Author Topic: TED talk by Gwynne Shotwell  (Read 41445 times)

Offline Semmel

  • Full Member
  • ****
  • Posts: 1407
  • Germany
  • Liked: 1199
  • Likes Given: 3265
TED talk by Gwynne Shotwell
« on: 04/13/2018 10:40 AM »
The recent TED talk by Gwynne Shotwell is not available online just yet but we have still a lot of discussion about it, which is polluting the "upcoming talks" thread starting here:

https://ted2018.ted.com/speakers#gwynne-shotwell

Gwynne Shotwell at TED

This thread is for discussing the content of the talk.

edit: Video is now available:
https://www.ted.com/talks/gwynne_shotwell_spacex_s_plan_to_fly_you_across_the_globe_in_30_minutes
« Last Edit: 04/23/2018 06:45 PM by gongora »

Offline docmordrid

  • Senior Member
  • *****
  • Posts: 4824
  • Michigan
  • Liked: 1919
  • Likes Given: 1
Re: TED talk by Gwynne Shotwell
« Reply #1 on: 04/13/2018 10:58 AM »
Erik Cleven @VoltzCoreAudio
Replying to @elonmusk and 3 others
Has the BFR/BFS been stretched in height? The video Gwynne showed at Ted Talks looks taller than the one in the E2E video

Elon Musk ✔ @elonmusk
Maybe a little 😉
3:09 AM - Apr 13, 2018

G C @SmileSimplify
Replying to @elonmusk and 2 others
Which section/stage was stretched: 1st or 2nd or both stages?

Erik Cleven @VoltzCoreAudio
Possibly both according to this pic.twitter.com/VWR4L6Kpez
3:27 AM - Apr 13, 2018


Offline FlokiViking

  • Member
  • Posts: 16
  • Seattle, WA
  • Liked: 15
  • Likes Given: 38
Re: TED talk by Gwynne Shotwell
« Reply #2 on: 04/13/2018 02:33 PM »
From those pictures a bit hard to tell, but maybe a couple of other changes?
- relative size of wing at base of BFS looks a bit smaller
- BFS nose looks less bi-conic, more conical
If correct, could reflect significant refinement of control laws.
« Last Edit: 04/13/2018 02:37 PM by FlokiViking »

Offline DistantTemple

  • Full Member
  • **
  • Posts: 270
  • England
  • Liked: 154
  • Likes Given: 285
Re: TED talk by Gwynne Shotwell
« Reply #3 on: 04/13/2018 02:56 PM »
Elon "confirms" it... somewhat flexibly.

says "Maybe a little" as the last shown reply at the bottom.
« Last Edit: 04/13/2018 02:57 PM by DistantTemple »
We can always grow new new dendrites. Reach out and make connections and your world will burst with new insights. Then repose in consciousness.

Offline ZachF

  • Full Member
  • ****
  • Posts: 504
  • NH, USA, Earth
  • Liked: 398
  • Likes Given: 104
Re: TED talk by Gwynne Shotwell
« Reply #4 on: 04/13/2018 03:29 PM »
In order to stretch the length they'd need pretty much a corresponding increase in Raptor chamber pressure. (Provided everything else stays the same at least)

Perhaps Raptor development goes (or continues to go?) better than anticipated? 300 bar back on the table?
« Last Edit: 04/13/2018 03:32 PM by ZachF »

Offline AncientU

  • Senior Member
  • *****
  • Posts: 6206
  • Liked: 3984
  • Likes Given: 5503
Re: TED talk by Gwynne Shotwell
« Reply #5 on: 04/13/2018 03:38 PM »
If that stretch is around 20%, that could put Raptor above 2MN, 450klbf.
That's a beast of an engine.
"If we shared everything [we are working on] people would think we are insane!"
-- SpaceX friend of mlindner

Offline KSC Sage

  • Member
  • Full Member
  • ***
  • Posts: 347
  • Liked: 487
  • Likes Given: 9
Re: TED talk by Gwynne Shotwell
« Reply #6 on: 04/13/2018 03:50 PM »
Erik Cleven @VoltzCoreAudio
Replying to @elonmusk and 3 others
Has the BFR/BFS been stretched in height? The video Gwynne showed at Ted Talks looks taller than the one in the E2E video

Elon Musk ✔ @elonmusk
Maybe a little 😉
3:09 AM - Apr 13, 2018

G C @SmileSimplify
Replying to @elonmusk and 2 others
Which section/stage was stretched: 1st or 2nd or both stages?

Erik Cleven @VoltzCoreAudio
Possibly both according to this pic.twitter.com/VWR4L6Kpez
3:27 AM - Apr 13, 2018


Be careful not to read too much into those images.  It looks like the aspect ratio is off on those images which causes the BFR to looked stretched.  I doubt at this stage of the design the OML will change very much.

