Scivillage.com Casual Discussion Science Forum

Mary reports that the image in the last post was only the thrust section being moved into the High Bay. The actual stacking is happening this afternoon and is underway as we speak.

https://twitter.com/BocaChicaGal/status/...9347069953

And while SN4 sits on the test stand and SN5 is being stacked, most of the structural parts of SN6 have already been identified as as-yet unassembled barrels and bulkheads. They really are mass producing these things with several underway at one, assembly-line fashion.

Lots of excitement Friday-Saturday night as a huge Biblical-style thunder storm plowed through the Boca area. SN4 wasn't visible in the rain deluge, but lightening was striking around the launch area almost continually. Seeing as how SN4 is the tallest thing in the area and is made of steel... So yesterday was devoted to inspections to make sure the electrical wiring wasn't fried.

Apparently it wasn't, since something is on for today. The road is closed with a roadblock the likes of which Mary has never seen before. An armored vehicle (MRAP) with Cameron Country SWAT written on it. They really don't want people going through their roadlock... (or maybe they are just scared of Elon.)

https://twitter.com/BocaChicaGal/status/...1105182720

Lab Padre's live-stream of SN4's antics



SpacePadreIsle speculates that the tide is unusually high today and they might have wanted to use a AWD high mobility vehicle like that to make sure the beach was clear.

(I was speculating that since Mexico is only a mile or two away at that point, maybe they got intelligence that the cartels were planning to smuggle drugs or something across in that area, perhaps hoping to use the SpaceX exclusion zone as cover.)

Speaking of Padre Island, the lightening before dawn Saturday morning ignited the largest fire that community has seen in decades, burning down a large condo complex. Thankfully everyone was evacuated in time and the only injury was a firefighter who appears to have suffered smoke inhalation. The fire was a true conflagration for several hours and all the firefighters could do was contain it, until another intense burst of thunder showers rained all over it and put it out.

Here's LabPadre's video of the South Padre Island fire



NSF is setting up their stream, featuring Mary, which should go live in a few minutes here

Another static fire today. The engine ran and seems to have shut down well, without the weird 600 Hz honk that has plagued earlier Raptors including sn18 a few days ago. (The honk sounds cool, even if SpX is trying to eliminate it.) But... after engine shutdown today there were some flames under SN4's skirt that required successful use of the fire-suppression system. Speculation among the armchair rocket scientists seems to be converging on the idea that some fuel line lost a seal and released methane that ignited. Probably little or no damage apart from the offending seal. As we remember, Hoppy endured far worse.

Edit: It's now five hours later and the road to the launch area is still closed. Vapor is still visible at SN4's base. Speculation is that when the tanks are drained of liquid propellants, they are then flushed with nitrogen gas to remove any remaining propellant vapors. And that safeing process may have been disrupted by whatever the problem was at the end of the static fire, leaving the vapor-filled cylinder as a stoichiometric explosion risk.

Edit2: Here it Wednesday morning, some 24 hours later and the road is still closed and the pad is still clear. Cameron County says that the road closures are on until 6 PM this evening. The SpaceX drone has been spotted flying nearby looking at SN4. I get the impression that they have a real problem on their hands and aren't sure what to do about it.

Here's Spadre's short video clip of the static fire. 



And LabPadre's slo-mo showing the anomaly at the end of the static fire

Last night the road closures were extended until 5 AM this morning, approaching 48 hours after the anomaly. Then a bigger drone showed up about 1:30-2 AM with a bright steerable spotlight and no doubt cameras. It slowly circled SN4 and seemed particularly interested in some of the piping on its exterior. Then it disappeared.

This morning, the SpaceX firetruck, a police car and some SpaceX vehicles drove down the road and had a little conference by the launch pad gate. They were apparently satisfied and delivery trucks and workers cars started entering the site. Right now there are many workers there and there are lifts up under SN4's skirt inspecting things.

Externally, the vehicle looks fine. The only visible damage is some fried tatters on the test stand. Don't know what it was, perhaps some cables wrapped in something, but the heat destroyed it, whatever it was. The new paint on the stand looks gone. But nothing that can't be easily repaired. The exception would be the engine itself. They need to ascertain that it's undamaged. I expect that it's fundamentally ok, it's a rocket engine after all, built to withstand heat. But it's complex, and there are lots of lines in its Medusa's hair coiffure. Something evidently broke and was spewing methane after the test. So they need to locate that.

LabPadre says that a powerful thunderstorm is heading in from the west.

The thunder storm kind of faded before it hit Boca. Nothing much.

They are already cleaning up the test stand from Tuesday's misadventure .

Something big is on tap for Thursday May 28 or Friday, Sat, Sun or Mon following through June 1. (Starting the day after DM-2!) Major road closures. Not sure if it will be SN4 finally flying, or testing on the new SN5 which is taking shape. Maybe more SN4 static fires, given that the last one didn't end well.

SN5's tank section is largely completed and they are finishing a nose-cone to place atop it. It's clear that they plan to fly that nose since it's got built-in control thrusters. So SN5 will be the the first Starship with a pointy-end as well as a flamey end. It won't have fins though, so it will look more like a bullet than a spaceship.

An upcoming hop is indicated by the fact that they are busily clearing all the stuff off the landing pad, which they've been using as a storage area since Hoppy landed there last August. And some of Hoppy's newly installed eyes are peering towards the landing pad, suggesting that something is expected to happen there.

Just to add intrigue, the Giant Crane is setting up at the launch area next to SN4. So do they plan to remove SN4 from the test stand to make room for SN5? If so, I'd expect them to remove SN4's engine first. That's the most valuable part. No sign of them doing that yet, so it isn't clear what's happening.

