SpaceX to launch its first of three missions for OneWeb

SpaceX is gearing up for its 55th flight of the year which will take the OneWeb Flight #15 mission using a flight-proven Falcon 9 to a polar low Earth orbit (LEO) from Launch Complex 39A (LC-39A) at the Kennedy Space Center (KSC) in Florida. Liftoff is scheduled for Dec. 8 at 5:27 PM EST (22:27 UTC).

Space Launch Delta 45 predicts a 10% chance of violating weather criteria on Dec. 8 and a less than 10% chance of violating weather constraints for a 24-hour delay if needed.

OneWeb Flight #15 is the first of three missions for OneWeb by SpaceX and will mark OneWeb’s third overall mission in 2022. Additionally, this launch will mark the third launch vehicle OneWeb has flown on.

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As a staple of SpaceX’s historic 55-launch year, this mission will use a flight-proven first-stage booster, B1069, on its fourth flight. B1069 is a newer booster, first introduced on the SpaceX CRS-24 mission in December 2021. After taking damage during transportation back to Port Canaveral following CRS-24, B1069 didn’t fly again until Starlink Group 4-23, 250 days later. B1069 supported one more flight during the Hotbird-13F mission in October 2022.

After lifting the second stage and Hotbird-13F out of the atmosphere, B1069 landed on the SpaceX Autonomous Spaceport Droneship (ASDS) Just Read The Instructions (JRTI). On Oct. 19, JRTI and B1069 returned to Port Canaveral. A few days later, SpaceX lowered B1069 horizontally and moved it to HangarX for refurbishments.

Arrival! SpaceX Falcon 9 B1069 returns to Port Canaveral + two fairing halves on Bob!https://t.co/icguJj6CpG pic.twitter.com/wp6FJMnpRc

— Gav Cornwell (@SpaceOffshore) October 20, 2022

After refurbishments, SpaceX moved B1069 to the horizontal integration facility (HIF) at LC-39A where they completed the Falcon 9 stack and attached the payload to the rocket.

This launch will be the first time a rocket uses the polar launch corridor from LC-39A.

In preparation for OneWeb Flight #15, SpaceX converted the transporter/erector (T/E) for a Falcon 9 with a payload fairing. The T/E picked up its reaction frame on Dec. 4 and rolled to the HIF to receive the Falcon 9. On the same day, SpaceX support ship Doug departed Port Canaveral and stationed itself ~600 km downrange to recover the payload fairings. As B1069 will be attempting to land on Landing Zone-1 (LZ-1), no drone ship was sent out to sea.

With the Falcon 9 stack on the T/E, SpaceX rolled the stack out to the launch site and went vertical.

Final launch preparations begin at T-38 minutes, with an electronic go/no-go poll for propellant loading. If the “go” is given, launch control starts the auto sequence, allowing propellant loading to begin. The first and second stages begin RP-1 loading, while LOX loading simultaneously starts on the first stage.

Thirteen minutes later, stage two RP-1 loading is complete with a purge of the T/E at T-20 minutes. At T-16 minutes, LOX loading begins on stage two. At T-7 minutes, the Falcon 9 first stage chills its engines with liquid oxygen to ensure there are no thermal shocks to the engines at ignition. The T/E retracts to the launch position at T-4 minutes 30 seconds.

Propellant loading is complete at T-2 minutes. Two significant events occur simultaneously a minute later: the flight computer enters “startup,” and the propellant tanks pressurize to flight levels. The launch director gives the final “go” for launch 45 seconds before liftoff.

At T-3 seconds, the engine controller commands the nine first-stage Merlin 1D engines to ignite. A second later, the engines ignite and begin a final health check. Once the engines are verified healthy and producing full thrust, the hydraulic hold-down clamps and the T/E retract, allowing the vehicle to liftoff.

Shortly after liftoff, Falcon 9 pitches to follow the proper flight path to reach an 87.4-degree orbit. Initially, Falcon 9 will pitch south-southeast and then complete a “dogleg” maneuver to the south to reach the proper azimuth for the desired orbit. The dogleg maneuver is needed to avoid overflight of populated areas on the Florida coast south of the space center.

After one minute and 12 seconds of flight, Falcon 9 reaches maximum aerodynamic pressure (Max-Q).

