https://ted2018.ted.com/speakers#gwynne-shotwellGwynne Shotwell at TED
Erik Cleven @VoltzCoreAudioReplying to @elonmusk and 3 othersHas the BFR/BFS been stretched in height? The video Gwynne showed at Ted Talks looks taller than the one in the E2E videoElon Musk ✔ @elonmuskMaybe a little 😉3:09 AM - Apr 13, 2018G C @SmileSimplifyReplying to @elonmusk and 2 othersWhich section/stage was stretched: 1st or 2nd or both stages?Erik Cleven @VoltzCoreAudioPossibly both according to this pic.twitter.com/VWR4L6Kpez3:27 AM - Apr 13, 2018
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?
If that stretch is around 20%, that could put Raptor above 2MN, 450klbf.That's a beast of an engine.
Quote from: AncientU on 04/13/2018 03:38 pmIf 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.
Erik Cleven @VoltzCoreAudioReplying to @elonmusk and 3 othersHas the BFR/BFS been stretched in height? The video Gwynne showed at Ted Talks looks taller than the one in the E2E videoElon Musk ✔ @elonmuskMaybe a little 😉3:09 AM - Apr 13, 2018
Quote from: docmordrid on 04/13/2018 10:58 amErik Cleven @VoltzCoreAudioReplying to @elonmusk and 3 othersHas the BFR/BFS been stretched in height? The video Gwynne showed at Ted Talks looks taller than the one in the E2E videoElon Musk ✔ @elonmuskMaybe a little 3:09 AM - Apr 13, 2018Here is a comparison between stills from the IAC Adelaide presentation and Jdeshetler's stabilised video. If there is a difference, it's very small.
Erik Cleven @VoltzCoreAudioReplying to @elonmusk and 3 othersHas the BFR/BFS been stretched in height? The video Gwynne showed at Ted Talks looks taller than the one in the E2E videoElon Musk ✔ @elonmuskMaybe a little 3:09 AM - Apr 13, 2018
I suspect from that tweet that it hasn’t stretched at all except perhaps some trivial amount
Under consideration. We’ve 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.
And speedevil is right... everyone was jazzed about the bigger fairing that ended up being ~2% larger.
Quote from: Lars-J on 04/14/2018 06:49 amAnd speedevil is right... everyone was jazzed about the bigger fairing that ended up being ~2% larger.I was totally jazzed by that 2% because it enabled my pet thought experiment mission which needed a payload envelope 4 inches wider than Fairing 1.0 allowed. Now that mission is only impossible for 2 reasons instead of 3. Woot! Slowly hurdling those obstacles.
Ok, I'll bite. What payload?
I had to look that one up.Low-Density Supersonic Decelerator (LDSD).
Quote from: FutureSpaceTourist on 04/12/2018 01:27 pmDifferent emphasis in this report on Gwynne's talk:QuoteAt the 2018 TED Conference on Wednesday, SpaceX president Gwynne Shotwell seemed for the first time to express an even grander vision than Elon Musk's plan to colonize Mars.Speaking to the crowd, Shotwell said she won't be content to land a SpaceX rocket on Mars, or even to reach more distant planets like Saturn or Pluto. Instead, she revealed that she ultimately hopes to meet up with whoever's out there in other solar systems."This is the first time I might out-vision Elon," she said of the SpaceX founder. http://uk.businessinsider.com/spacex-president-gwynne-shotwell-ted-mars-is-a-fixer-upper-2018-4Gwynne has in past talks mentioned her dreams of a future where travel to other solar systems is possible.
Different emphasis in this report on Gwynne's talk:QuoteAt the 2018 TED Conference on Wednesday, SpaceX president Gwynne Shotwell seemed for the first time to express an even grander vision than Elon Musk's plan to colonize Mars.Speaking to the crowd, Shotwell said she won't be content to land a SpaceX rocket on Mars, or even to reach more distant planets like Saturn or Pluto. Instead, she revealed that she ultimately hopes to meet up with whoever's out there in other solar systems."This is the first time I might out-vision Elon," she said of the SpaceX founder. http://uk.businessinsider.com/spacex-president-gwynne-shotwell-ted-mars-is-a-fixer-upper-2018-4
At the 2018 TED Conference on Wednesday, SpaceX president Gwynne Shotwell seemed for the first time to express an even grander vision than Elon Musk's plan to colonize Mars.Speaking to the crowd, Shotwell said she won't be content to land a SpaceX rocket on Mars, or even to reach more distant planets like Saturn or Pluto. Instead, she revealed that she ultimately hopes to meet up with whoever's out there in other solar systems."This is the first time I might out-vision Elon," she said of the SpaceX founder.
