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Big Starship presentation later today. It's an unveil (not like people can't already see it) and a sorta-technical discussion of why they designed it the way they did and what their reasoning was.

They say: "SpaceX's Starship and Super Heavy launch vehicle is a fully, rapidly reusable transportation system designed to carry both crew and cargo to Earth orbit, the Moon, Mars, and anywhere else in the Solar System. On Saturday, September 28 at our launch facility in Cameron County, Texas, SpaceX Chief Engineer and CEO Elon Musk will provide an update on the design and development of Starship."

It will be livestreamed here:

https://www.youtube.com/watch?v=sOpMrVnjYeY

Time is 7 PM CDT Sept 28 (5 PM PDT, 8 pm EDT, 00:00 UTC Sept 29)

Developments today are them finishing the landing legs, or at least the fairings that will house them. Along with installation of a tiny cap that will cover the small hole in the tip of the nose.

Edit: A thunderstorm just went through Boca Chica and was gone in 30 minutes, but high winds forced them to temporarily abort installing the nose cap. There was some concern among onlookers that wind might topple Starship (remember Hoppy's long-forgotten nose) but word is that Starship is secured to the ground for precisely this reason.

https://twitter.com/nextspaceflight/stat...4501960707
(Sep 28, 2019 05:48 PM)Yazata Wrote: [ -> ]... It's an unveil (not like people can't already see it) and a sorta-technical discussion of why they designed it the way they did and what their reasoning was.


A good thing that it wasn't draped and arousing mystery beforehand; and not resting on a pagan temple ground of symbolic monuments. With druid-like sculptors and fertility mystics explaining the reasoning and abstract significance.
Presentation has been pushed back an hour. Reason appears to be more thunderstorms.

https://twitter.com/SpaceX/status/1178058268331012096

Meanwhile Elon was seen riding a boom lift and crawling inside Starship through an access port.

https://twitter.com/thejackbeyer/status/...7148115968
(Sep 29, 2019 12:48 AM)Yazata Wrote: [ -> ]Presentation has been pushed back an hour. Reason appears to be more thunderstorms.

https://twitter.com/SpaceX/status/1178058268331012096

Meanwhile Elon was seen riding a boom lift and crawling inside Starship through an access port.

https://twitter.com/thejackbeyer/status/...7148115968

Good grief. Just like a launch delayed by weather.
(Sep 29, 2019 04:20 AM)C C Wrote: [ -> ]Good grief. Just like a launch delayed by weather.

The presentation was outdoors, so couldn't have all the guests thoroughly soaked (even though human beings are amazingly waterproof). As it was, the wind was still gusty.

Video of the presentation here. The second half, after a short intermission, was Q&A with more details. (It's youtube, so sorry for the ad it begins with)

https://www.youtube.com/watch?time_conti...OpMrVnjYeY

New renders from SpaceX, from last night's presentation

A serious Moon base (with a big solar power farm). Starship promises to eventually be able to deliver 100 people and upwards of 100 tons of cargo to the Moon's surface, per trip. The idea is to have a growing fleet of them and to fly them repeatedly with minimum turn-around. Want a whole network of human activity on the Moon? Cities, factories, mines, labs? (So when Leigha looks at the Moon with her telescope, she sees lights up there?) Well, this is the way. (Why hasn't NASA ever envisioned anything like this?)

Once a crazy visionary shows that it can work (assuming it ever does) everybody -- NASA, ULA, Boeing, the Russians, the Chinese, Blue -- will be trying to do it too. Worked that way with reusable boosters. Crazy... until it succeeded. Now SpaceX increasingly dominates the commercial satellite launch business, operating in the black while underselling the competition by flying cheaper (but still reliable) used boosters. So everyone suddenly has reusable rockets on their drawing boards, but still years away. All while SpaceX gains experience flying, recovering and re-flying them.

[Image: EFmQFf1U0AAVyJN?format=jpg&name=small]

Starship ventures a bit further out. It has at least the potential to take human beings anywhere in the Solar System.

[Image: EFmQYMKU4AEbAiU?format=jpg&name=small]

Elon says that he watches LabPadre's 24/7 Boca Chica webstream. He says that it's easier to see what's happening at Boca by watching the stream than by making phone calls.

It's a pretty dramatic view today, Sunday, about 6 PM local. Another thunderstorm is rolling through. The rocket is brightly illuminated but the clouds behind it are almost black with occasional lightening flashes.

https://www.youtube.com/watch?v=-aDOpyUmfL4
Summary of Elon's presentation by Slarty1080 on NSF:

SpaceX Starship/Superheavy update Boca Chica 28/9/19 summary

0:00 Intro, background and summary of previous achievements including Falcon 1 flight and first Falcon Heavy flight videos.

14:00 Starship diagram: 50m long, 9m diameter, propellant mass 1200 t, cargo 150 t, return cargo 50 t, error in diagram over Starship dry mass. Prototype 200 t, target 120 t, 110 t exceptional, 99 t aspirational.

16:15 re-entry animation 60 degree entry at Mach 25

18:55 animation of Starship landing

19:23 diagram of Starship engines 3 central gimbaling 15 degree sea level Raptors Isp 330 s 200 t thrust at sea level. 3 fixed peripheral vacuum Raptors Isp 355 s Aspirational sea level Raptor Isp 350+s, vacuum Isp Raptor 380s

21:08 Heat shield diagram: ceramic hexagonal tiles. Low maintenance, rapid production and install like glass vermicelli and crack resistant.

22:26 301 stainless stronger at low temperature and has higher melting point than Al/Li or composites. No shielding required on leeward side. Windward side thin ceramic tiles

25:00 carbon fibre costs130,000/ t, Stainless steel 2,500/ t.