Re: TED talk by Gwynne Shotwell
« Reply #7 on: 04/13/2018 03:51 PM »
u/Intro24 on Reddit used an un-distorted image to get a better size comparison.

https://www.reddit.com/r/SpaceXLounge/comments/8bznue/bfr_2018_size_comparison/

Looks like its just taller than the Saturn V (Elon couldn't let that slide  ;)). Also to me it looks like the legs sit in a little tube that extends past the ship to the booster. My theory is that the pushers that will separate the stages sit inside the tubes that are on the booster and will push against the bottom of the legs, instead of having separate points like Falcon 9.

Thoughts?

Offline ZachF

  • Full Member
  • ****
  • Posts: 504
  • NH, USA, Earth
  • Liked: 398
  • Likes Given: 104
Re: TED talk by Gwynne Shotwell
« Reply #8 on: 04/13/2018 03:56 PM »
u/Intro24 on Reddit used an un-distorted image to get a better size comparison.

https://www.reddit.com/r/SpaceXLounge/comments/8bznue/bfr_2018_size_comparison/

Looks like its just taller than the Saturn V (Elon couldn't let that slide  ;)). Also to me it looks like the legs sit in a little tube that extends past the ship to the booster. My theory is that the pushers that will separate the stages sit inside the tubes that are on the booster and will push against the bottom of the legs, instead of having separate points like Falcon 9.

Thoughts?

One thing that's noticeably different is the orientation of the grid fins and the leg nacelles(?).
« Last Edit: 04/13/2018 04:13 PM by ZachF »

Offline Elmar Moelzer

  • Senior Member
  • *****
  • Posts: 3119
  • Liked: 570
  • Likes Given: 822
Re: TED talk by Gwynne Shotwell
« Reply #9 on: 04/13/2018 04:14 PM »
I don't think it has been stretched much. The video is completely distorted by the angle. So it is most likely just looking a bit squished.

Offline Jdeshetler

  • Full Member
  • ****
  • Posts: 627
  • Silicon Valley, CA
  • Liked: 1968
  • Likes Given: 1436
Re: TED talk by Gwynne Shotwell
« Reply #10 on: 04/13/2018 05:11 PM »
This stabilized video was crudely widened until the water tower was proportional correct.


Online DanielW

  • Full Member
  • ****
  • Posts: 477
  • L-22
  • Liked: 339
  • Likes Given: 62
Re: TED talk by Gwynne Shotwell
« Reply #11 on: 04/13/2018 06:52 PM »
u/Intro24 on Reddit used an un-distorted image to get a better size comparison.

https://www.reddit.com/r/SpaceXLounge/comments/8bznue/bfr_2018_size_comparison/

Looks like its just taller than the Saturn V (Elon couldn't let that slide  ;)). Also to me it looks like the legs sit in a little tube that extends past the ship to the booster. My theory is that the pushers that will separate the stages sit inside the tubes that are on the booster and will push against the bottom of the legs, instead of having separate points like Falcon 9.

Thoughts?

Just use the legs as the pushers? they need to be able to extend and retract reliably anyway.

Offline DJPledger

  • Full Member
  • ****
  • Posts: 452
  • Liked: 127
  • Likes Given: 2939
Re: TED talk by Gwynne Shotwell
« Reply #12 on: 04/13/2018 07:19 PM »
If that stretch is around 20%, that could put Raptor above 2MN, 450klbf.
That's a beast of an engine.
31 engines is not optimal packing density on the booster. There is room for improvement to the engine packing density and hence thrust density by either going with 37 (1,6,12,18) Raptors of the same physical size as the dev. raptor operating at 25MPa or higher or 19 (1,6,12) larger Raptors of c.3MN at SL operating at the same pressure. Using dev. raptor size for ship will allow for greater engine out capability by requiring more engines. Raptor may be easier to scale than 1st thought and can be produced in multiple sizes without too much cost and difficulty. Optimizing engine packing density on booster will allow for a stretch without having to increase Raptor Pc. Further booster stretching can of course be facilitated by increasing Raptor Pc. which is a long term goal.

Don't be surprised if the Raptor no. on the booster changes again in the next BFR update.

Offline philw1776

  • Full Member
  • ****
  • Posts: 1043
  • Seacoast NH
  • Liked: 635
  • Likes Given: 294
Re: TED talk by Gwynne Shotwell
« Reply #13 on: 04/13/2018 10:23 PM »
If that stretch is around 20%, that could put Raptor above 2MN, 450klbf.
That's a beast of an engine.
31 engines is not optimal packing density on the booster. There is room for improvement to the engine packing density and hence thrust density by either going with 37 (1,6,12,18) Raptors of the same physical size as the dev. raptor operating at 25MPa or higher or 19 (1,6,12) larger Raptors of c.3MN at SL operating at the same pressure. Using dev. raptor size for ship will allow for greater engine out capability by requiring more engines. Raptor may be easier to scale than 1st thought and can be produced in multiple sizes without too much cost and difficulty. Optimizing engine packing density on booster will allow for a stretch without having to increase Raptor Pc. Further booster stretching can of course be facilitated by increasing Raptor Pc. which is a long term goal.

