Subj : SpaceX to launch OneWeb 17 mission and return booster to LZ-1 To : All From : NasaSpaceFlight Date : Thu Mar 09 2023 16:00:03 SpaceX to launch OneWeb 17 mission and return booster to LZ-1 Date: Thu, 09 Mar 2023 15:59:09 +0000 Description: SpaceX is set to launch 40 high-speed internet communication satellites to a polar low Earth The post SpaceX to launch OneWeb 17 mission and return booster to LZ-1 appeared first on NASASpaceFlight.com . FULL STORY ====================================================================== SpaceX is set to launch 40 high-speed internet communication satellites to a polar low Earth orbit on the OneWeb 17 mission on Thursday. Launching from Space Launch Complex 40 (SLC-40) at the Cape Canaveral Space Force Station in Florida, the Falcon 9 is scheduled to lift off at 2:13 PM EST (19:13 UTC) and will mark SpaceXs 16th orbital launch of 2023a launch every 4.25 days. Following the launch, just under 90% (578 of the planned 648) of operational satellites will have been launched. The satellites will be placed into a ~580 by 600 km orbit, inclined at 86.51 degrees. The satellites will then spend the coming months raising their orbits to the operational 1,200 km circular polar orbit at 86.4 degrees. See Also OneWeb 17 L2 SpaceX Section Click here to Join L2 NSF Store On March 7, Space Launch Delta 45 released a launch mission execution forecast giving the weather a 5% chance of violating the weather constraints. The only concern is the cumulus cloud rule. In the event of a delay, a backup launch opportunity exists 24 hours later, with the probability of violating weather constraints increasing to 15%. The Falcon 9 booster supporting this mission is B1062-13; as the name implies, the booster has supported 12 previous missions: seven Starlink missions, two GPS missions, Inspiration4, Axiom-1, and Nilesat-301. Following the launch, the stage will perform a return to launch site (RTLS) landing , landing on SpaceXs Landing Zone 1 (LZ-1). If successful, this will be SpaceXs fifth RTLS landing this year, 177th booster landing, 103rd consecutive successful landing, and 27th landing on LZ-1. Once jettisoned from the second stage, the payload fairings will softly splash down in the ocean under a parachute. SpaceXs multi-purpose recovery vessel Bob will then recover them from the water. SpaceX recovery ship Bob has departed Port Canaveral and is heading south down the polar corridor to position itself to recover the fairing for the upcoming OneWeb #17 mission. The booster will RTLS to LZ-1, CCSFS. pic.twitter.com/n7hygJqguT Gav Cornwell (@SpaceOffshore) March 7, 2023 OneWebs constellation is a satellite internet constellation with the goal of providing internet coverage to the entire globe. Once complete, the constellation will be made up of 36 satellites in each of the 18 orbital planes. 600 of these satellites are needed for global coverage, with an additional 48 on-orbit spares. Based on demand, the constellation could later be expanded to more than 900 satellites. Each OneWeb satellite has a compact design and masses ~150 kg. They are equipped with a Ku-band antenna, which operates between 12 and 18 GHz, allowing for each satellite to have 8 gigabits per second of throughput. Initially, the satellites had a Russian Fakel SPT-50 ion thruster; however, due to the conflict in Ukraine, this was changed to the Busek BHT-350 Hall effect thrusters on the newer satellites. The satellites have two solar panels for power and are built by Airbus Defence and Space; the first 10 were built in Toulouse, France, and the remainder have been made in OneWebs US-based factory. Originally, OneWebs satellites were being launched by Arianespace and Roscosmos atop the Soyuz-2.1b/Fregat-M. In 2022, also due to the conflict in Ukraine, OneWeb moved these launches over to SpaceXs Falcon 9 and ISROs GSLV Mk. III. OneWeb satellites being prepared for integration ahead of the next ISRO OneWeb launch. (Credit: OneWeb) The now routine Falcon 9 launch sequence starts at T-38 minutes, where the launch director will verify that all systems are go for propellant load. Fueling of both the first and second stages starts at T-35 minutes, alongside first stage liquid oxygen (LOX) load. The Falcon 9 utilizes super-chilled LOX and sub-cooled rocket propellant-1 (RP-1). This increases the density of the propellants, increasing the amount that can be stored on the vehicle and the Merlin engines performance. At T-20 minutes, fueling of the second stage will be complete and the transporter erector will begin purging its lines, preparing the lines for stage two LOX load, which starts at T-16 minutes. This purging is what creates the Falcon 9s classic T-20-minute vent and is done to thermally condition and clean the lines ahead of LOX load. At T-1 minute, Falcon 9 will enter start-up and the tanks will begin to pressurize to flight pressures. 15 seconds later, the launch director will verify that the vehicle is go for launch. At T-3 seconds, the engine controller will command engine ignition of all nine Merlin 1D engines on the first stage. This is done by flowing trimethylaluminum and triethyl-borane (TEA-TEB) through the engines. TEA-TEB is pyrophoric, meaning it ignites when in contact with oxygen. Falcon 9s nine Merlin 1D engines shortly after liftoff. (Credit: SpaceX) Just before launch, the flight computer will verify that all nine engines and the vehicle are operating nominally and will command the launch clamps to release the vehicle. The first stage will burn for 137 seconds before shutting down and the stages separate. At this point, the second stages single Merlin vacuum engine will ignite, and the first stage will begin a flip and will ignite three engines for its boostback burn, which will last 48 seconds. Three and a half minutes into the flight, the second stage will jettison the fairings. The first stage will perform two more burns (the reentry and landing burns), before softly touching down on LZ-1 just under eight minutes after launch. Upon successful landing, the boosters designation will change to B1062-14. Second stage engine cutoff 1 (SECO-1) will occur at T+8:34 before the stage enters into a ~47-minute long coast phase. The second stage will then perform a three-second long burn, with SECO-2 occurring at T+55:20, before starting to deploy OneWeb satellites two at a time at T+58:50. This process will last a little under 37 minutes, with all satellites being deployed by T+1:35:18. This launch will mark SpaceXs third launch of March, with CRS-27, SES-18 & SES-19, and Starlink missions scheduled for later in the month. (Lead image: B1062 at SLC-40 ahead of the Nilesat-301 mission in June 2022. Credit: Stephen Marr for NSF) The post SpaceX to launch OneWeb 17 mission and return booster to LZ-1 appeared first on NASASpaceFlight.com . ====================================================================== Link to news story: https://www.nasaspaceflight.com/2023/03/oneweb-17/ --- Mystic BBS v1.12 A47 (Linux/64) * Origin: tqwNet Science News (1337:1/100) .