SpaceX successfully launched two new C-band communication satellites

On March 17, 2023, at 07:38 p.m. EDT (23:38 UTC) a SpaceX Falcon 9 block 5 rocket lifted off from Launch Complex 40 (SLC-40) at Cape Canaveral Space Force Station, in Florida USA, carrying the SES-18 & SES-19 mission for a 7,000 kg (15,400 lb) total payload mass. This is the 19th successful launch for SpaceX in 2023.

📰 You heard it here first! Our #SES18 & #SES19 satellites have successfully launched into space! 🚀🛰️🛰️

Developed by @northropgrumman & launched by @SpaceX, this marks the final launch milestone in our C-band transition plan.

Read the #SESNews 👉 https://t.co/z5rzSkISTN pic.twitter.com/cwFJh976sA

— SES (@SES_Satellites) March 18, 2023

After stage separation, the first stage booster conducted two reentry burns and landed back on the drone ship Just Read the Instructions in the Atlantic Ocean. The B1069 Booster that supported this mission completed its sixth flight overall.

32 and 37 minutes after liftoff the second stage deployed the SES-18 and SES-19 satellites into a “sub-synchronous” transfer orbit. The two spacecraft will finally reach and operate at an altitude of 22,000 miles (35,400 kilometers) in geostationary orbit.

This mission carried two new C-band satellites operated by the Luxembourgish satellite telecommunications network provider SES S.A., a historic customer for SpaceX. The production of the spacecraft was awarded to Northrop Grumman Corporation in June 2022.

SES-18 and SES-19 satellites

SES-18 and SES-19 are the latest two aircraft of the SES’s C-band communications satellites fleet launched in only nine months. SES-22 was built by Alenia Space and launched by SpaceX in June 2022. SES-20 and SES-21 instead were built by Boeing and launched on a United Space Alliance (ULA) Atlas V rocket in October. SES-23 is a ground spare under construction, to prevent the risk of a potential failure affecting the last two vehicles.

The two new satellites’ design is based on Northrop Grumman’s GEOStar-3 satellite platform, which compared to the previous version (GEOStar-2) has better battery capacity and an increased solar array power.

This rapid succession of new SES communication satellites is given by the decision of the Federal Communications Commission (FCC) to clear the C-band spectrum across the US, in order to make space for the 5G services in the near future. The new satellites will transition the C-band services from the lower 300 MHz to the upper 200M Hz of the spectrum, providing TV, radio and data relay services for more than 15 years.

Falcon 9 reliability

Thanks to this mission SpaceX set a new record for the shortest turnaround time between two Falcon 9 launches. On Friday 18, at 03:26 p.m. EDT (19:26 UTC) a Falcon 9 lifted off from Vandenberg Space Force Base in California, carrying 52 new Starlinks satellites. Between the two launches, only 4 hours have passed!

This launch rate is possible thanks to the reliability of SpaceX’s Falcon 9 rocket.

Falcon 9 is a two-stage partially reusable rocket designed and manufactured by SpaceX. The unique capacity of reflight has a major impact on cost reduction and the sector’s sustainability. SpaceX has completed 211 Falcon 9 total launches and 146 reflights so far.

The first stage is powered by 9 Merlin engines that produce 845 kN of thrust each at sea level. The second stage is the only expendable part of the Falcon 9 and is powered by a single Merlin Vacuum Engine that produces 981 kN of thrust.

After separation, the first stage booster performs two reentry burns to decelerate and is able to land both on the mainland or on a drone ship at sea.