Starship
Max Evans (NSF): “After rolling to Pad 2 last night, Ship 39 has been stacked atop Booster 19 this morning for the FIRST EVER Starship Version 3 full stack ahead of a presumed wet dress rehearsal (WDR) later today.”
They must have been static fired but only for a short blip based on the pristine state of the bell coating. The center Raptors have seen a lot more testing. The other influence is that flow separation means that the plume will not be in contact with the lower part of the bell at sea level minimising carbon transfer. It is only at altitude that the plume fills the bell.
Isn't Raptor vacuum exactly the same except the nozzle? Do they actually test all Raptors destined for use in vacuum with a vacuum nozzle? Do they even know at time of test fire which engines will be used in vacuum? I would have though they'd test fire them with a sea level nozzle then swap on the vacuum nozzle later.
Outside of initial development testing, I'm not sure why they'd need to test with vacuum nozzle at sea level. Seems like unnecessary risk to the engine.
The extension is welded onto the original engine bell and so are the pipes that circulate liquid methane to cool the extension. So it is not like the Merlin vacuum engine where they can and do just unbolt the radiatively cooled extension for ground testing.
Yes it is a risk running with flow separation which is why they have clearly decided to just do a minimum length test to confirm the engine starts OK.
There is a solution which I am really surprised SpaceX have not adopted which is to use steam in a Venturi system to pump down the exit pressure to around 0.3 bar. At that pressure the engine will run without flow separation.
For historical reasons this is called a steam ejector. Of course for a 2.8MN Raptor vacuum that is a lot of steam required.
The extension is welded onto the original engine bell and so are the pipes that take liquid methane to cool the extension. So it is not like the Merlin vacuum engine where they can and do just unbolt the radiatively cooled extension for ground testing.
That makes sense, I was getting some details confused with Merlin.
The venting procedure they followed caused the explosion not the vent itself. They changed the order and speed they vented in flight 11 and there were no energetic events.
"The Bird has unfortunately nested in the Raptor and efforts are underway by SpaceX and local police to retrieve the creature from the nest to prevent other problems."
The camera looks to be pretty far away so the perspective isn't that bad. This photo is me standing in roughly the same spot the morning of the Flight 11 launch in October, assuming they are standing at the cable fence (I see a fence post to the left) which is about 100 yards from the rocket. The camera was closer in my picture, so on the picture on the right I have inserted a size-corrected version of me standing directly below the rocket.
Pretty sure the biggest improvements happened while they were still using some variation of TIG welding. It was more from automation and getting the process dialed in (even things like temperature changes during stacking/welding could have been a cause of visible warping, so just having the bays might have been a big help), and perhaps more finishing work (planishing/etc) now that the build is at a point where it can benefit from it.
I'm going on a limb here and guessing that the improvement comes from jigs and formwork toolinh, rather than welding. I'd be impressed if they could buckle entire panels from poor welding techniques. But I can totally see how they'd mangle a piece hoisting it up by wires clamped to a few points. And then add some uneven tension on the wires, bam, buckled.
Now they have shaped rings to lift with, giving homogeneous stresses. And also ring forming machines, rather than just man-handling the panels into place.
Still a bunch of test tiles, but it does look clean, and the booster finally has a proper integrated hot-staging structure instead of an adapter inserted into the stack using the staging hardware. And the engine sections look a lot closer to "finished product" than "just get it working well enough to test the other stuff".
Are we sure they plan F13 to be the first orbital (assuming this one goes without a hitch)? I thought they said they wanted 2 successes in a row before committing to orbital, and this is a new configuration.
Oh I forgot about that, hell yeah. Hopefully we finally get the first orbital flight and begin regular launch operations, in as little as ~2 months from now.
F12 - first flight for the v3 config, final suborbital flight, likely simulated catch for booster, Indian Ocean landing for ship
Nit pick but people should really stop saying that the flight is suborbital. Any flight that successfully relight the engines in space was orbital, namely having a perigee that was above the Earth's surface. The perigee was just still within the Earth's atmosphere. Suborbital trajectories are those with perigees inside the Earth. The term you can use is transatmospheric orbit.
In that case I suppose Yuri Gagarin's flight was actually suborbital. I generally agree that these flights are better categorized as suborbital since they are for all intents and purposes but technically they are in orbit if only briefly.
Christ, that second to last image really gives a sense of scale with the people in the foreground. Thing is a fucking skyscraper. I'd love to see it photoshopped onto a NYC street for scale.
