Falcon 9: Inmarsat-5 4F (KSC mission)


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Good stuff, great launch and deploy. Another notch in the belt for SpaceX, and Inmarsat gets their redundancy for their constellation. :yes: 

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11 hours ago, Unobscured Vision said:

You wouldn't think it was a heavy bird ... nicely done. That S1 was pushing it with power to spare. :D:yes: 

Some person on reddit is claiming the first stage was Block 3 and second stage Block 4... Any thoughts?

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I'll direct you to this post:

Spurred on from this tweet:

More information will be forthcoming. Till then nothing can be said. Gotta be careful how this is handled. Think back to the previous launch, the NROL one. Those rules are still in effect for the time being. There's a good reason (several, in fact), but for right now mum's the word. :) 

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Sorry if it's already been discussed and I've missed it but why no stage one landing this time? I'm assuming it's to do with the weight of the satellite that was being lifted? If so is that something they will fix with future revisions?

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6 minutes ago, Skiver said:

Sorry if it's already been discussed and I've missed it but why no stage one landing this time? I'm assuming it's to do with the weight of the satellite that was being lifted? If so is that something they will fix with future revisions?

Heavy satellite, so not enough fuel left over to do a landing this time. And yes, Block 5's will have enough grunt to haul heavy sats like these into GTO and then land on the droneship. This one was actually supposed to fly on Falcon Heavy.

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3 minutes ago, Unobscured Vision said:

Heavy satellite, so not enough fuel left over to do a landing this time. And yes, Block 5's will have enough grunt to haul heavy sats like these into GTO and then land on the droneship. This one was actually supposed to fly on Falcon Heavy.

 

I don't follow or understand most of this stuff to the level you guys do but I find it fascinating so thanks.

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Confirmation this was a super-synchronous insertion, which means the apogee was above a geostationary orbits altitude, 35,786 km, and the perigee below it.

 

The satellite then circularizes the orbit using it's own propulsion, which can be either chemical thrusters (faster, days, but heavy) or ion thrusters (slower, months, but very light.) It's a trade.

 

Falcon 9 has tossed a lighter satellite, Thaicom-8 at 3,025 kg, to a 90,000 km super-synchronous apogee and the stage still managed to land on ASDS, but Inmarsat-5 F4 was too heavy for this at 6,070 kg. Still, Falcon 9 managed to throw this big bird to 70,181km x 384km with a 24.47° inclination. Wow!

 

And as everyone witnessed, this Falcon 9 literally jumped off the pad even with 6,070 kg in the fairing, so there's no doubt there was a significant first stage performance upgrade. This may be why an Inmarsat staffer called it a "Falcon 9 Super Sport" in a tweet. Indeed :)

 

The upper stage was also different, as was the one used on NROL-76. Several exterior features have changed, and the NROL-76 upper stage did an acknowledged long duration cruise test before reigniting its engine - a DoD requirement.

 

Something tells me the Falcon 9/Falcon Heavy capabilities page will get another performance number update.

 

 

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