Scivillage.com Casual Discussion Science Forum

Boca Chica's a hive of activity!

And Elon's apparently there and busily tweeting!!!!

https://twitter.com/elonmusk/status/1176009047729954818

"Bottom half of Starship at night. Top half with forward fins & header tanks probably stacks on Wednesday. Three Raptors already installed."



Here's a little video that Elon posted showing stuff inside one of the Boca Chica buildings waiting to be installed:

"Raceway & flap hinge aero covers"

https://twitter.com/elonmusk/status/1176007759751499776

The indefatigable Mary/BocaChicaGal is back from vacation and is cranking out amazing photographs too. (This woman is more deserving of a Pulitzer Prize for photojournalism than anyone who will end up winning.) You can watch things changing by the hour.

I'm still watching the fins. They don't seem to really be attached yet. So are they just set there for looks, to show people at Elon's big upcoming Starship unveil event this Saturday (9-28) what the finished version will look like, or are they awaiting some more serious installation coming in the next few hours/days? (More of life's mysteries...)

Elon says that they are installing batteries up in the nose fairing. And Mary/BCG has photographed things that the NSF engineering geeks have identified as... Tesla battery packs! Makes sense, actually.

They are working on the nose this morning. As Elon says, they are packing all kinds of stuff inside it, in order to get a better mass balance with the heavy engines at the rear. (Important for aerodynamics.)

How they are going at it is interesting. They raise the partially assembled nose with a crane, then lower it atop whatever piece of gear they plan to incorporate. In the photo below (from Labpadre's stream) it's a grey header tank. Then when the nose is set atop the new item, they run a cable from the crane through the little hole at the very tip of the nose and hoist the new item up where workers inside fix it in its designated place on the structural members shown being installed on last Wednesday.



Here's a photo by Mary/BCG showing the other header tank (there are two) with Tesla battery packs being attached to it. These appear to be Model S/X automobile batteries. 

https://www.teslarati.com/wp-content/upl...24x534.jpg

There's also lots of work underway on the sides of the fuel tank half constructing "raceways". These are conduits on the outer skin of the vehicle carrying all kinds of things, such as fuel/oxidizer from the header tanks, pressurized gases for the control thrusters, plus all kinds of electrical cabling. The vehicle is constructed such that the skin and the tanks are one and the same. So anything going from top to bottom has to pass through the tanks or else outside the vehicle's skin.

The raceways are being covered by interesting assymmetrical 'aerocovers'. (The things shown lined up in Elon's weird little video yesterday.) I'm not clear why they are assymmetrical, one speculation from a very experienced aerospace engineer was that they will induce flow separation when the vehicle is reentering the atmosphere in kind of a belly-flop/skydiver position. That's a bit above my pay-grade and I'm not clear why a designer would want to do it, since aeronautical engineers typically try to reduce flow separation on aircraft because it increases drag. But maybe drag is precisely what a spaceship designer wants in reentry where the goal is to decelerate. (Convert the kinetic energy of the vehicle into energy in the air vortices it leaves in its wake... or something like that...)

Photo by Mary/BCG showing a raceway in process of installation:



Things are happening very rapidly in Boca Chica, but it's also pretty clear that this thing will be nowhere near completed on Saturday, when Elon makes his big unveil presentation.

Here's a cool little video just a 30 seconds long where Tim Dodd explains (using Kerbal) how Starship can control pitch, roll and yaw with just 4 flaps, two in the nose and two in the tail.

https://twitter.com/Erdayastronaut/statu...6464479232

Elon likes it, "That's correct. Essentially controlled falling, like a skydiver."

https://twitter.com/elonmusk/status/1176557352964591620

More of Elon's latest tweet-storm:

https://twitter.com/elonmusk/status/1176557685820387328

Viv asks: "Might be super obvs to everyone w/ an engineering background ... but what's used to actuate the fins? Some kind of small motor?"

Elon: "Many powerful electric motors & batteries. Force required is enormous, as entire fin moves. More about this on the 28th."

Still more:

https://twitter.com/elonmusk/status/1176559598368460800

"It does actually generate lift in hypersonic regime, which is important to limit peak heating"

Scott Manley replies: "And just like that I need to rebuild some of my descent models. So the AoA won't be 90 degrees, it'll provide lift to keep vehicle out of denser atmosphere until it loses enough speed."

