SpaceX // February 18, 2023

Inmarsat-6 F2

Launch Overview

Lift of Time:

Launch Window:

Launch Pad:

Launch Facility:

February 18, 2023 - 03:59:00 (+00:00)

03:59:00 - 05:28:00

Space Launch Complex 40

Cape Canaveral

Mission Details

Inmarsat-6 is the sixth generation of satellites for the London-based global mobile satellite communications operator Inmarsat. It consists of a dual mission to augment both L-band and Ka-band Global Xpress services. Airbus Defence and Space has been awarded a contract by Inmarsat to design and develop the first two Inmarsat-6 (I-6) mobile communications satellites, creating the most versatile mobile services satellites in its fleet. The two I-6 satellites are based on Airbus Defence and Space's Eurostar platform in its E3000e variant, which exclusively uses electric propulsion for orbit raising. The satellites take advantage of the reduction in mass that this electric propulsion technology enables for a dual payload mission, with an exceptionally large next generation digitally processed payload. I-6 F1 and F2 both carry a large 9 m aperture L-band antenna and nine multibeam Ka-band antennas, and feature a high level of flexibility and connectivity. A new generation modular digital processor provides full routing flexibility over up to 8000 channels and dynamic power allocation to over 200 spot beams in L-band. Ka-band spot beams are steerable over the full Earth disk, with flexible channel to beam allocation.

Recovery Overview

Landing Location:

Landing Type:

Just Read the Instructions (JRTI)

Autonomous Spaceport Drone Ship

Watch Replay

Who is SpaceX?

Space Exploration Technologies Corp., better known as SpaceX is an American aerospace company providing cheap and reliable launch services as well as ferrying crew and cargo to and from the International Space Station as part of NASA’s Commercial Crew and Commercial Resupply Services program.

What Is Falcon 9 Block 5?

Falcon 9 is a two-stage rocket designed and manufactured by SpaceX for the reliable and safe transport of satellites and the Dragon spacecraft into orbit. The Block 5 variant is the fifth major interval aimed at improving upon the ability for rapid reusability.


Merlin 1D (stage 1)

The Merlin engine is a rocket engine developed by SpaceX that uses a combination of rocket-grade kerosene and liquid oxygen as fuel. It is designed to provide high thrust and reliability for use in the company's Falcon 9 and Falcon Heavy rockets.

The Merlin 1D engine represents a significant improvement over its predecessor, Merlin 1C. It features a number of enhancements that make it more powerful, reliable, and efficient. The engine produces 190,000 pounds of thrust at sea level and 210,000 pounds of thrust in vacuum, which is more than 50% greater than the Merlin 1C engine.

The improved performance of the Merlin 1D engine is due to a number of factors. It has a higher chamber pressure, which allows for more efficient combustion and higher thrust. It also has an expanded nozzle, which allows for better expansion of exhaust gasses and higher thrust in vacuum. In addition, the engine features a more advanced turbopump that can deliver more fuel and oxidiser to the combustion chamber at a faster rate.


SpaceX began development of Merlin 1D between 2011 and 2012. The design goals for Merlin 1D were increased reliability, improved performance and improved manufacturability. Of which all primary design goals were met, if not exceeded.

First Flight

CASSIOPE launch | Credit: SpaceX

SpaceX's first launch of the newly improved Merlin 1D engine was during the maiden flight of Falcon 9 v1.1 with the CASSIOPE mission on September 19th, 2013 from SLC-4E at Vandenberg Space Force Base (then Air Force Base).

The flight was a complete success with the CASSIOPE being deployed in its target orbit.


Merlin 1D static fire test | Credit: SpaceX

SpaceX tests every Merlin before it is fitted to a Falcon 9 or Falcon Heavy rocket. This is done at the company’s facility in McGregor, TX. Each Merlin undergoes a static fire test, typically lasting 142 seconds (slightly below the full duration of a Falcon 9 first stage burn). SpaceX tests many Merlin engines each week to keep up with the ever growing launch demand for Falcon 9 and Falcon Heavy.

SpaceX’s rigorous testing of Merlin, especially during early development, played a large role in the reliability of the engine and the rockets it powers.


Falcon 9 returns to Earth after successful flight | Credit: SpaceX

Reusability was a major factor during development of Merlin 1D. The engine is capable of multiple restarts, making it suitable for multiple missions. In addition, SpaceX recovers their first stage of their Falcon 9 and Falcon Heavy rockets where possible. This involves landing the first stage on a landing pad or drone ship after it separates from the second stage. 

By reusing the first stage and the engines, SpaceX can reduce the cost of each launch and make access to space more ‘affordable’. 

While reusability is a driving force to lowering costs, it also plays a factor in the incredible reliability of the Falcon family. When reused, Falcon first stages gain flight heritage which reduces risk of component failure.

The Gas Generator Cycle

The gas generator cycle, sometimes referred to as the "open cycle", taps off a small amount of fuel (in the case of Merlin, this is RP-1) and oxidiser (LOX in the case of Merlin) from the main flow to feed a burner called a "gas generator". Once the fuel and oxidiser pass through the gas generator and is changed from it's cold, liquid state to a hot gas, it passes through a turbine to produce power which drives pumps which then sends the propellants through the combustion chamber and out of the nozzle.

Merlin 1D Vacuum (stage 2)

Merlin 1D Vacuum is a vacuum optimised version of SpaceX's Merlin 1D engine used on the Falcon 9 and Falcon Heavy second stages.

Rocket Overview



Falcon 9 Block 5



LC-39A October 05, 2022
104 days
SLC-40 January 18, 2023
30 days
SLC-40 February 18, 2023
Inmarsat-6 F2

Space Launch Complex 40

Cape Canaveral, FL, USA

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