Some new images of @SpaceX's Big Falcon Rocket (BFR) from SpaceX president&COO Gwynne Shotwell's presentation at #TED2018 conference here: http://www.humanmars.net/2018/04/spacex-big-falcon-rocket-launch-images.html
Quote from: deruch on 04/12/2018 02:13 pmQuote from: FutureSpaceTourist on 04/12/2018 01:27 pmDifferent emphasis in this report on Gwynne's talk:QuoteAt the 2018 TED Conference on Wednesday, SpaceX president Gwynne Shotwell seemed for the first time to express an even grander vision than Elon Musk's plan to colonize Mars.Speaking to the crowd, Shotwell said she won't be content to land a SpaceX rocket on Mars, or even to reach more distant planets like Saturn or Pluto. Instead, she revealed that she ultimately hopes to meet up with whoever's out there in other solar systems."This is the first time I might out-vision Elon," she said of the SpaceX founder. http://uk.businessinsider.com/spacex-president-gwynne-shotwell-ted-mars-is-a-fixer-upper-2018-4Gwynne has in past talks mentioned her dreams of a future where travel to other solar systems is possible. This aspect of the TED talk seems a bit less off-the-wall in the context of the upcoming TESS launch.
there was a panel discussion that she was involved in, 2015/16 time frame, when they were asked for their predictions 25 years out... her answer was out of the norm... she said, "I hope by then we are working on Interstellar Propulsion" presumably she meant SpaceX, as none of the other participants were anywhere near that optimistic or forward thinking... that really stuck with me, because she just sat there, with a 'like what did i say that's so unusual' look...
Physically not impossible but way, way, way out of the current engineering capabilities.
Didn't someone say that Shotwell's video would be released today (the 16th)? I can't find it.
Quote from: cro-magnon gramps on 04/16/2018 09:07 amthere was a panel discussion that she was involved in, 2015/16 time frame, when they were asked for their predictions 25 years out... her answer was out of the norm... she said, "I hope by then we are working on Interstellar Propulsion" presumably she meant SpaceX, as none of the other participants were anywhere near that optimistic or forward thinking... that really stuck with me, because she just sat there, with a 'like what did i say that's so unusual' look... I remember that well. I argues at the time that she doesnt understand what she is talking about. Talking about going to other stars is too much of a stretch.Imagine its 3000BC, the local government at the Neil river just funded a new type of vehicle called a raft that can go over the Neil river to the other shore. It was a huge success and 50 years later, the first private company of raft builders offers regular service to transport goods over the Neil river. The local press interviews the guy who does it and asks where he sees river rafting in the next 25 years. Then he comes up with the answer that he hopes to work on rafts that swim the large darkness in order to visit the moon. Fast forward to today. We just are about able to get people to the moon. But going to another solar system is the same as our little raft builder going to the moon. Physically not impossible but way, way, way out of the current engineering capabilities.
Quote from: Semmel on 04/16/2018 09:43 amQuote from: cro-magnon gramps on 04/16/2018 09:07 amthere was a panel discussion that she was involved in, 2015/16 time frame, when they were asked for their predictions 25 years out... her answer was out of the norm... she said, "I hope by then we are working on Interstellar Propulsion" presumably she meant SpaceX, as none of the other participants were anywhere near that optimistic or forward thinking... that really stuck with me, because she just sat there, with a 'like what did i say that's so unusual' look... I remember that well. I argues at the time that she doesnt understand what she is talking about. Talking about going to other stars is too much of a stretch.... snip ...Physically not impossible but way, way, way out of the current engineering capabilities."Working on" doesn't mean "implementing". I see that as an area of research that she hopes by then they can be investigating, not promising an imminent mission.
Quote from: cro-magnon gramps on 04/16/2018 09:07 amthere was a panel discussion that she was involved in, 2015/16 time frame, when they were asked for their predictions 25 years out... her answer was out of the norm... she said, "I hope by then we are working on Interstellar Propulsion" presumably she meant SpaceX, as none of the other participants were anywhere near that optimistic or forward thinking... that really stuck with me, because she just sat there, with a 'like what did i say that's so unusual' look... I remember that well. I argues at the time that she doesnt understand what she is talking about. Talking about going to other stars is too much of a stretch.... snip ...Physically not impossible but way, way, way out of the current engineering capabilities.
Sorry if this is off-topic, but does anbody have a link to the TedTalk?
Quote from: richie2k3 on 04/17/2018 01:37 pmSorry if this is off-topic, but does anbody have a link to the TedTalk? As mentioned upthread - but it's $25 to access.
Sorry i missed this - are they usally chargable? I thought TED was 'Not for profit' --- for the greater good' etc...
I see Gwynne's interstellar remark as both a glib throw away and a personal fantasy but known to her, an engineer, as being fantasy.