After burning for two minutes and 17 seconds, the nine first-stage engines shut down. A few seconds later, the two stages separate. Second Engine Start (SES)-1 begins just after stage separation. At the same time, the first stage begins a flip maneuver to head back to LZ-1. After a near 180-degree rotation, the first stage will ignite engines one, five, and nine for a 48-second burn back to LZ-1.

After completing the boostback burn, the four titanium grid fins deploy. Six minutes and four seconds into the flight, the same three engines reignite for the entry burn, which lasts 17 seconds. The entry burn helps protect the stage from the forces caused by reentering Earth’s atmosphere.

Once the entry burn is complete, the first stage will descend before reigniting engine nine one last time for the landing burn. The nearly 30-second burn will allow for a gentle landing on LZ-1; if successful, B1069-4 will then be redesignated B1069-5. After landing, SpaceX will move B1069 off of LZ-1 to refurbish the booster for a future mission.

While B1069 returns to LZ-1, the second stage continues to orbit. The payload fairing separates just over three minutes into the flight, exposing the 40 OneWeb satellites to space. The fairings will be recovered ~604 km downrange by Doug.

Stage two will burn until reaching an initial low Earth parking orbit. The second stage will coast to apogee for a short and final four-second burn. In this final orbit, the OneWeb satellites will separate from the payload adaptor over just more than 30 minutes. Once the satellites are in orbit, it will raise the number of OneWeb satellites to 494 of its 648 initial target.

OneWeb is a global communication provider with the second-largest satellite constellation. The company began launching its satellites in February 2019. Since then, the company has seen most launches from Soyuz and a singular GSLV Mk. III launch.

In February 2019, Arianespace launched the first six satellites on a Soyuz ST-B/Fregat-M from the Guiana Space Center. The first six satellites were test satellites built by the OneWeb/Airbus joint venture Airbus OneWeb Satellites.

OneWeb selected Airbus to build the satellites in 2015.

Airbus built the first set of satellites at their factory in France before the satellites’ primary production moved to Florida. OneWeb satellites are small, ~148 kg, and use electric propulsion to raise and keep their 1,200 km orbits. Twin solar panels power the spacecraft and its Ku-band antennas. With 40 satellites on Launch #15 – the most OneWeb satellites launched at once – the total mass on Falcon 9 is ~6,000 kg.

More exciting news ahead of launch as we confirm the successful encapsulation of all 40 satellites.

Huge thanks goes to our colleagues on site for reaching this milestone.

You can find more information on Launch #15 on our website at:https://t.co/YpHxj4H4Iy#OneWebLaunch15 pic.twitter.com/k3vwFsP2a5

— OneWeb (@OneWeb) December 2, 2022

The first operational launch with 34 satellites took place a year after OneWeb Launch #1, on Feb. 6, 2020. OneWeb and Arianespace completed 12 more launches until Feb. 10, 2022, when the final launch with a Soyuz took place.

Launches on Soyuz halted and were abandoned shortly after the Russian invasion of Ukraine, when, shortly after, OneWeb signed launch contracts with SpaceX and India to launch its remaining satellites.

India launched the first of its two missions in October 2022 with 36 satellites. SpaceX will launch three missions, with its next scheduled for January 2023. Following Launch #15, OneWeb will have three more total launches before its initial constellation is complete.

SpaceX still has multiple missions planned in 2022 as it attempts to reach its 60-launch goal. After OneWeb Launch #15 is the HAKUTO-R mission on Dec. 11 at 2:38 AM EST (07:38 UTC). Next is the SES O3b mPOWER 1 & 2 satellites from SLC-40, currently set for mid-December.

Around the same time, SpaceX will launch NASA/CNES SWOT mission from Vandenberg as the first global survey of Earth’s surface water. Finally, at a similar time, SpaceX will launch Transporter-6, another mission using the polar corridor from Florida.

To fill in any gaps in the month, SpaceX will launch Starlink missions, with at least one before the end of the year. Before the end of the month, SpaceX will launch the EROS-C3 Earth observation satellite for Israel.

(Lead Image: Falcon 9 on LC-39A ahead of the Starlink v1.0 L6 launch in April 2020. Credit: Julia Bergeron for NSF)

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