SpaceX Falcon 9 Block 5 - AMOS-17 - Launching August 6/7, 2019
Screenshot from Tim Dodd: SpaceX launch of a Falcon 9 with AMOS-17
Mission Rundown: SpaceX Falcon 9 B5 - AMOS-17
Written: January 5, 2021
Screenshot from Tim Dodd: SpaceX mission view of AMOS-17 by Geoff Barrett
Let’s go where everybody knows your name
SpaceX will be launching the AMOS-17 satellite for Spacecom on a Falcon 9 rocket. The Falcon 9 will be lifting off from Space Launch Complex 40 (SLC-40) at the Cape Canaveral Air Force Station (CCAFS) in Florida.
This booster, B1047-3, is flying for the third and last time. It previously boosted the Telstar 19 VANTAGE and Es’hail-2 satellites to orbit. The booster will not be recovered and will be expended on this mission.
GO Ms. Tree (formerly known as Mr. Steven) and GO Navigator left Port Canaveral, indicating a recovery of the fairings is going to be attempted.
The Payload
Amos-17 is an Israeli commercial communication satellite, part of the AMOS series of satellites. It was launched on August 6, 2019, and is a Boeing type 702MP satellite transmitting in the Ka, Ku, and C bands. It is a replacement for Amos-5 and provides coverage over the continent of Africa, as well as Europe and the Middle East. The satellite was reportedly aimed to be located at 17° East longitude but, in November 2019, it was at 14° East where it has been since August 19.
The Satellite later recovered its Destination to 17o East again.
AMOS-6 was intended to be launched on Flight 29 of a SpaceX Falcon 9 to geostationary transfer orbit (GTO) on 3 September 2016. On 1 September 2016, during the run-up to a static fire test, there was an anomaly on the launch pad, resulting in an explosion and the loss of the vehicle and AMOS-6. There were no injuries.
The explosion started near the upper stage LOX (liquid oxygen) tank. Because the satellite was destroyed prior to the launch, the cost of the satellite was not covered by Spacecom's insurance policy, but rather by the manufacturer, IAI.
IAI had its own insurance and filed a claim in order to compensate Spacecom. Spacecom's contract with SpaceX specified that Spacecom could choose to receive US$50 million, or a future flight at no cost. Spacecom chose the future flight to launch AMOS-17.
The Fairings
The picture below contains a few details about the fairing recovery control systems, there are 3 tanks with cold nitrogen gas, 3 gas thrusters at the nose tip, a silver foil to protect a parachute and a number of black avionics computer or control boxes. The rest is sound and shock absorbent material cotton, which are there to protect the payload during ascent passing through supersonic and Max Q. It’s a hard material to clean and dry.
At the bottom you can just make out a Drogue Parachute Mortar, which blasts a small high velocity Drogue Parachute out past the turbulence caused by the large fairing, as it descends through the atmosphere. It will later pull out the main steerable parachute, which will softly land the fairing either in the GO Ms. Tree’s net or on the ocean surface.
The Fairing is built like a boat hull of woven glass fiber and carbon fiber cast in vacuum packed resin. The inside is lined with aluminum honeycomb plates that together with sound and shock absorbent cotton materials protects the satellite. The fairing pair has a male side with spring loaded pusher rods that push away the “female” lighter side some 30 seconds after Second Engine Start - SES-1 when reaching empty space.
There have been a number of iterations of fairing types built. Type 1 was carbon fiber and aluminum honeycomb fairings, Type 2 had an extra layer of carbon fiber and aluminum honeycomb on fairings, and then with a metal net reinforcement to make it even stronger, so it would survive the impact with the tall waves.
Cameras installed in the fairings revealed the flight profile, they were probably stalling and gliding like dry leaves, so the Attitude Control System - ACS nitrogen thrusters, flight avionics computers, parachutes and other things were installed.
Type 2.1: The tip of the fairings have also been reinforced with steel plates. During ascent the fairing tip moves a lot of air aside, so it gets glowing red hot. Also most likely make it nose heavy to change the glide profile during reentry in the atmosphere, so it wouldn’t stall so easily and put a lesser toll on the ACS thrusters during reentry.
AMOS-17 is getting ready to be launched by SpaceX. Screenshot.
But another last change, Type 3 - was needed, when salt water got in through the bottom decompression vents, which let the nitrogen gasses out of the fairing during ascent.
The ventilation ports sit in a circular line evenly spaced row near the bottom quarter of the fairings, so when floating on water ventilation ports 2 and 3 were below the waterline, and the fairing halfs slowly flooded with salt water.
The solution to this problem was moving ventilation ports 2 and 3 to port 1 and 4 that are placed closer to the fairing edges. Some Type 2 were rebuilt as Type 3.1 and mainly reused on Starlink launches, as these didn't need to look pretty, only light enough.
Most fairings have landed on the ocean like this. They are just like boats, and depending on the waves on landing they will be recoverable just like this one from the launch of Iridium 5 NEXT flight out of Vandenberg Air Force Station.
Type 1 fairing test landed safely according to Elon Musk tweet of 22 february 2018.
I wonder if a long robe or line from the tip of the fairing would make it easier to catch it like a kite. You just pull it into the boat, and let it land softly on the boat deck. Yes.
