Thread by @mcrs987

Starship Hotstaging
A THREAD
Compiled by @mcrs987, inspired by @JoshLoweSpace
This thread shows my current theory on how Starship will hostage, using existing hardware we can see.
This was announced yesterday, so the majority of this is speculation
(1/24)

@JoshLoweSpace @SpaceX @MiniGCyt @DJEsmeraldMusic @RGVaerialphotos @FelixSchlang @MarcusHouse @Ringwatchers So let’s start off by completely ignoring this ring. This ring is what a lot of people think is for hot staging. I think contrary, for 3 main reasons. (Image via @tdsn19)
(2/24)

@JoshLoweSpace @SpaceX @MiniGCyt @DJEsmeraldMusic @RGVaerialphotos @FelixSchlang @MarcusHouse @Ringwatchers @TDSN19 Reason 1: This ring is obviously not very structurally sound with that many cutouts. SpaceX is already having problems with the payload door cutout on the ship, so having even larger holes probably wont help at one of the most critical points in the vehicle.
(3/24)

@JoshLoweSpace @SpaceX @MiniGCyt @DJEsmeraldMusic @RGVaerialphotos @FelixSchlang @MarcusHouse @Ringwatchers @TDSN19 Reason 2: That ring was marked for SCRAP over a week ago now, and there so far is no others seen. They have not worked on that ring at all since It rolled out and has been sitting outside tent 2 for about a month.
(4/24)

@JoshLoweSpace @SpaceX @MiniGCyt @DJEsmeraldMusic @RGVaerialphotos @FelixSchlang @MarcusHouse @Ringwatchers @TDSN19 Reason 3: If we assume that the struts in this ring get stringers, it would not match the same number of stringers that are on the booster forward section. Though it does match the number of stringers on the ship aft end.
(5/24)

@JoshLoweSpace @SpaceX @MiniGCyt @DJEsmeraldMusic @RGVaerialphotos @FelixSchlang @MarcusHouse @Ringwatchers @TDSN19 So, let’s get on to my idea. On January 6th, this mysterious ring with 20 holes and a bunch of stringers rolled out into the ring yard. Originally speculated to be for HLS, this ring was placed outside of tent 2 for a while and was recently scrapped. (via @LabPadre)
(6/24)

@JoshLoweSpace @SpaceX @MiniGCyt @DJEsmeraldMusic @RGVaerialphotos @FelixSchlang @MarcusHouse @Ringwatchers @TDSN19 @LabPadre However, a second one was spotted on May 23rd. This one is much cleaner and uses the same materials the rest of the ring use, rather than the milled steel of the first one. We can clearly see angled nozzles pointing up. (Image via @CosmicalChief)
(7/24)

@JoshLoweSpace @SpaceX @MiniGCyt @DJEsmeraldMusic @RGVaerialphotos @FelixSchlang @MarcusHouse @Ringwatchers @TDSN19 @LabPadre @CosmicalChief Though this specific ring was later sleeved with an eDome and placed outside the midday, and will soon become a part of the “midbay monstrosity” as I like to call it, there may be many more inside Starfactory being prototyped.
(Image via @RGVaerialphotos )
(8/24)

@JoshLoweSpace @SpaceX @MiniGCyt @DJEsmeraldMusic @RGVaerialphotos @FelixSchlang @MarcusHouse @Ringwatchers @TDSN19 @LabPadre @CosmicalChief This ring is what I believe will be used for the hotstaging system. It is clearly very rigid and allows for vent ports. Elon said yesterday that the hot staging will be used on IFT-2, so the current fleet of booster have to be modified.
(9/24)

@JoshLoweSpace @SpaceX @MiniGCyt @DJEsmeraldMusic @RGVaerialphotos @FelixSchlang @MarcusHouse @Ringwatchers @TDSN19 @LabPadre @CosmicalChief Elon said the booster would be ‘extended’, but did not specify how much. Just a single one of these rings would do the job. The video below demonstrates how they could convert the boosters.
(10/24)

@JoshLoweSpace @SpaceX @MiniGCyt @DJEsmeraldMusic @RGVaerialphotos @FelixSchlang @MarcusHouse @Ringwatchers @TDSN19 @LabPadre @CosmicalChief Though it may seem simple it is a bit more complex than I have illustrated it. All of the wiring and hydraulic lines to the clamps have to be extended one more ring, and would have to be shielded. Speaking of shielding…
(11/24)