Elon: "Exactly. For reusable heatshield, minimize peak heating. For ablative/expendable, minimize total heat. Therefore reusable like Starship wants lift during high Mach reentry for lower peak, but higher total heat."

An impressive new something rolled into Boca Chica this afternoon. It seems to be a huge new crane, but it could be a sci-fi laser battlestation.

https://forum.nasaspaceflight.com/assets...584053.jpg

https://forum.nasaspaceflight.com/assets...584059.jpg

It's the pieces for a Liebherr 11200-9.1 telescoping crane, one of the biggest in the entire world, capable of lifting up to 1,200 tons with a maximum hoist height of 188 meters.

Pretty clearly it's going to be a major player in the stacking of the Starship, which is supposed to happen tomorrow.

It's already set up and they are practicing with it as we speak.

Live feed here:

https://www.youtube.com/watch?v=-aDOpyUmfL4

(Sep 25, 2019 04:16 AM)Yazata Wrote: [ -> ]An impressive new something rolled into Boca Chica this afternoon. It seems to be a huge new crane, but it could be a sci-fi laser battlestation.

https://forum.nasaspaceflight.com/assets...584053.jpg

https://forum.nasaspaceflight.com/assets...584059.jpg

It's the pieces for a Liebherr 11200-9.1 telescoping crane, one of the biggest in the entire world, capable of lifting up to 1,200 tons with a maximum hoist height of 188 meters.

Pretty clearly it's going to be a major player in the stacking of the Starship, which is supposed to happen tomorrow.

It's already set up and they are practicing with it as we speak.

Live feed here:

https://www.youtube.com/watch?v=-aDOpyUmfL4

Putting together and stacking a starship outdoors instead of inside a gigantic building seems so boondocks and honkytonk. It's like Zefram Cochrane assembling the first warp-drive spaceship in the wilds of Montana sometime after WWIII. Next thing you know a Vulcan survey ship will detect Elon's advanced Raptor engines signature and transpiration cooling system in the upper atmosphere and establish contact.

During the night they lifted the nose (which is now filled with heavy tanks and batteries)



And plopped it atop the pretty much empty top-half fairing. (In the operational versions that's where the cargo and crew will go.)

Photos from the Labpadre stream which you can watch live here

https://www.youtube.com/watch?v=-aDOpyUmfL4



There is some surprise that the canards (controlled by Canardians?) aren't installed yet. Those little nose wings will probably be easier to attach before the thing is fully stacked. Presumably their actuators and fittings are already installed. And some time will be spent structurally joining these two segments. Lots of piping and electrical wiring will remain to be connected before it flies as well.

Edit: BCG to the rescue! She is on-scene and has posted closeup photos of the nose showing holes in the skin where the canards will presumably attach. (One might be visible in the photo above, the black rectangle above and to the right of the orange manlift.)

Not clear what's going to happen with the bottom tank half. Presumably it's going to be removed from the concrete ring it's currently sitting on and placed on some kind of support structure. (Maybe on a RollLift crawler, maybe not.) As far as is known, it still lacks its own legs. None of the SpaceX watchers are really sure about how that will work. Then the whole top half (which is mostly empty) will be placed atop the bottom half (which is mostly currently-empty fuel tanks). So while they are massive, they aren't as massive as their size suggests. They are sort of like giant empty beer cans. (The size of sky-scrapers with rocket engines attached.)

There's speculation whether or not that final stacking will really happen today. Lots to do first. Might be tomorrow.

There's back-of-the-envelope calculations about how much force will be required to move the fins in supersonic airflow. Lots of energy required. Speculation that Elon's going to be using multiple Tesla model S automobile motors. He's said that he will be talking about this on Saturday. There's also speculation about whether the Tesla batteries will be able to handle the load, which will run to something like 1.2 megawatts for short periods. But if (as reported) the batteries can produce 450 kW for short periods and there are six of them, 6 x 450 = 2.7 mW! The batteries will get really hot though, which might be why they appear to be attached to the LOX header tank which may conceivably circulate coolant through them. (In their automotive application, they circulate a glycol coolant.)

