SES-18 & SES-19 | Falcon 9 Block 5

Featured image credit: SpaceX
Lift Off Time
(Subject to change)

March 17, 2023 – 23:34 UTC | 19:34 EDT

Mission Name

SES-18 & SES-19

Launch Provider
(What rocket company is launching it?)


(Who’s paying for this?)



Falcon 9 Block 5

Launch Location

Space Launch Complex 40 (SLC-40), Cape Canaveral Space Force Station, Florida, USA

Payload mass

~7,000 kg (15,400 lb)

Where is the satellite going?

Geostationary Transfer Orbit (GTO)

Will they be attempting to recover the first stage?


Where will the first stage land?


Will they be attempting to recover the fairings?


Are these fairings new?


How’s the weather looking?

The weather is currently 70% go for launch (as of March 14, 2023)

This will be the:

– 212th Falcon 9 launch
– 117th SpaceX launch from SLC-40
– 19th launch for SpaceX in 2023

 42nd orbital launch attempt of 2023

Where to watch

Once available, an official livestream will be listed here

What Does All This Mean?

SpaceX will launch the SES-18 & SES-19, two C-band satellites, to a Geostationary Transfer Orbit (GTO) on their Falcon 9 Block 5. The rocket will lift off from Space Launch Complex 40 at the Cape Canaveral Space Force Station in Florida, marking the 18th launch of the company this year.

A logo of the SES satellites. (Credit: SES)

SES-18 & SES-19 Mission

The SES-18 & SES-19 are C-band communication satellites owned by SES S.A., a Luxembourgian telecommunication company. The satellites were designed, produced, and tested by Northrop Grumman in Dulles, Virginia. Each satellite has a mass of 3,500 kg, two solar arrays, a lifespan of 15 years, and is equipped with a high-quality C-band payload. Their main aim is to provide North America with digital broadcasting services. Together with the other four satellites (SES-20, SES-21, SES-22, and SES-23), the SES-18 & SES-19 satellites will contribute to the effort of clearing the lower portion of the C-band spectrum necessary to deploy 5G services in the United States.

The SES-18 and SES-19 satellites. (Credit: Advanced Television)

The SES-18 & SES-19 likely make use of a software system called Adaptive Resource Control (ARC). This software already supports the SES-17 satellite launched in October 2021. ARC provides dynamic management of service requests and available resources in orbit and on the ground. SES has been working on ARC with Kythera Space Solutions since September 2019, when they jointly announced the development.

The satellites Northrop Grumman’s facility. (Credit: Northrop Grumman via Twitter)

The satellites use a GEOStar-3 satellite platform developed by Northrop Grumman. Compared to the previous generation (GEOStar-2), this platform has better battery capacity and increased solar array power. Some characteristics of the GEOStar-3 bus can be found here.

What Is Falcon 9 Block 5?

The Falcon 9 Block 5 is SpaceX’s partially reusable two-stage medium-lift launch vehicle. The vehicle consists of a reusable first stage, an expendable second stage, and, when in payload configuration, a pair of reusable fairing halves.

First Stage

The Falcon 9 first stage contains 9 Merlin 1D+ sea-level engines. Each engine uses an open gas generator cycle and runs on RP-1 and liquid oxygen (LOx). Each engine produces 845 kN of thrust at sea level, with a specific impulse (ISP) of 285 seconds, and 934 kN in a vacuum with an ISP of 313 seconds. Due to the powerful nature of the engine, and the large amount of them, the Falcon 9 first stage is able to lose an engine right off the pad, or up to two later in the flight, and be able to successfully place the payload into orbit.

The Merlin engines are ignited by triethylaluminum and triethylborane (TEA-TEB), which instantly burst into flames when mixed in the presence of oxygen. During static fire and launch, the TEA-TEB is provided by the ground service equipment. However, as Falcon 9 first stage is able to propulsively land, three of the Merlin engines (E1, E5, and E9) contain TEA-TEB canisters to relight for the boost back, reentry, and landing burns.

Second Stage

The Falcon 9 second stage is the only expendable part of the Falcon 9. It contains a singular MVacD engine that produces 992 kN of thrust and an ISP of 348 seconds. The second stage is capable of doing several burns, allowing the Falcon 9 to put payloads in several different orbits.

For missions with many burns and/or long coasts between burns, the second stage is able to be equipped with a mission extension package. When the second stage has this package, it has a grey strip, which helps keep the RP-1 warm, an increased number of composite-overwrapped pressure vessels (COPVs) for pressurization control, and additional TEA-TEB.

Falcon 9 Block 5 launching on the Starlink V1.0 L27 mission (Credit: SpaceX)

Falcon 9 Fairings

The Falcon 9’s fairing consists of two dissimilar reusable halves. The first half (the half that faces away from the transport erector) is called the active half and houses the pneumatics for the separation system. The other fairing half is called the passive half. As the name implies, this half plays a purely passive role in the fairing separation process, as it relies on the pneumatics from the active half.

Both fairing halves are equipped with cold gas thrusters and a parafoil which are used to softly touch down the fairing half in the ocean. SpaceX used to attempt to catch the fairing halves; however, at the end of 2020, this program was canceled due to safety risks and a low success rate.

In 2021, SpaceX started flying a new version of the Falcon 9 fairing. The new “upgraded” version has vents only at the top of each fairing half, by the gap between the halves, whereas the old version had vents placed spread equidistantly around the base of the fairing. Moving the vents decreases the chance of water getting into the fairing, making the chance of a successful scoop significantly higher.

An active Falcon 9 fairing half (Credit: Greg Scott)

Falcon 9 passive fairing half (Credit: Greg Scott)

Half of the fairing being taken off Go. Navigator. (Credit: Lupi)

A passive fairing half being unloaded from Shelia Bordelon after the Starlink V1.0 L22 mission (Credit: Kyle M)

SES-18 & SES-19 Countdown

All times are approximate and are based on the SES-22 mission.

HR/MIN/SECEVENT00:38:00SpaceX Launch Director verifies go for propellant load00:35:00RP-1 (rocket grade kerosene) loading underway00:35:001st stage LOx (liquid oxygen) loading underway00:16:002nd stage LOx loading underway00:07:00Falcon 9 begins engine chill prior to launch00:01:00Command flight computer to begin final prelaunch checks00:01:00Propellant tank pressurization to flight pressure begins00:00:45SpaceX Launch Director verifies go for launch00:00:03Engine controller commands engine ignition sequence to start00:00:00Falcon 9 liftoff

SES-18 & SES-19 Launch and Landing

All times are approximate

HR/MIN/SECEVENT00:01:12Max Q (moment of peak mechanical stress on the rocket)00:02:301st stage main engine cutoff (MECO)00:02:331st and 2nd stages seperate00:02:412nd stage engine starts (SES-1)00:03:24Fairing deployment00:06:161st stage entry burn begins00:06:421st stage entry burn complete00:08:022nd stage engine cutoff (SECO)00:08:071st stage landing burn begins00:08:341st stage landing00:27:082nd stage engine restarts (SES-2)00:28:152nd stage engine cutoff (SECO-2)00:33:26SES-18 & SES-19 deploys

The post SES-18 & SES-19 | Falcon 9 Block 5 appeared first on Everyday Astronaut.

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