@JoshLoweSpace @SpaceX @MiniGCyt @DJEsmeraldMusic @RGVaerialphotos @FelixSchlang @MarcusHouse @Ringwatchers @TDSN19 @LabPadre @CosmicalChief Notice the black dome here. We dont know what kind of shape they would use for shielding the sensitive hardware on the booster’s forward dome, so I just chose another eDome. They could coat it in whatever thermally absorbent material they use on the engine shielding.
(12/24)

@JoshLoweSpace @SpaceX @MiniGCyt @DJEsmeraldMusic @RGVaerialphotos @FelixSchlang @MarcusHouse @Ringwatchers @TDSN19 @LabPadre @CosmicalChief Now, let’s get into the reasoning of why I believe this is the way to go.
(13/24)

@JoshLoweSpace @SpaceX @MiniGCyt @DJEsmeraldMusic @RGVaerialphotos @FelixSchlang @MarcusHouse @Ringwatchers @TDSN19 @LabPadre @CosmicalChief Let’s go way back to the 1960’s, with the Titan 2 rocket. Titan 2 used hot staging. (Though, the interstage blew apart anyways) notice the jets coming out the side
(14/24)

@JoshLoweSpace @SpaceX @MiniGCyt @DJEsmeraldMusic @RGVaerialphotos @FelixSchlang @MarcusHouse @Ringwatchers @TDSN19 @LabPadre @CosmicalChief Titan used vent holes at the base of the interstage to allow the stage to separate cleanly without blowing itself up. The Titan 2 interstage is much longer than Starship’s so I feel theres less of a risk of it disintegrating
(15/24)

@JoshLoweSpace @SpaceX @MiniGCyt @DJEsmeraldMusic @RGVaerialphotos @FelixSchlang @MarcusHouse @Ringwatchers @TDSN19 @LabPadre @CosmicalChief Take a closer look at the interstage. Notice any similarities between it and this ring? Both have vent holes facing away from the direction of flight, meant to direct gas away.
(Image again via @CosmicalChief)
(16/24)

@JoshLoweSpace @SpaceX @MiniGCyt @DJEsmeraldMusic @RGVaerialphotos @FelixSchlang @MarcusHouse @Ringwatchers @TDSN19 @LabPadre @CosmicalChief Using this, and using a dome as a diverter for gas to escape through these vent holes, I believe we have found an efficient solution to this problem, without compromising the structure.
(image via @RGVaerialphotos)
(17/24)

@JoshLoweSpace @SpaceX @MiniGCyt @DJEsmeraldMusic @RGVaerialphotos @FelixSchlang @MarcusHouse @Ringwatchers @TDSN19 @LabPadre @CosmicalChief Another thing with this idea is that the Engine chill pipe isnt going to be vaporized. With the ring with cutouts from earlier the engine chill pipe would be in the middle of one of the holes, and would be vaporized. Not good. With this ring that doesn’t happen
(18/24)

@JoshLoweSpace @SpaceX @MiniGCyt @DJEsmeraldMusic @RGVaerialphotos @FelixSchlang @MarcusHouse @Ringwatchers @TDSN19 @LabPadre @CosmicalChief Also a fun bonus to this, if you make the vents able to open and close on command, you could use the thrust from the second stage to help flip the booster around
(19/24)

@JoshLoweSpace @SpaceX @MiniGCyt @DJEsmeraldMusic @RGVaerialphotos @FelixSchlang @MarcusHouse @Ringwatchers @TDSN19 @LabPadre @CosmicalChief Now, let’s talk ground infrastructure.
With an extension like this, the ship Quick Disconnect would be too low to actually reach the plate on the ship. They will have to extend the QD upwards. (Image via @RGVaerialphotos )
(20/24)

@JoshLoweSpace @SpaceX @MiniGCyt @DJEsmeraldMusic @RGVaerialphotos @FelixSchlang @MarcusHouse @Ringwatchers @TDSN19 @LabPadre @CosmicalChief This is actually less of an issue than it may seem. They are not moving the entire arm, just the QD plate. After the launch of S24/B7, the QD plate was removed from the arm, and the reason why is now obvious. They are upgrading it to fit this new height.
(21/24)