Quote from: philw1776 on 04/16/2018 06:24 pmI see Gwynne's interstellar remark as both a glib throw away and a personal fantasy but known to her, an engineer, as being fantasy.I see it as vision.Like most things, it will boil down to economics. Once they're flying thousands of people to Mars on a regular basis, building a massive interstellar ship may not be that much of a stretch.The problem will be volunteers. At least initially, you'll need people that are willing to spend their entire life on the ship, and have their offspring be the ones to explore other solar systems. So the ship will need to be the size of a small city, something like a modern cruise ship, assembled in space. Something big enough, and with enough other people that it would be comfortable to spend a lifetime there.After Mars has been settled, I see that as the next big thing.And with a huge fully reusable launcher, it may not be fantasy. Remember, BFR will cost less to launch than Falcon 1.
"Not for profit" doesn't mean free. It means lowest possible cost. I am sure they have lots of expenses to cover.
Quote from: richie2k3 on 04/17/2018 02:03 pmSorry i missed this - are they usally chargable? I thought TED was 'Not for profit' --- for the greater good' etc... "Not for profit" doesn't mean free. It means lowest possible cost. I am sure they have lots of expenses to cover.
I have never had to pay to watch a TED talk - ever. Is this new?
How does TED make money?TED makes money through conference attendance fees, sponsorships, foundation support, licensing fees and book sales, and we spend it as soon as we get it — on video editing, web development and hosting for TED Talks and TED-Ed videos (ideas are free, but bandwidth is expensive…); support for community-driven initiatives like TEDx and the TED Fellows, and of course, paying fair salaries to staffers and interns.Everyone who buys a pass to attend a TED conference is helping share free TED Talks video with the world, as well as supporting the TEDx program, the TED Prize, free TED Fellowships, TED-Ed video lessons and more great stuff that is shared with the world for free. For this reason, a percentage of the attendance fee is a charitable contribution.TED Talks on the web are also supported by partnerships with carefully selected organizations; their ads on the videos and website support making TED Talks available to the world for free in many languages and on many platforms. We are very selective in the organizations we partner with. Other projects and initiatives are supported by foundation funding and individual donors.And of course we're also supported in kind by tens of thousands of volunteers — like all the amazing translators with the Open Translation Project, TEDx organizers, TED.com conversation moderators, organizations and individuals that support the TED Prize, and everyone who ever shares a TED Talk with someone else. (Thank you!)
SpaceX so far as we know is an engineering firm, not a basic technology R&D firm.
Quote from: Dave G on 04/17/2018 08:04 pmAnd with a huge fully reusable launcher, it may not be fantasy. Remember, BFR will cost less to launch than Falcon 1.Only if it comes back. If it's heading out into the void, it'll be nice and pricey.
And with a huge fully reusable launcher, it may not be fantasy. Remember, BFR will cost less to launch than Falcon 1.
SpaceX so far as we know is an engineering firm, not a basic technology R&D firm.Everything built so far including to-be-built BFR is based on engineering; it's not new R&D like interstellar propulsion would be. Not even exotic interplanetary propulsion. SpaceX does push and extend the state of the art (engineering) more aggressively than their stolid aerospace competitors or NASA. Rockets landing on their tails, carbon composite all extensions of what's been done but taken aggressively to another level that the timid eschew.I see Gwynne's interstellar remark as both a glib throw away and a personal fantasy but known to her, an engineer, as being fantasy.
Quote from: llanitedave on 04/17/2018 08:28 pmQuote from: Dave G on 04/17/2018 08:04 pmAnd with a huge fully reusable launcher, it may not be fantasy. Remember, BFR will cost less to launch than Falcon 1.Only if it comes back. If it's heading out into the void, it'll be nice and pricey.Unless you've invented a magic drive that can take a BFS to the stars from LEO, BFS once you get about 10km/s from earth isn't what you want to use, and even very cheap solutions dramatically outperform it.Getting BFS back is cheap, with perhaps the exception of if you're going to try a large gravity well manoever right next to jupiter.Any semi-plausible interstellar precursor mission is not going to be dragging along 85 tons of dead weight.For example, assuming BFS is $100M and launch cost to spacex is $10/kg as implied by P2P. With $100M, you can launch ten thousand tons of simple balloon tanks and engines capable of throwing 2 tons to 30km/s.
Quote from: llanitedave on 04/17/2018 08:28 pmQuote from: Dave G on 04/17/2018 08:04 pmAnd with a huge fully reusable launcher, it may not be fantasy. Remember, BFR will cost less to launch than Falcon 1.Only if it comes back. If it's heading out into the void, it'll be nice and pricey.Unless you've invented a magic drive that can take a BFS to the stars from LEO, BFS once you get about 10km/s from earth isn't what you want to use, and even very cheap solutions dramatically outperform it.
