Screenshot of SpaceX Webcast of the Galaxy 31-32 launch. I’m naked. No grid fins or landing legs
Mission Rundown: SpaceX Falcon 9 - Galaxy 31-32
Written: November 12, 2022
That’s it for me. I’m clocking out
SpaceX is set to launch two communication satellites to geostationary transfer orbit (GTO) for Intelsat. The Galaxy 31 & 32 satellites will be launched from SpaceX’s Space Launch Complex 40, at the Cape Canaveral Space Force Station, in Florida, USA.
Following deployment from the second stage, the satellites will spend the coming months raising their orbits to their operational orbit in geostationary Earth orbit (GEO). Galaxy 31 & 32 is expected to be operational by January 2023.
It will launch Saturday, November 12, 2022 at 11:06 EST, from SLC-40. Galaxy 31 & 32 first stage booster B1051-14 will deliberately be expended to give its payload Galaxy 31 & 32 a maximum of delta v before stage separation.
After boosting the second stage along with its payload towards orbit, the first stage will freefall in a parabolic curve before it crashes into the Atlantic Ocean. Only a few of the old Falcon 9 first stage boosters will be kept in operational rotation to determine the durability of the Falcon 9 Block 5 booster design. 20 flights is the maximum I’m guessing.
SpaceX will also recover both fairing halves in the Atlantic Ocean with the recovery vessel Bob, named after Demo-2 Astronaut Bob Behnken.
B1051-14 will make its fourteenth and last flight after launching the next mission:
B1051-14 didn’t perform a static fire test after refurbishment while waiting for an east coast launch out of Cape Canaveral. SpaceX has since Starlink L08 omitted this safety precaution many times so far. It isn’t required to perform a static fire test on inhouse missions like Starlink as to save time.
SpaceX is the first entity ever that recovers and reflies its fairings. After being jettisoned, the two fairing halves will use cold gas thrusters to orientate themselves as they descend through the atmosphere. Once at a lower altitude, they will deploy drogue chutes and later a parafoil to help them glide down to a soft landing for recovery.
Falcon fairings halfs have been recovered and reused since 2019. Improved design changes and overall refurbishment procedures have decreased the effects of water landings and led to an increased recovery rate of fairings.
The fairings are a used pair each from five previous missions with no known joint mission. Both fairings are expected to survive the landing. Active fairings are equipped with four pushrods to separate the two fairing halfs.
Fairings have evenly spaced venting ports that have been redesigned a number of times by having first ten, then eight and now having their venting ports built as close pairs along the fairing edge. This prevents saltwater from the ocean from flooding and sinking the fairing, and makes refurbishment toward the next flight easier.
The Intelsat Payload
The Galaxy 31 & 32 satellites are replacements for Intelsat’s aging satellites in 133º and 129º GEO slots, respectively. Each of these satellites are C-band-only communication satellites, allowing the satellites to service North America with television broadcasting.
These two satellites are thought to be based on the 200 kilo lighter Maxar 1300 satellite Bus and are equipped with the IHI BT-4 propulsion module. Built by the Japanese company IHI aerospace, the BT-4 is a pressure-fed engine that runs on N2O4 and Hydrazine. It produces 500 N of thrust in a vacuum with an ISP of ~320 seconds.
This engine is also used on Cygnus and HTV — which are two ISS resupply vehicles.
These satellites are a part of Intelsat order of six new satellites: four of which will be built by Maxar Technologies and two which will be built by Northrop Grumman. If all of these satellites are operational by December 5, 2023, Intelsat will receive $4.87 billion from the Federal Communication Commission (FCC) in the FCC’s attempts to clear the 300 MHz spectrum, which is used in cellular 5G networks.
The satellites have an expected lifespan of 15 years, and they are powered by two deployable solar arrays and batteries. While neither Intelsat or Maxar have released the mass of the satellite, it is expected that the satellite masses roughly 3,500 kg based on previous satellites and the Falcon 9’s performance.
Galaxy satellite during testing - Reflector is deployed - Humans for scale - Credit: Intelsat source
No comments:
Post a Comment