@JoshLoweSpace @SpaceX @MiniGCyt @DJEsmeraldMusic @RGVaerialphotos @FelixSchlang @MarcusHouse @Ringwatchers @TDSN19 @LabPadre @CosmicalChief They have actually done this in the past, between S20/B4, and S24/B7 as shown above
(22/24)

@JoshLoweSpace @SpaceX @MiniGCyt @DJEsmeraldMusic @RGVaerialphotos @FelixSchlang @MarcusHouse @Ringwatchers @TDSN19 @LabPadre @CosmicalChief This may also be why the QD arm at the LC39A starship tower has not been installed yet. SpaceX was anticipating this design change and is clearly waiting on starship to finish evolving so the designs wont have to be retrofitted last minute, like basically all of Starbase.
(23/24)

@JoshLoweSpace @SpaceX @MiniGCyt @DJEsmeraldMusic @RGVaerialphotos @FelixSchlang @MarcusHouse @Ringwatchers @TDSN19 @LabPadre @CosmicalChief Here’s some eye candy for y’all
(24/24)

@JoshLoweSpace @SpaceX @MiniGCyt @DJEsmeraldMusic @RGVaerialphotos @FelixSchlang @MarcusHouse @Ringwatchers @TDSN19 @LabPadre @CosmicalChief And this isn’t really that relevant but funny thing I noticed
@blueorigin predicted this 2 years ago LMAO

@AlbertoGirardi9 @JoshLoweSpace @SpaceX @MiniGCyt @DJEsmeraldMusic @RGVaerialphotos @FelixSchlang @MarcusHouse @Ringwatchers @TDSN19 @LabPadre @CosmicalChief that is true. here's where things get a little more complex
i think it's pretty obvious they are not going to fire it at full thrust while its staging, so theres less gas flow
also the products of starship's plume (mainly oxygen and water with some argon) are much smaller atoms..

@AlbertoGirardi9 @JoshLoweSpace @SpaceX @MiniGCyt @DJEsmeraldMusic @RGVaerialphotos @FelixSchlang @MarcusHouse @Ringwatchers @TDSN19 @LabPadre @CosmicalChief ..than the hydrocarbons that engines with kerosene fuel use

@AlbertoGirardi9 @JoshLoweSpace @SpaceX @MiniGCyt @DJEsmeraldMusic @RGVaerialphotos @FelixSchlang @MarcusHouse @Ringwatchers @TDSN19 @LabPadre @CosmicalChief CO2 is a pretty big molecule and thats what the majority of kerolox plumes are (hence why its not transparent compared to other plumes with different fuels
wikipeadia says titan 2 has an LR-91 engine on stage 2 which is a kerolox engine (RP-1 & LOX)

@SpaceMan1324 @AlbertoGirardi9 @JoshLoweSpace @SpaceX @MiniGCyt @DJEsmeraldMusic @RGVaerialphotos @FelixSchlang @MarcusHouse @Ringwatchers @TDSN19 @LabPadre @CosmicalChief i definitely think that's a possibility, but 3 engines at least, it has to have symmetrical thrust.

maybe just light the sea levels on minimum throttle (~30% iirc) and let physics do its thing

@fenkupng @JoshLoweSpace @SpaceX @MiniGCyt @DJEsmeraldMusic @RGVaerialphotos @FelixSchlang @MarcusHouse @Ringwatchers @TDSN19 @LabPadre @CosmicalChief couldnt be too perfect :)

@mgp2388 @RGVaerialphotos @JoshLoweSpace @SpaceX @MiniGCyt @DJEsmeraldMusic @FelixSchlang @MarcusHouse @Ringwatchers Titan 2, unlike Soyuz, has a closed interstage just like starship. Soyuz virtually has no interstage and its a straight passthrough of struts

@antonioetayo @JoshLoweSpace @SpaceX @MiniGCyt @DJEsmeraldMusic @RGVaerialphotos @FelixSchlang @MarcusHouse @Ringwatchers @TDSN19 @LabPadre @CosmicalChief part of whatever the heck they are building in the midbay

generally right now the midbay and everything near it is cursed hardware lol (illustration below is what's being built in the midbay so far)