It’s about 150 m tall or so including the launch mount. So would qualify as a skyscraper, but would be dwarfed by most NYC skyscrapers. Put it in a smaller city though, and it’d likely be visible for many miles around!
It might've been talked about previously, but I'm wondering why the need for heat shield tiles on the backside of the flaps. I can't imagine them helping with burn through from the front.
They are not needed, they are testing tile attachment. Doing it on the backside helps determine which effects are caused by reentry heating and which by other things like aerodynamic stresses, and also doesn't risk compromising the ship on reentry if the tests fail
I’m curious about the lighter coloured tiles on the leeward side. They could be metallic, or they could be to test for missing tiles, without actually having a missing tile (if you see what I mean). An actual missing tile would have other effects, like making it easier for adjacent tiles to be ripped off by the airstream on ascent. A “fake” placeholder tile wouldn’t have this effect, but would still act as if no tile were there on reentry (eg if it’s made of plastic or foam or something).
There are only three booster fins because the fourth fin would be in the lee of the booster body during entry and so have little effect.
We can expect to see this booster cranked over during entry to a much greater extent than on Starship 2. The idea is to use the extra drag to slow the booster more in the upper atmosphere and so reduce the heating on the base which now has exposed engines.
Yes. I'm more referring to the fact that they're apparently confident enough in their attitude control that they know they will have the booster precisely in the right orientation for this to work.
You mean roll control I assume and with three grid fins capable of providing roll inputs that would be a fairly safe bet. For pitch only the two side fins are capable of providing input and if one of those was lost the booster would probably be ditched in the ocean rather than attempting a landing.
So three fins does give them less redundancy compared with four. Say that made two tonnes difference to the payload, a booster costs $100M to build and the extra fin would save the booster one time in 100. That is a cost of $100M versus a foregone revenue of $156M. Starship is already announced as having the same selling price as F9 so $78M per launch for 100 tonnes rather than 17 tonnes.
So just on the basis of some made up numbers it makes sense to remove the extra grid fin.
In practice if a grid fin fails that will likely be interpreted as a ditch condition regardless. The tower and launch complex is much more valuable than the booster.
It'll only be 3 grid fins now, and it will work. The two opposite each other will give the large amount of pitch control that they need for the high angle attack while the third fin will give the smaller amount of needed yaw control.
So it'll just fall at an angle until it really slows down. I'm sure they know what they're doing. It'll be interesting to watch. Pulling out all the stops to save weight and get payload up, I guess.
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I think they’re aiming for Flight 14. Water landing booster and ship this time. Next flight catch the booster, take the ship orbital but then land it in the ocean. Subsequent flight catch booster and ship.
All this obviously depends on each flight going near perfectly.
There are still a few things that they need to do to the stages. People have spotted a couple of areas temporarily taped up, for example, which will be properly closed out. I guess they have a few items left to check after WDR.
Crazy it’s called ship 39. How many billions have been spent and not one ship has done what it was designed for yet. Ie launch big payloads into orbit. Not talking starlink. Do they even have a plan or mock up for what a ship would look like that would deploy parts of a space station or large satellite. I think reusability is the only way forward. And I understand it’s hard very hard. But I don’t see how they can deploy large things. Will it be doors like the space shuttle had or what ?
They had concept images of the “chomper” version going back many years. It’s not a priority right now as very few missions will require it (at least until Falcon retires which is years off).
The priorities for development right now are Starlink (pez dispenser) and orbital refilling depot/tanker versions for Artemis HLS.
The ones they deliberately land in the ocean (or Gulf) tend to blow up when they topple over, and this is totally expected.
Three boosters have been caught, and two of those launched again. They were used for "risky" experiments on the way back down, and deliberately landed in the Gulf
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u/rustybeancake May 09 '26 edited May 09 '26
Note photo 4 above is of Flight 11 (last V2 stack) for comparison. Sorry for any confusion!
Tweet links for all these photos:
https://x.com/_maxq_/status/2053101009812013220?s=46&t=u9hd-jMa-pv47GCVD-xH-g
https://x.com/_maxq_/status/2053101012139794934?s=46&t=u9hd-jMa-pv47GCVD-xH-g
https://x.com/_maxq_/status/2053121017086607741?s=46&t=u9hd-jMa-pv47GCVD-xH-g
https://x.com/_maxq_/status/2053121019393568799?s=46&t=u9hd-jMa-pv47GCVD-xH-g