Quote from: speedevil on 04/18/2018 12:17 pmQuote from: llanitedave on 04/17/2018 08:28 pmQuote from: Dave G on 04/17/2018 08:04 pmAnd with a huge fully reusable launcher, it may not be fantasy. Remember, BFR will cost less to launch than Falcon 1.Only if it comes back. If it's heading out into the void, it'll be nice and pricey.Unless you've invented a magic drive that can take a BFS to the stars from LEO, BFS once you get about 10km/s from earth isn't what you want to use, and even very cheap solutions dramatically outperform it.I think BFS is way too small for interstellar travel. I'm talking about something that can carry thousands of passengers, with artificial gravity, and with enough space to manufacture some things on board. Basically a small city. Something people could live on for decades.Remember, once BFR is flying regularly, cost per BFR launch will be less than Falcon 1, i.e. less than $7 million per BFR launch, and each launch will get 150 tons to LEO.So for example, if it took 50 BFR launches to get the interstellar ship and propellant into LEO, total launch costs would be $350 million.As I said before, it all boils down to economics, and BFR is a total game-changer here.So when Gwynne talks about interstellar travel, I suspect shes thinking how it may work economically using BFR.
Quote from: Dave G on 04/19/2018 12:11 amQuote from: speedevil on 04/18/2018 12:17 pmQuote from: llanitedave on 04/17/2018 08:28 pmQuote from: Dave G on 04/17/2018 08:04 pmAnd with a huge fully reusable launcher, it may not be fantasy. Remember, BFR will cost less to launch than Falcon 1.Only if it comes back. If it's heading out into the void, it'll be nice and pricey.Unless you've invented a magic drive that can take a BFS to the stars from LEO, BFS once you get about 10km/s from earth isn't what you want to use, and even very cheap solutions dramatically outperform it.I think BFS is way too small for interstellar travel. I'm talking about something that can carry thousands of passengers, with artificial gravity, and with enough space to manufacture some things on board. Basically a small city. Something people could live on for decades.Remember, once BFR is flying regularly, cost per BFR launch will be less than Falcon 1, i.e. less than $7 million per BFR launch, and each launch will get 150 tons to LEO.So for example, if it took 50 BFR launches to get the interstellar ship and propellant into LEO, total launch costs would be $350 million.As I said before, it all boils down to economics, and BFR is a total game-changer here.So when Gwynne talks about interstellar travel, I suspect shes thinking how it may work economically using BFR.I believe she's serious, not joking... but BFR is not the ship for it. Unmanned probes would be first, and in 10 or 15 years the company "Planetary Resources" will be beginning to mine asteroids, the first production of steel on Mars will be underway, and Space Exploration technologies Corporation, a $200Bn enterprise will be working out how to mass produce tokomak fusion reactors light enough to put in ships. Its one thing journeying for a couple of years in space... but if its a twenty year journey, either it will be a ship like a city, with careers.. children ... a mobile space city, or most crew will be in hibernation. And any large ship will be built in orbit, with the main Mass becoming less likely to come from Earth. In my opinion...
Gwynne didn't say BFS would be for actual interstellar travel.But I think BFS is about the right size. You'd want the crew hibernating for the vast majority of the time, even for, say, 80% c travel (although 10% c is FAR more realistic). That makes it orders of magnitude easier to build.
You'd want the crew hibernating for the vast majority of the time, even for, say, 80% c travel (although 10% c is FAR more realistic).
We are quickly leaving the realm of sensible engineering here. Interstellar travel is outside our current and foreseeable future engineering capabilities.
Quote from: Semmel on 04/19/2018 10:58 amWe are quickly leaving the realm of sensible engineering here. Interstellar travel is outside our current and foreseeable future engineering capabilities. Why?What technology do we lack to do what I described above?With traditional launch costs, yes, it wouldn't be sensible economically, but BFR changes that.
BFR is entirely irrelevant to vehicles going at 0.1c, as it adds nothing over the vehicle just starting in LEO.BFR can just about - with an insane amount of effort recoverably hit 20km/s. ( around a thousand tanker launches)
You're not hearing me. I'm not talking about using BFR for interstellar travel. I'm talking about BFR launch costs enabling interstellar travel. A BFR launch will only cost around $7 million, an each launch will get 150 tons to LEO. That works out to around $20/pound.
Quote from: Dave G on 04/19/2018 11:20 amYou're not hearing me. I'm not talking about using BFR for interstellar travel. I'm talking about BFR launch costs enabling interstellar travel. A BFR launch will only cost around $7 million, an each launch will get 150 tons to LEO. That works out to around $20/pound.The problem is that if you assume interstellar travel is plausible, most of the technologies involved are so far down the line, and have such large possibilities that they make at the very least BFR pricing entirely utterly irrelevant.It's essentially precisely the same as arguing that a cheaper mule wagon makes supersonic transport plausible.There is no meaningful difference between $100000/lb and $10/lb launch costs for interstellar travel with BFS, because it's simply not happening in the same time.