26:29 Booster animation. Max 37 raptors (Elon not sure it will go that high), min 24 Rapters, more likely 31 Raptors. Length 68m, propellant capacity 3,300 t, 9m diameter, 4 diamond shaped grid fins. 6 large fins at base housing the 6 landing legs. 7500 t force at lift off, roughly 5000 t gross lift off mass. High thrust to weight is beneficial on a reusable rocket.

28:40 Raptor fire video.

29:48 Star hopper flight.

31:00 Size comparison chart

31:30 Animation of full stack launch and refuel

34:35 Propellant settled by milli-g acceleration using control thrusters.

36:30 Starship landing on Moon illustration.

37:00 Starship near Saturn illustration.

37:15 Need to concentrate on the fastest path to a self-sufficient city on Mars illustration.

Questions

49:26 Q) Can you tell me about the flight test programs?
A) Things will move fast. 1-2 months for 20km hop in Mk1. Next flight might just be orbital with booster/ship. Mk3 will start construction in 1 month. Building ships and boosters at Boca Chica and Florida as fast as possible. Improving design and manufacturing method exponentialy. Mk1/2 use plating Mk3+ single weld segments lighter and cheaper. Mk 2 expected in a couple of months, Mk3 in 3 months, Mk4 4-5 months. Reach orbit in 6 months.

54:08 Q) Crewed missions to leave from Boca Chica?
A) Yes 50/50 if it’s first to launch them.

55:09 Q) Flip manoeuvre and landing location?
A) Manoeuvre expected in Mk3/4 using hot gas thrusters. Methalox 300Isp easy even 350. Will land as per Star hopper location.

57:53 Q) Bridenstine criticism
A) < 5% of SpaceX resource used on Starship

59:49 Q) How to prevent boil off on interplanetary cruise?
A) Use a vacuum jacket. Header tanks inside main tanks, main tanks vented to vacuum so minimal boil off.
Q) How to minimise contamination?
A) Will be mitigated but some unavoidable. Low temp + UV will sterilize bacteria on the surface. Martian life if any expected to be under ground and robust. Mars and Earth already cross contaminated.

1:02:55 Q) What will Boca Chica look like in the future
A) A lot more buildings and stuff. Propellant production (LOX) will be needed, methane will eventually be synthesised as well.

1:06:21 Q) FAA approvals?
A) FAA good to work with. No fundamental obstacles. Offer made to buy out Boca Chica residents.

1:08:38 Q) What is SpaceX doing with 100 person Life Support systems?
A) Not seen as a problem.

1:10:22 Q) Superheavy development and timing
A) 2 Starships at each location before Superheavy due to Raptor demand 100 required before orbital flight Rate of production currently 1 every 8-10 days. 1 every 2 days in a few months and 1/day by end quarter 1 2020. Theoretically Ship can fly up to 4x/day and booster up to 20x/day

1:18:51 Q) Development time span of Stainless Starship?
A) 4-5 Months. Long is wrong, tight is right. Iterative process used.

1:21:18 Q) Tesla and boring machine on Mars?
A) Yes

1:22:29 Q) Engines required for boost back
A) 2 required for Super Heavy. Only gimbaled engines used. Entry burn to be avoided if possible, just landing burn.
IOW, Elon Musk's presentation seemingly filled with more immediate/tangible objects and goals casts the impression of getting a couple of steps up over the Jeff Bezos' robustly time-extended science fiction presentation.
Well, that didn't last long!

The Giant Crane returned to Boca Chica this morning and has been setting up. It appears to be getting ready to de-stack Starship, pulling its top and bottom halves apart again.

[Image: EF0kCFKWoAA74qQ?format=jpg&name=small]

Various opinions as to why...

1. Stacking was premature and only done to provide Elon (always a showman) with a giant prop for the cameras. Now the halves have to be pulled apart and completed. The canards/front fins don't look like a final installation and will probably be easier to work on closer to the ground. Or alternatively...

2. The fit between the top and bottom was so bad that they have to pull the thing apart, maybe cut a damaged ring off and try to refit the rest better. The problem looks to primarily be with the bottom edge of the top half, so cutting off a ring there will just shorten the empty cargo-crew compartment a little, and it isn't being used in this test vehicle.

https://twitter.com/NASASpaceflight/stat...0629932032

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

This photo shows the obvious dents around the line where the two halves are joined

[Image: EFlxV7YXoAAaxcD?format=jpg&name=small]
The bottom half has been placed on the Roll Lift crawlers and is headed back towards where it started the other day. Still isn't clear exactly where it will end up. On its original construction mounting? Or in Ironhenge, the big weather shelter where they can weld on it more easily?

Either way, it apparently still needs work before it's stacked for real.
Today the Giant Crane picked up the bottom half of Starship and placed it atop a circular mounting completed in the last few days from heavy steel I-beams.

https://twitter.com/BocaChicaGal/status/...0880999425

Not sure why. Maybe so that they can attach the landing legs.

They are preparing a similar mounting at Cocoa Florida too.

In other news, they are installing plumbing (pipes and stuff) atop the top tank bulkhead, the domed top of the bottom half. Kind of like we saw exposed with Hoppy, except with Starship the top half will go above it. So pretty clearly the vehicle wasn't exactly finished when they stacked it last week (for Elon's photo op).

Late yesterday, the top half was very carefully placed (by the Giant Crane) atop a fresh ring. Not sure if they cut a bent ring off and are replacing it, or what.

In Cocoa, something new that people are noting regarding all the extra rings they are accumulating (for the upcoming Florida Mark 4 prototype?) is that they are doubling some of them up, welding two together around their circumference to create rings twice as tall. I guess that they decided that it's easier to do on the ground than when the rings are stacked high in the air.

https://twitter.com/NASASpaceflight/stat...3351539713