(I've discovered that the weird "forest" vegetation in the background are Texas Palmettos. These are a variety of Palms adapted for semi-arid conditions.)
Presumably the flight plan for Sn11 will be the 4th iteration of the 8,9 and 10 test, once again in hopes of nailing the landing. If that doesn't succeed, the next Starship up to bat will be Sn15. They decided to skip over 12,13 and 14 after those were already begun. The reason is that 12,13 and 14 were to be essentially the same as 8,9,10 and 11. But starting with 15, the Starships will have significant improvements. 15 is expected to have much more heat shielding, a redesigned thrust structure, new propellant manifolds, and lots of improvements like that. Maybe better landing legs, but not sure about that. I think that they hope to commence more ambitious envelope-expansion test flights with 15. Supersonic at least and higher altitude. At some point they will be shooting for the Karman line and space. They will start evaluating reentry heating and stuff like that.
But... if 11 doesn't successfully land, they may have to deviate from that plan and devote 15 to landing too.
Another photo from the nsf stream showing Bluto the giant crane placing Sn11 on launch pad B. Static fire could be next week and launch maybe the week after that. Good chance that it wll fly before the end of the month.
(Mar 9, 2021 06:04 PM)Yazata Wrote: Here's Lab's recently resurrected Launch Pad Cam. 'Lab' really is his name, or rather his initials L.A.B., first name Luis.
Is that the same view? I don't recall that many obstructions in the way before. I'm probably confusing it with another cam service -- a little surprised at how far back into February I have to go to find something of LAB. (song: do u even miss me at all)
YazataMar 9, 2021 08:40 PM (This post was last modified: Mar 10, 2021 03:55 AM by Yazata.)
They are really pushing forward with 11. Elon is probably impatient after 2 1/2 landing failures. Time to get it right, people! (A week in Elon-time is like a year in human-time.)
One of the beauties of Lab's Pad Cam is that the audio picks up Hoppy speaking through its loudspeakers. A few minutes ago it announced:
"Attention pad: Hands-off vehicle at 2:30PM. Pad deck clear at 3:30PM. Pad clear and operators on console at 5PM. Cryoproof test flow 6PM."
So it looks like only 24 hours after Sn11 arrived at the pad, they are already gearing up for a cryo pressure test this evening!
And Austin Bernard delivers the goods!
Austin was peering up Sn11's skirt yesterday as it passed on the road, verifying that it does indeed have its engines already installed
And here's the SpaceX-ites yesterday between arrival of Sn11 at the launch area and its installation on its pad inspecting its highly suspect and clearly inadequate landing legs.
Elon replied to Austin's photo of the employees testing out the legs with this:
"Sn10 engine was low on thrust due (probably) to partial helium ingestion from fuel header tank. Impact of 10m/s crushed legs & part of skirt. Multiple fixes in work for Sn11."
Chris Bergin commented, "This is a tricky one given that I believe said helium pressurization was added to the CH4 header tank to mitigate what happened with Sn8. That's why it's a test program of course."
Elon replied, "Fair point. If autogenous pressurization had been used, CH4 bubbles would most likely have reverted to liquid. Helium in header was used to prevent ullage collapse from slosh, which happened in prior flight. My fault for approving. Sounded good at the time."
Some of the engineers [who post in the nsf forums] think that what happened in Sn8's CH4 header was something called 'ullage collapse'. It's the counter-intuitive idea that stirring the contents of a partially full tank of cryogenic fluid reduces pressure rather than increases it. And Sn9's radical pitch up flip maneuver obviously sloshed the contents of the fuel header. I'd never heard of ullage collapse until today, but below is an explanation of the phenomenon in cryogenic liquid hydrogen tanks, though I assume that the principles should be the same for liquid methane. Elon suggests that using helium to maintain pressure is just a temporary expedient until a better permanent fix comes along, presumably employing autogeneous pressurization from engine bleeds which is the long-term plan (not without its own challenges though).