Quote from: Robotbeat on 04/19/2018 02:10 amGwynne didn't say BFS would be for actual interstellar travel.But I think BFS is about the right size. You'd want the crew hibernating for the vast majority of the time, even for, say, 80% c travel (although 10% c is FAR more realistic). That makes it orders of magnitude easier to build.BFS would not be large enough for the radiation shielding required to travel at 80%cIt also has perhaps enough room for supplies for one mouse. Not nearly big enough for human interstellar voyages.
Quote from: Robotbeat on 04/19/2018 02:10 amGwynne didn't say BFS would be for actual interstellar travel.But I think BFS is about the right size. You'd want the crew hibernating for the vast majority of the time, even for, say, 80% c travel (although 10% c is FAR more realistic). That makes it orders of magnitude easier to build.Better yet, send just the frozen head and grow a new body at the destination, with local resources.Still better, send a silicon copy that does not need life support and is happy to live in a low temperature vacuum.This kind of reduce-the-payload-mass engineering is (IMO, obviously) more enabling than improve-the-rocket engineering. Both will be required, but it makes little sense to design a star ship that will take many decades to get there, while the biology and computation that could dramatically reduce your payload is changing enormously on single-decade timescales.
Quote from: LouScheffer on 04/19/2018 12:27 pmThis kind of reduce-the-payload-mass engineering is (IMO, obviously) more enabling than improve-the-rocket engineering. Both will be required, but it makes little sense to design a star ship that will take many decades to get there, while the biology and computation that could dramatically reduce your payload is changing enormously on single-decade timescales.I think it’s an exaggeration to say biology has changed a lot in a decade.
This kind of reduce-the-payload-mass engineering is (IMO, obviously) more enabling than improve-the-rocket engineering. Both will be required, but it makes little sense to design a star ship that will take many decades to get there, while the biology and computation that could dramatically reduce your payload is changing enormously on single-decade timescales.
No, it really, really, really doesn't.BFR is entirely irrelevant to vehicles going at 0.1c, as it adds nothing over the vehicle just starting in LEO.BFR can just about - with an insane amount of effort recoverably hit 20km/s. ( around a thousand tanker launches)20km/s is 0.007% of the speed of light, not 10%.In order to get BFS in LEO to 10% of the speed of light, starting out at 1185 tons, and burning to 85 tons, the engines would need an ISP of 1.1 million seconds.If we imagine it is accellerating at 1m/s for one year, the initial required power is 10^20W.Or put in perhaps more familiar units, a little more than a hundred times the total energy release of all nuclear weapons ever detonated, every second, for a year.
The fission fragment rocket (basically a nuclear reactor where the fission products are directed out the back) is estimated to be capable of an Isp of 1 000 000secs. Fission products around 5-7% of C. Not easy to engineer, and the thrust is estimated to be in the Newton range (pretty good for most of these high Isp concepts) but it does not require any breakthroughs in theory.
And biological engineering today is like chip design in the 1970s.- there are huge advances to be made that are conceptually clear, but for which the required technology does not quite exist.
Quote from: LouScheffer on 04/19/2018 02:10 pm And biological engineering today is like chip design in the 1970s.- there are huge advances to be made that are conceptually clear, but for which the required technology does not quite exist.Totally agree. I have ridden the incredible semiconductor wave for over 30 years but the signsof plateauing are clearly there.I encouraged my daughters to go into bio engineering of all the sciences because that is whatseems will dominate massive technological change over the next 30 years.Beyond engines, mass fractions, and nuclear propulsion - the biggest problem is that man is*currently* entirely unsuited for space in countless ways. Improving the payload goes a longway in making the delivery vehicle more practical. This is true for colonising the solar systemand likely far more important for thinking of pushing beyond.
Totally agree. I have ridden the incredible semiconductor wave for over 30 years but the signsof plateauing are clearly there.
FFR is great for missions to Eris, unfortunately, the power density is quite small, meaning it accelerates very slowly and can push a comparably minimal amount of mass, and burnout happens quite early as the reactor runs out of energy.A million second-newton is a 20MW or so reactor.
Quote from: Dave G on 04/19/2018 11:20 amYou're not hearing me. I'm not talking about using BFR for interstellar travel. I'm talking about BFR launch costs enabling interstellar travel. A BFR launch will only cost around $7 million, an each launch will get 150 tons to LEO. That works out to around $20/pound.The problem is that if you assume interstellar travel is plausible, most of the technologies involved are so far down the line...
