This discussion got stared in the FH thread but should be here.

The discussion was about how many Starlink sats could fit in the faring or lengthened faring on the FH.

If the dimensions of 4m X 1.8m X 1.2M are correct then even a lengthened faring would only hold 15 sats at a mass of ~7.5mt. Without a longer faring then only 10 sats.

At only 10 sats per launch in order to get to 800 sats in 2 years of launching requires 40 launches a year of just Starlink sats in starting in mid 2019 and by mid 2021 would have 800 sats. But 40 addition launches per year above the already ~25 launches per year is a total of 65 launches per year. In order to achieve those rates Boca Chica would be launching at the rate of 12 per year, 40 and 39A at the rate of 2 /month each (weekly launches from the combined pads), and VAFB SLC-4E at at least 6/year.

If the size is correct then this represents an explosion in the launch rate starting in mid 2019. Jumping from up to 30 to more than 60.

This table from the FCC describes the satellites. However it is unclear.It describes a satellite with a body dimension of 4*1.8*1.2m

As mentioned in my post quoted a few posts ago include, shapes which have a maximum dimension of 4*1.8*1.2m include ones which can pack 22 into a standard fairing.

(4m tall pie wedge shape).

No reasonable person would describe a 4m tall or long thing as 'refrigerator sized'.

1.8*1.2*1.2-0.9*0.6*0.6 would be consistent with refrigerator sizes, the latter would require an unlikely density, to hit the above mass of 386kg, the former would be reasonably consistent with Iridium satellite density.

To avoid doubly folding the solar panels, and to get 2m*6m solar panels on the thing, it seems reasonable the overall dimension when packed would be ~2m in minimum height, with five panels lying against the sides, each of 1.2m wide.

Coincidentally, this is very close to the size of the dragon solar panels. (I was lazy and measured from

this paper model )

If we want to fit such a satellite in a 4.6m diameter fairing, one idea that springs to mind is a pie wedge design, with a 60cm core.

If we imagine several whole pies stacked vertically at 1.3m spacing, with eleven satellites per pie, that comes out as 55 on 5 pies, with perhaps another 5 on top.

The short side adjacent to the core would be mostly filled with folded solar panels, which have 16cm for 10 panels.

At 386kg (say 450 total plus dispenser) per satellite, this is 24000kg.

This is one possible design which is consistent with the available data, and seems broadly consistent with what's possible.

It implies that the existing fairing may be quite adequate for Falcon 9 to max out mass, given published data on Starlink sats, requiring only 14 launches to get 800 up with the standard fairing.

Or considerably fewer launches with Falcon heavy and a larger fairing.

If you want to argue you can only fit 10 in a Falcon 9 stock fairing, that means that the packed density is well under half that of Iridium-next.

Given that Starlink was carefully designed with insider knowledge about F9 and plans for the future, presumably with no thought given to not launching on F9/F9H - it would seem ridiculous for this to be the case.

Especially as they know they're going to be spending >>$1B on launch costs, and are not buying pre-designed satellite busses that are not optimised.

A much larger fairing is also a much heavier fairing, and if you're spending 4 tons of launch on a fairing expansion, and launching 40 per year, spending even several hundred million dollars getting your satellites down to a more dense packing makes sense.