Amazing how much information the engineers can squeeze out of a little off-hand twitter post.
I'll add that this is one of several reasons why I like Elon. If somebody brings Elon an idea that turns out in retrospect to have been not that good, and Elon approves it, Elon blames himself and not the guy whose idea it was. Elon wants his people to have ideas without fear of revealing them. (Though Elon is known for asking very tough questions so people with ideas need to have thought them through.)
Today they were going to do a cryo proof test at Boca Chica. Then they suddenly called it off.
Then around sunset... something happened that made them very happy. They were shooting off fireworks and 'Rocket Man' was blaring through loudspeakers! Looks like a big SpaceX employee party near the High Bay.
Turns out that it was a celebration of the anniversary of the beginning of the Boca spaceship building operation and all the great work that it's done in a comparatively short time.
YazataMar 14, 2021 12:14 AM (This post was last modified: Mar 14, 2021 12:24 AM by Yazata.)
They were planning to do a static fire on Friday but it was called off. Rumor is that it was a ground support problem with the tank farm or something, and not a problem with the rocket.
Plan now seems to be to static fire on Monday and if it's successful, to launch on Tuesday.
It's possible I guess, but these things almost always experience delays. So my personal guess is that the flight will probably slip to the end of the week if we are lucky. (We know that Elon is pushing to streamline the testing flow and speed things up.)
(Mar 9, 2021 07:16 PM)C C Wrote:
(Mar 9, 2021 06:04 PM)Yazata Wrote: Here's Lab's recently resurrected Launch Pad Cam. 'Lab' really is his name, or rather his initials L.A.B., first name Luis.
Is that the same view? I don't recall that many obstructions in the way before. I'm probably confusing it with another cam service -- a little surprised at how far back into February I have to go to find something of LAB. (song: do u even miss me at all)
The camera is in a slightly different place in order to get better pan shots. But the black tanks in front of the rocket are because the rocket is on launch pad B. (A is visible to the left, far less obstructed, and it's where 10 launched from. They seem to alternate using them in case repairs are necessary to the one they last used.)
YazataMar 18, 2021 04:00 AM (This post was last modified: Mar 18, 2021 04:21 AM by Yazata.)
Monday's static fire was attempted but appeared to have resulted in an immediate abort.
Road closures and flight tfrs for Tuesday were canceled. Since then people have been watching for an engine swap, but one hasn't been observed. Elon says that Sn11 is almost ready to fly and there are flight tfrs out for Friday and Saturday. But many observers (including me) don't anticipate a flight that quickly, if only because a passing weather front has brought high winds to Boca (40 mph gusts). It's likely that they will want to reattempt the static fire before they launch as well. (That's what I expect.) So we may be back where we were a week ago, static fire early next week and launch later in the week if the SF is good. It isn't clear what's going to happen.
Meanwhile there's plenty to see in Boca Chica's "Rocket Ranch". The place is a 100-ring circus, with frantic ant-like activity at both the launch site and the build site. It's paradise for those who love to watch very exotic heavy construction.
Construction continues at the new SuperHeavy launch complex which is a malestrom of excavators digging, concrete pouring, grading, forms and rebar. Elon apparently is tired of launching rockets Salvage-1 style, out in a field like he did with Hoppy. There's the blast-wall enclosed "bunker" containing pumps and valves, lots of trenching with pipes going in, foundations of unidentified structures, pile driving and construction of large circular structures that may or may not be the bases of huge tanks for propellants, water or something. The new tank farm is going in, plus earthworks like berms and retaining walls. It's believed that the foundations may be going in for the new launch tower and crane (that Elon says will catch the Super Heavy boosters, but we all know that Elon is crazy... right?)
On the other side of the landing pad lots of new concrete is being poured at Pad A, while Sn11 prepares for its flight at Pad B. (Elon must be by far the biggest concrete consumer in south Texas.)