Nomadd captured Hoppy letting its inner Dalek out by attacking its new rival.

(Actually Hoppy is some distance from SN4 and the picture is lined up with the flare in the middle. Hoppy hasn't turned homicidal and isn't shrieking "Exterminate! Exterminate!" through its new speakers.

Don't expect anything exciting in Boca for the next few days, since Elon has announced that there won't be any big tests there while SpaceX has its attention focused on the DM-2 mission. He told Aviation Week that he actually doesn't expect a hop test for several weeks, probably because a flight is waiting on FAA approval (and government offices make snails look fast by comparison). The visible damage from the fire has seemingly been repaired and SN4 looks fine.

But Mary did produce a bit of news: She spotted come rings with "SN7" written on them, so there are parts of three additional Starships backed up behind SN4. SN5's cylindrical tank section appears complete and is awaiting installation of its pointy nose, whch is sitting nearby. Meanwhile much/most of SN6 has already been spotted, in a number of barrel sections that haven't yet been joined together and stacked.

And here's LabPadre's latest video flyover (in a Cessna from Port Isabel) of the launch area. The biggest change visible is how all the accumulated stuff has been moved off the landing pad, which has recently (last few days) been expanded much larger with new concrete. The stuff has been relocated to the future SuperHeavy launch pad area which seems to be their new storage area in the short term.

SpaceX just slipped in a new static fire of SN4 in Boca, just a day after DM-2 was scrubbed at Cape Canaveral (caught me by surprise, it was being live-streamed but I missed it). This one took place without any fires or other anomalies.

https://twitter.com/NASASpaceflight/stat...5759751169

LabPadre's video of the static fire



The new addition to SN4 was the box shaped thing perched on top of it. It was installed just yesterday by the Giant Crane. It contains two 'coils' (rolls) of sheet stainless steel that were previously in the junkyard area, each one estimated to weigh about 10 metric tons ('tonnes'). So that box is ballast that weighs some 20 'tonnes'. Unclear why it was installed there. Speculation is that it's meant to simulate the mass of a nose fairing up on top.

Mary's video of it being installed



Breaking News! --- The FAA has just minutes ago granted a license for Starship suborbital flight tests from Boca!

"Space Exploration Technologies is authorized, subject to the provisions of 51 USC Subtitle V, ch. 509, and the orders, rules, and regulations issued under it, to conduct suborbital reusable launch vehicle (RLV) missions.

General. Space Exploration Technologies is authorized to conduct RLV missions to launch the Starship Prototype Launch Vehicle. The RLV missions authorized by this license commence and conclude at the Boca Chica launch and landing site, Boca Chica, Texas."

https://www.faa.gov/about/office_org/hea...)lliu1.pdf

Issued May 28 and remains in effect for two years, until May 28, 2022.

It's being noted that this is a launch license, similar to those granted to Falcon 9's, unlike the experimental test permit that Hoppy had. It isn't just for one particular flight, it specifies missions (plural) and doesn't specify a maximum altitude, so Starship needn't stay below 150 meters and even crossing the Karman line seems to be acceptable. SpaceX is required to report any anomalies during testing to the FAA and SpaceX is required to have $198 million in liability insurance.

Prepare to see some amazing things in coming months as they test out their very unorthodox landing plans (falling sideways most of the way down, then a sudden 90 degree pitch-up and final propulsive landing). Then trips up to space and back as reentry plans are tested. Orbital flights will require a Superheavy booster, and that will require another license.

And there's a new NOTAM announcing temporary flight restrictions at Boca on Monday. This extends to 26,000 feet! My guess is that there's no intention to fly SN4 anywhere near that high, but they may try to hop it (like Hoppy).

https://tfr.faa.gov/save_pages/detail_0_3903.html

They don't seem to be done.

This afternoon, after the static fire in the preceeding post was concluded, Nomadd reports that sheriffs went through the little one street one block long Boca Chica village and handed out these:



As Nomadd said when they did it earlier, "There are police at my door again. I hate that!"

CATASTROPHIC FAILURE!!!

The static fire seemed to go well, though the engine run was very short.

SN4 looked fine afterwards... for a few seconds.

Then there was a big release of liquid oxygen from the bottom as (speculation) the thrust dome gave way. A moment later, the liquid methane went up in a massive explosion. My guess is that the common dome gave way and the methane mixed with the LOX and the whole thing violently detonated.

The geeks are rerunning the video of the explosion frame-by-frame.

There's a visible shockwave and all kinds of large metal fragments flying away in all directions. The test stand is mangled and the blackened remains of SN4 is laying on its side. The flare-stack is out and it's bent. One of the "three amigos" water tanks was nailed by debris and punctured. The new mass simulator didn't move at first, then came free and flew upwards out of the frame. It weighs 44,000 pounds and must have flown 100 meters high. Somebody did the math and says the mass simulator left the scene at about 550 km/hour.

Apparently the sheriffs weren't kidding when they warned about what they called an "over-pressure event".

Mary and Nomadd report that they are ok. (Mary's by the sheriff's roadblock.) She has audio of the explosion that nobody has heard yet. Nomadd reports that it was loud. Unclear if windows were broken.

Here's a clip (shot by Mary) showing SN4 starting right after the conclusion of the static fire, showing the subsequent explosion.

https://twitter.com/NASASpaceflight/stat...7848960000

SpaceX vehicles have passed through the checkpoint, then they stopped about halfway to the pad.

Chris B reports multiple mainstream news outlets are contacting him to get rights to use Mary's video. To his credit, the answer to all of them is 'No'.