It seems, in the absence of evidence, forum threads diverge into off-topicness. Maybe we should stop here and wait for the video to become public before continuing. There is no point in discussing this any further. If you want to discuss interstellar travel...
Quote from: Robotbeat on 04/19/2018 01:11 pmQuote from: LouScheffer on 04/19/2018 12:27 pmThis kind of reduce-the-payload-mass engineering is (IMO, obviously) more enabling than improve-the-rocket engineering. Both will be required, but it makes little sense to design a star ship that will take many decades to get there, while the biology and computation that could dramatically reduce your payload is changing enormously on single-decade timescales.I think it’s an exaggeration to say biology has changed a lot in a decade. This statement makes me pretty sure you are not a biologist. Whole new techniques are being discovered almost daily. Gene editing techniques such as CRISPR/CAS9 makes the headlines, but there are many, many others. And biological engineering today is like chip design in the 1970s.- there are huge advances to be made that are conceptually clear, but for which the required technology does not quite exist.Take even a quick look at eLife or Frontiers in Neuroscience, and you will see a field that's changing at a boggling pace.
In the comments on that post on reddit some user point to a rumor about joint between NASA and Spacex:" He'll be fine as none of our missions are expected to be cut or restructured, we have two huge reveals next year too along with a joint phase with SpaceX."Source:https://np.reddit.com/r/space/comments/8dh1xv/jim_bridenstine_confirmed_as_new_director_of_nasa/dxnp9o3/If this is true this is very interesting.
Talk is now up on their website:https://www.ted.com/talks/gwynne_shotwell_spacex_s_plan_to_fly_you_across_the_globe_in_30_minutes?utm_campaign=tedspread&utm_medium=referral&utm_source=tedcomshare
Quote from: AndyE on 04/23/2018 03:28 pmTalk is now up on their website:https://www.ted.com/talks/gwynne_shotwell_spacex_s_plan_to_fly_you_across_the_globe_in_30_minutes?utm_campaign=tedspread&utm_medium=referral&utm_source=tedcomshareWatched it. Most interesting bit to me was explicit discussion of "Elon time" vs. "Gwen time" (which is more like when things actually happen in the real world) -- she acknowledged that the difference is typically a factor of two. But went on to say that point-to-point BFR flights will happen within ten years -- Gwen time. Also noted that Elon likes to shake things up, and said her job got a whole lot easier when she started thinking of it (in effect) as getting the company in the best possible shape for the next disruption.Aside from that, not much new to this audience; no new technical details.
She did let slip they are going to build a bigger BFR and try to reduce Mars transfer time
Quote from: niwax on 04/23/2018 05:57 pmShe did let slip they are going to build a bigger BFR and try to reduce Mars transfer timeThat has been known since the ITS reveal in 2016.
I’m not a biologist. Yet I am aware of these changes (and indeed, many are incredibly exciting), but few are relevant to interstellar travel in a way that couldn’t be sent to the ship while in transit.
Watched it. Most interesting bit to me was explicit discussion of "Elon time" vs. "Gwynne time" (which is more like when things actually happen in the real world) -- she acknowledged that the difference is typically a factor of two.
Better image quality did make it clear that the "new" BFS still has 2 engines.
In order to be able to land the BF Ship with an engine failure at the worst possible moment, you have to have multiple engines. The difficulty of deep throttling an engine increases in a non-linear way, so 2:1 is fairly easy, but a deep 5:1 is very hard. Granularity is also a big factor. If you just have two engines that do everything, the engine complexity is much higher and, if one fails, you've lost half your power. Btw, we modified the BFS design since IAC to add a third medium area ratio Raptor engine partly for that reason (lose only 1/3 thrust in engine out) and allow landings with higher payload mass for the Earth to Earth transport function.
Quote from: Robotbeat on 04/21/2018 02:17 amI’m not a biologist. Yet I am aware of these changes (and indeed, many are incredibly exciting), but few are relevant to interstellar travel in a way that couldn’t be sent to the ship while in transit.Wow. Never thought of that before.You are sort of suggesting that, once we've got the ability to "3D print" lab equipment and so forth that would be sufficient to assemble a human being from raw materials, that we just build a probe loaded with that "3D printer" and raw materials, and fire that on a 1000-year journey to various stars.While it's on the way, we'll develop the technology for whatever we'll want to have when it gets there, and then send it the plans. If we want to have people out there to explore the new system, it'll print those too.I'd never thought of that before. Seems like an interesting Sci Fi story concept. The protagonist wakes up in a probe ship 10 lifetimes' journey from the nearest other person....