Don't be surprised if the Raptor no. on the booster changes again in the next BFR update.

Could not agree more. I guessed correctly that Raptor would be upscaled in 2016 IAC and it was.  Missed the 2017 downscale.  It's a work in process but until development matures more, it's subject to spec change.
Then you have the SpaceX/Mueller DNA that greatly improves an engine for generations after first flight protos.
ďWhen it looks more like an alien dreadnought, thatís when you know youíve won.Ē

Offline OneSpeed

  • Full Member
  • ****
  • Posts: 622
  • Liked: 771
  • Likes Given: 624
Re: TED talk by Gwynne Shotwell
« Reply #14 on: 04/14/2018 12:46 AM »
Erik Cleven @VoltzCoreAudio
Replying to @elonmusk and 3 others
Has the BFR/BFS been stretched in height? The video Gwynne showed at Ted Talks looks taller than the one in the E2E video

Elon Musk ✔ @elonmusk
Maybe a little 😉
3:09 AM - Apr 13, 2018

Here is a comparison between stills from the IAC Adelaide presentation and Jdeshetler's stabilised video. If there is a difference, it's very small.

Offline DistantTemple

  • Full Member
  • **
  • Posts: 270
  • England
  • Liked: 154
  • Likes Given: 285
Re: TED talk by Gwynne Shotwell
« Reply #15 on: 04/14/2018 01:21 AM »
Erik Cleven @VoltzCoreAudio
Replying to @elonmusk and 3 others
Has the BFR/BFS been stretched in height? The video Gwynne showed at Ted Talks looks taller than the one in the E2E video

Elon Musk ✔ @elonmusk
Maybe a little
3:09 AM - Apr 13, 2018
Here is a comparison between stills from the IAC Adelaide presentation and Jdeshetler's stabilised video. If there is a difference, it's very small.
The height of the camera is different and in the right hand picture, and the perspective is different, the right tower appears closer to the camera than the BFR, whereas in the left one they are level. Thus with as you say a small difference, its not clear enough to make a determination. But as EM says, "Maybe a little" and that little probably just happens to make it the "Biggest Rocket Ever" with no qualification of "since the Satern V".... I bet he has stretched it, and he would absolutely know, and "Maybe a little" is him having fun.
« Last Edit: 04/14/2018 01:23 AM by DistantTemple »
We can always grow new new dendrites. Reach out and make connections and your world will burst with new insights. Then repose in consciousness.

Offline Elmar Moelzer

  • Senior Member
  • *****
  • Posts: 3119
  • Liked: 570
  • Likes Given: 822
Re: TED talk by Gwynne Shotwell
« Reply #16 on: 04/14/2018 02:55 AM »
If it was streched, then all the wings/bulges were stretched by about the same amount. I am not sure that that would actually happen. I still think that this was just an optical illusion caused by the perspective of the camera that filed the video of the screen.

Offline DigitalMan

  • Full Member
  • ****
  • Posts: 505
  • Liked: 79
  • Likes Given: 8
Re: TED talk by Gwynne Shotwell
« Reply #17 on: 04/14/2018 05:27 AM »
I suspect from that tweet that it hasnít stretched at all except perhaps some trivial amount

Offline speedevil

  • Senior Member
  • *****
  • Posts: 2297
  • Fife
  • Liked: 1139
  • Likes Given: 1271
Re: TED talk by Gwynne Shotwell
« Reply #18 on: 04/14/2018 06:42 AM »
I suspect from that tweet that it hasnít stretched at all except perhaps some trivial amount

I'm reminded of the tweet
Quote
Under consideration. Weíve already stretched the upper stage once. Easiest part of the rocket to change. Fairing 2, flying soon, also has a slightly larger diameter. Could make fairing much longer if need be & will if BFR takes longer than expected.

When it turned out to be 2.5% larger in diameter.
« Last Edit: 04/14/2018 06:44 AM by speedevil »

Offline Lars-J

  • Senior Member
  • *****
  • Posts: 4050
  • California
  • Liked: 3349
  • Likes Given: 2110
TED talk by Gwynne Shotwell
« Reply #19 on: 04/14/2018 06:49 AM »
I suspect from that tweet that it hasnít stretched at all except perhaps some trivial amount

Thatís my impression as well. People who are analyzing these terrible quality images and coming up with a much bigger BFS should stay away from image analysis.

And speedevil is right... everyone was jazzed about the bigger fairing that ended up being ~2% larger.
« Last Edit: 04/14/2018 06:51 AM by Lars-J »

Tags: