This is, apparently, a total of less than 1.5 tonnes of separable payload going to, or near, 23,616 km x 56 deg while expending the first stage. For comparison, Falcon 9 lifted 4.35 tonne GPS to 392 x 20,163 km x 55 deg while recovering the first stage downrange. Perhaps the payload adapter that holds these two satellites adds enough additional mass to preclude recovery, but it seems a close call to me. Second stage disposal after spacecraft separation is part of the equation as well I suppose.
- Ed Kyle
Speaking of payload adapters, I sifted through the Arianespace press kits relating to the Soyuz Galileo missions and saw the adapter mass ranges between 150 to 180 kg.
Given a Galileo satellite weighs 733 kg, total payload mass is between 1,616 and 1,646 kg.
thats for a soyuz dispenser, not an F9 one...
Second stage disposal after spacecraft separation is part of the equation as well I suppose.
- Ed Kyle
I doubt that we will see a disposal in the ocean. Perhaps a two burn raising of the orbit to get it 200 kilometers or so above the operational Galileo orbit. Element sets may be available after launch and if so will provide that answer.
So far, the Galileo FOC satellites are not been deployed directly into their operational orbit of 23,222 km, but about 300 km above (Soyuz/Fregat) or below (Ariane 5ES).
The upper stages remained there, the satellites drifted to their slots and correct the orbit itself.
This is, apparently, a total of less than 1.5 tonnes of separable payload going to, or near, 23,616 km x 56 deg while expending the first stage. For comparison, Falcon 9 lifted 4.35 tonne GPS to 392 x 20,163 km x 55 deg while recovering the first stage downrange. Perhaps the payload adapter that holds these two satellites adds enough additional mass to preclude recovery, but it seems a close call to me. Second stage disposal after spacecraft separation is part of the equation as well I suppose.
- Ed Kyle
Speaking of payload adapters, I sifted through the Arianespace press kits relating to the Soyuz Galileo missions and saw the adapter mass ranges between 150 to 180 kg.
Given a Galileo satellite weighs 733 kg, total payload mass is between 1,616 and 1,646 kg.
That's for a Soyuz dispenser, not an F9 one...
But why not somehow attach the Soyuz dispenser to the F9 payload interface?
SpaceX picture of Falcon 9 vertical:
Sooty booster next to the clean upper stage almost looks like a bad photoshop job.
This is, apparently, a total of less than 1.5 tonnes of separable payload going to, or near, 23,616 km x 56 deg while expending the first stage. For comparison, Falcon 9 lifted 4.35 tonne GPS to 392 x 20,163 km x 55 deg while recovering the first stage downrange. Perhaps the payload adapter that holds these two satellites adds enough additional mass to preclude recovery, but it seems a close call to me. Second stage disposal after spacecraft separation is part of the equation as well I suppose.
This seems consistent with the published performance. I figured roughly like this. Starting from a 200 km parking orbit, you need 2180 m/s to get to an apogee of 23200 km. Then you need 1468 m/s to circularize. Finally there is about a 200 m/s penalty for the 56 degree orbit. So overall this is equivalent to a due-east LEO from the Cape + 3848 m/s. This works out to a C3 of 14. (Circular GEO is about C3=24, so it's consistent at least.)
Now if you go to the NASA performance calculator, you can select C3=14. It does not show F9 ASDS. But we can guess - if we ask for C3 = 10, and get a plot, we can extrapolate. At C3= 10, F9-ASDS payload is 2200 kg, and it looks like increasing C3 by 4 will drop that by about 600 kg. So F9 w/ASDS recovery can put about 1600 kg into the desired orbit. Add up 2 satellites, dispenser, disposal, and boiloff during coast, and almost surely the F9 cannot do this with recovery.
There should be plenty of margin with F9 expendable. A crude estimate goes like this. They can skip 20 seconds of 3-engine entry burn, and 30 seconds of 1-engine landing burn. That's 90 engine-seconds, so 10 more seconds of 9-engine thrust. Acceleration at burnout is about 3Gs, so that's about 300 m/s. So now instead of LEO+3848, you need LEO+3548. That's about a C3 of 7. This in turn gives a payload of slightly over 2500 kg. Could potentially even be enough for 3 GPS satellites, but maybe a 3-satellite adapter is too heavy, or 3 satellites don't fit in the fairing.
NSF webcast (video id zb8eVJhIp_U):
Watching from NC Outer Banks, about abeam of the first stage impact point. About 40% sky cover, so maybe some jelly, maybe not. T minus 2 minutes, looks like it's going.
Falcon 9 in Startup. LD Go for launch.
Staging; about 70% through 2nd stage flight. Too much clouds, no jellyfish viz.
From the front yard, we got a hole in the clouds and a beautiful view... one that unfortunately we don't get much anymore now that all the Starlink launches go southeast