Quote from: rakaydos on 04/23/2018 05:58 pmBetter image quality did make it clear that the "new" BFS still has 2 engines.I believe that's the same video from last September.Since then, Elon said said it will have 3 engines. Specifically:https://www.reddit.com/r/space/comments/76e79c/i_am_elon_musk_ask_me_anything_about_bfr/QuoteIn order to be able to land the BF Ship with an engine failure at the worst possible moment, you have to have multiple engines. The difficulty of deep throttling an engine increases in a non-linear way, so 2:1 is fairly easy, but a deep 5:1 is very hard. Granularity is also a big factor. If you just have two engines that do everything, the engine complexity is much higher and, if one fails, you've lost half your power. Btw, we modified the BFS design since IAC to add a third medium area ratio Raptor engine partly for that reason (lose only 1/3 thrust in engine out) and allow landings with higher payload mass for the Earth to Earth transport function.
Quote from: Dave G on 04/23/2018 09:52 pmQuote from: rakaydos on 04/23/2018 05:58 pmBetter image quality did make it clear that the "new" BFS still has 2 engines.I believe that's the same video from last September.Since then, Elon said said it will have 3 engines. Specifically:https://www.reddit.com/r/space/comments/76e79c/i_am_elon_musk_ask_me_anything_about_bfr/QuoteIn order to be able to land the BF Ship with an engine failure at the worst possible moment, you have to have multiple engines. The difficulty of deep throttling an engine increases in a non-linear way, so 2:1 is fairly easy, but a deep 5:1 is very hard. Granularity is also a big factor. If you just have two engines that do everything, the engine complexity is much higher and, if one fails, you've lost half your power. Btw, we modified the BFS design since IAC to add a third medium area ratio Raptor engine partly for that reason (lose only 1/3 thrust in engine out) and allow landings with higher payload mass for the Earth to Earth transport function.100% not the same video. Only video released in 2017 was the Earth-to-Earth transport video, while the BFR vid shown at TED2018 is a shot-for-shot remake of the 2016 ITS reveal, just with the 3D models swapped. Presumably technically inaccurate in its inclusion of only two SL Raptors.
Or the 3 SLR design was considered and rejected in the last 6 months...
Quote from: rakaydos on 04/24/2018 01:14 amOr the 3 SLR design was considered and rejected in the last 6 months...One possible reason for this would be that Raptor development is going better than expected. If Raptor can run at a higher chamber pressure (more than the 250 bar that was stated at 2017 IAC) then the two sea level raptors have more thrust and more margin.
Quote from: vaporcobra on 04/23/2018 11:28 pmQuote from: Dave G on 04/23/2018 09:52 pmQuote from: rakaydos on 04/23/2018 05:58 pmBetter image quality did make it clear that the "new" BFS still has 2 engines.I believe that's the same video from last September.Since then, Elon said said it will have 3 engines. Specifically:https://www.reddit.com/r/space/comments/76e79c/i_am_elon_musk_ask_me_anything_about_bfr/QuoteIn order to be able to land the BF Ship with an engine failure at the worst possible moment, you have to have multiple engines. The difficulty of deep throttling an engine increases in a non-linear way, so 2:1 is fairly easy, but a deep 5:1 is very hard. Granularity is also a big factor. If you just have two engines that do everything, the engine complexity is much higher and, if one fails, you've lost half your power. Btw, we modified the BFS design since IAC to add a third medium area ratio Raptor engine partly for that reason (lose only 1/3 thrust in engine out) and allow landings with higher payload mass for the Earth to Earth transport function.100% not the same video. Only video released in 2017 was the Earth-to-Earth transport video, while the BFR vid shown at TED2018 is a shot-for-shot remake of the 2016 ITS reveal, just with the 3D models swapped. Presumably technically inaccurate in its inclusion of only two SL Raptors.Or the 3 SLR design was considered and rejected in the last 6 months...
Did we already know that BFR would have an 8 meter fairing? That was new info to me, although not surprising.
Still, it's going to be a far larger fairing space compared to anything that's flown in the past and should really open the doors to some cool satellites and large telescopes in the future - not to mention bulk satellite deployments on a scale that make what SpaceX currently does with IridiumNext seem small...
Quote from: rakaydos on 04/24/2018 01:14 amOr the 3 SLR design was considered and rejected in the last 6 months...Yeah, since Elon has noted that BFR has been stretched a little bit, perhaps the potential up-rating of the Raptor engine has allowed them to skip that 3rd engine on BFS after all.. Or, quite possibly it was a very quick editing job in terms of replacing BFR 3d models with the old ITS video and that it's not completely accurate as to the exact layout of BFR/S...