Meanwhile a mile away at the Build Area, the shorter Giant Tent where nosecones are made is being enlarged. Many rocket and rocket-construction parts are accumulating, including things that nobody's been able to identify. Lots of deliveries, stainless steel straight from the steel mill, a big oil cooled electrical transformer, and most exciting, the long awaited bridge crane for the top of the High Bay. It's a big sucker, with a 180 ton lifting capacity. Meanwhile Bluto, the latest Giant Crane, has been getting a boom-extension allowing him to lift the new bridge crane and lower it through the roof of the highbay.
To say nothing of construction of a natural gas purifying refinery and a gas separation plant at the old gas well site just west of the build site in order to produce liquid methane from the ground and LOX and liquid nitrogen from the air.
And that's not all! SpaceX has been acquiring land at the Port of Brownsville too, across from where Deimos is currently anchored. Presumably to facilitate work on the oil drilling rigs turned rocket launch landing platforms. Phobos meanwhile is in a commercial shipyard in Pascagoula MS where they are really tearing into it, removing its oil drilling tower and most of its deck equipment so as to produce a flat-topped platform. And up at McGregor they are continually increasing their rocket engine testing capacity with new test stands. And Elon has left California and is now a Texas resident, living in Austin I believe. (There's a huge new Tesla factory under construction just outside Austin.)
Mary documents the crazy construction action here (check out the raptor fueling at the end of the video):
C CMar 18, 2021 04:23 AM (This post was last modified: Mar 18, 2021 05:49 AM by C C.)
(Mar 18, 2021 04:00 AM)Yazata Wrote: [...] Lots of deliveries, stainless steel straight from the steel mill, a big oil cooled electrical transformer, and most exciting, the long awaited bridge crane for the top of the High Bay. It's a big sucker, with a 180 ton lifting capacity. Meanwhile Bluto, the latest Giant Crane, has been getting a boom-extension allowing him to lift the new bridge crane and lower it through the roof of the highbay.
That's just way too much teasing of classical physics. Someday gravity is going to get irked.
Quote:And Elon has left California and is now a Texas resident, living in Austin I believe.
Even Austin might still be a ways from having a lingering piece of California, but close enough to mediate his withdrawal period from Golden State politics (like a nicotine patch). Arguably the nearest to a "leftangelical" area that Texas can provide.
YazataMar 19, 2021 12:38 AM (This post was last modified: Mar 19, 2021 01:45 AM by Yazata.)
Today turned out to be an exciting day for tank watchers. Opening act was SLS' successful 8 minute, full-thrust hot-run at Stennis.
Then this, the stacking of the first super big SuperHeavy booster in the High Bay. That stacking started right after the SLS hot fire completed, so I suspect the Boca Chica workers were watching their rival heavy lift rocket.
Elon was there to watch the birth of his baby and tweeted a photo of the process underway. Bluto is reaching over the top of the HB and down through the hole in its roof, suspending the top tank barrel over the bottom segment. It was gradually lowered onto the bottom where welders will fix it in place. That's underway now. Bluto will hold it until that step is completed. Then there's lots of integration tasks of connecting plumbing and electrical. But the workers have already done it over and over with the Starships and they know their jobs.
When they finally stack a full scale Starship on top of one of these that will be a sight to behold.
Michael Baylor pointed out that it was only a year ago that Sn3 collapsed in on itself and everyone was wondering if they could build a Starship fuel tank section that would hold pressure. They've come an amazingly long way in just months. Where will they be a year from now? The expectation is that they will have a Starship in orbit.
Somebody remarked that Elon needs to hoist a Starship above this so that people can see what the full stack will look like.
Elon says, "We will need launch tower for that. Hook height for the lift is ~140 m & both booster & ship need to be stabilized at stage separation joint."
Mar 8, 2021 09:47 PM
(This post was last modified: Mar 9, 2021 03:36 AM by Yazata.)
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