The bottom tank section has been lifted off its base and is now suspended from the Giant Crane
Video of that here

https://www.youtube.com/watch?v=JqWx-Ze2c-A

More here:

https://twitter.com/SpacePadreIsle

https://twitter.com/SpacePadreIsle/statu...9568233472

It may have been set down on one of those big blue RollLift crawlers, like the one used to move Hoppy.

https://twitter.com/SpacePadreIsle/statu...6200942593

Edit: And the crawler's been crawling! Now it, with the bottom tank-half riding atop it has taken a Tesla-joy-ride past Ironhenge and has pulled up closer to the nose half. Presumably in a spot where the Giant Crane can position itself within reach of both of them.

Mary/BocaChicaGal across the road from the SpaceX RV and Earth's most out-of-this-world DIY project. She's all happy because Elon Musk invited her to his big presentation. I think that's very cool. He's not just inviting the usual media, he's also inviting people who really care, who feel the same passion that he does.

https://twitter.com/BocaChicaGal/status/...5747144704

Here's the bottom half of Orby out for its wild joy ride, like a teenager in a stolen car

https://twitter.com/jason_corbettt/statu...4324323328

Best view I've seen of the blue RollLift crawlers with some kind of steel platform on them supporting Orby's bottom half. These blue babies aren't finished either. The finished twice-as-tall Starship will ride these crawlers for a mile down the road to the launch area near the beach. And presumably will need them to get from the landing pad back to the launch area after each flight. I don't know if the crawlers will be stationed at Boca Chica permanently, or will be on-call. (Not sure where they are based. Houston or some place like that.) SpaceX probably has to pay for them and their crews by the day. These crawlers are how the Florida Starship will makes its way partway to Cape Canaveral too. So RollLift is probably very happy to have SpaceX as a very prominent customer.

https://twitter.com/elonmusk/status/1177049277375250434

Photo from Elon Musk



Elon also says that Starship will have 6 landing legs, two under each fin, and two windward and two leeward. He says six should make it easier to land on uneven ground (like on Mars).

SpaceX workers were lined up to watch the stacking this afternoon (and every one of them driving a one ton pickup!)

https://twitter.com/SpacePadreIsle/statu...9925282817

But it didn't happen. Apparently more work remains to be done. Even if they leave the canards until later, the nose cone that was plopped on top of the top half fairing last night still hasn't been fully welded in place so the top half still can't be hoisted into the air by its nose with the giant crane.

In Florida, the security guards tell the SpaceX watchers to get lost. In Texas, SpaceX workers walk over and give space-nuts frozen popsicles

https://twitter.com/SpacePadreIsle/statu...0604686343

https://twitter.com/BocaChicaGal/status/...2373962758

It still hasn't been stacked yet. Whatever the delay, they are working furiously. It looks like every boom-lift in the state of Texas is at Boca Chica. Work seems to be centering around installing the lower fins and trying to make the nosecone fit right. Still no nose fins.

https://twitter.com/SpacePadreIsle/statu...2503160833

And Elon Musk posted this glimpse of what's under Orby's skirt. The three engines still aren't fully installed since no gimbal actuators are visible and much of the plumbing isn't there. (You can see the LOX downcomer fittings in the center of the circular thing, with no connections to the engines (yet). It is a good science-fiction look though.

https://twitter.com/elonmusk/status/1177314408604680192

The nose has acquired its eagerly-awaited ears (or maybe bat-wings)!

And the results of all the work on the tail fins is visible.

Now they seem to be preparing to stack the top half on the bottom half.

Live video here:

https://www.youtube.com/watch?v=-aDOpyUmfL4

Edit: It's rising!

Photos by BCG:

https://twitter.com/BocaChicaGal/status/...8126977025

https://pbs.twimg.com/media/EFearm5WkAIl...name=small

https://pbs.twimg.com/media/EFfGmJWXYAAl...name=small

Check out this photo particularly. It's a beauty! (Mary outdid herself!)

https://pbs.twimg.com/media/EFfSGRbWoAAS...me=900x900

There are men inside, on top of the top tank bulkhead, guiding the top half into place. I saw hands poking through the gap. (Seems dangerous.)

Photo below by Elon Musk. It's foreshortened so as to make the vehicle look shorter than it really is (and perhaps a bit more phallic).

This is what a spaceship is supposed to look like, damn it!



The six retractable Falcon9-style landing legs are being installed in steel housings around the bottom circumference.