 goes into “startup,” meaning the onboard computers have full control of the countdown because the propellant tanks are pressurized for flight. At T-3 seconds, the command is given to ignite the nine Merlin 1-D engines at the bottom of the primary stage followed by liftoff at T0.
About two and a half minutes into flight, major events will occur in quick succession for each flights. The primary stage engines will shut down after which separate from the second stage. That’s followed by the ignition of the only Merlin Vacuum engine which can burn until it places the satellites of their initial parking orbit.
A flown booster lands safely on the drone ship A Shortfall of Gravitas. (Credit: NASA)
Meanwhile, the boosters will execute a set of multiple burns, landing them on their respective drone ships just minutes after launching.
These launches will mark the 36th and 37th orbital launch attempts by SpaceX to this point this yr, including Falcon 9 and Falcon Heavy.