Quote from: Inoeth on 04/24/2018 01:31 amQuote from: rakaydos on 04/24/2018 01:14 amOr the 3 SLR design was considered and rejected in the last 6 months...Yeah, since Elon has noted that BFR has been stretched a little bit, perhaps the potential up-rating of the Raptor engine has allowed them to skip that 3rd engine on BFS after all.. Or, quite possibly it was a very quick editing job in terms of replacing BFR 3d models with the old ITS video and that it's not completely accurate as to the exact layout of BFR/S...As far as I remember Musk walked back to two SLRs earlier this year, but I cannot find my old comment with the reference. Maybe it was in one of the several interviews when Falcon Heavy went up, so it was little noticed?But what was news for me was that the propellant feeds have moved for the second time, to the outside of the engine compartment/hull.
A question concerning BFS SSTO: How would that work with only two SL raptors? Wikipedia currently lists SL at 1700kN and Vac at 1900kN. Two SL Raptors on a 1185t fueled BFS would give barely a 0.29 TWR, even if the vacuum engines could be run at full thrust in the atmosphere it'd only get up to 0.95 TWR.
Quote from: Torbjorn Larsson, OM on 04/24/2018 10:05 pmBut what was news for me was that the propellant feeds have moved for the second time, to the outside of the engine compartment/hull.Pretty sure those are legs.
But what was news for me was that the propellant feeds have moved for the second time, to the outside of the engine compartment/hull.
When Elon first mentioned BFS tests with orbital speed, he said it would require the vac engines. They can be fired at SL with full thrust.
"The "vacuum" or high area ratio Raptors can operate at full thrust at sea level. Not recommended."
Gwynne mentioned the diameter of the fairing being 8 meters for BFR allowing very large sats. Has the BFR stack shrunk in diameter since 2017?
SpaceX showed pictures of BFS's landed in exotic locations like asteroids or Jupiter's moons. Those would be very hard to get back. If they fueled in Mars orbit, they could send a probe with another propulsion module off to a much faster trip outbound, but we're still talking about a trip beyond its designed capabilities.
Quote from: Darkseraph on 04/26/2018 10:51 amGwynne mentioned the diameter of the fairing being 8 meters for BFR allowing very large sats. Has the BFR stack shrunk in diameter since 2017?More or less makes sense if it's interior vs exterior diameter.
Quote from: llanitedave on 04/18/2018 09:44 pmSpaceX showed pictures of BFS's landed in exotic locations like asteroids or Jupiter's moons. Those would be very hard to get back. If they fueled in Mars orbit, they could send a probe with another propulsion module off to a much faster trip outbound, but we're still talking about a trip beyond its designed capabilities.Hard to get back if you're doing a one shot. But that's the wrong way to think about this. Jupiter's moons are just another destination that needs infrastructure emplaced enroute. Stop thinking flags and footprints, and start thinking about transportation network extension, step by step. Railways managed to get all the way from Omaha to San Francisco, despite locomotives only being able to carry water for maybe 100 miles of travel and fuel for 2-300. At most. It was done incrementally. As the track was extended, gangs followed behind building wells, dams, water tanks, coaling depots, maintenance facilities, crew lodging, freight depots, and all the rest. All the materials they couldn't ISRU (everything except maybe timbers and rocks and dirt) were brought along, and as facilities were built, it got easier and easier to bring more materials. (fan to mod transition) Also, the concept of interstellar is not off topic., She mentioned it. But detailed discussion of how to do it in general? Off topic beacuse we have lots of other threads.
I guess they plan to be able to fill the whole thing with propellant and launch in less than 2 hours.
Questioned about whether governments will allow it, she said it wouldn’t have seemed likely the USAF would allow F9 boosters to fly back to their property and this is 10 km off shore.
I've read sound propagates better over water. Are there any calculations on the acoustic pollution produced by a BFR 5-10km offshore a major city?
Quote from: AbuSimbel on 04/28/2018 01:09 pmI've read sound propagates better over water. Are there any calculations on the acoustic pollution produced by a BFR 5-10km offshore a major city?Yes it does propagate well. I am very familiar with the Isle of Shoals ~6 miles off the NH coast and city of Portsmouth. I would be seriously surprised if any commercial passenger launch site outside a major city, assuming any are ever built, is less than 10 miles or 16Km offshore. These are very big rockets.
Quote from: Ludus on 04/28/2018 05:28 amI guess they plan to be able to fill the whole thing with propellant and launch in less than 2 hours. The main phase of filling the propellant in F9 and launching takes under half an hour, with most completed in 15 minutes.It starts only about an hour and twenty minutes before launch.
Quote from: philw1776 on 04/28/2018 01:14 pmQuote from: AbuSimbel on 04/28/2018 01:09 pmI've read sound propagates better over water. Are there any calculations on the acoustic pollution produced by a BFR 5-10km offshore a major city?Yes it does propagate well. I am very familiar with the Isle of Shoals ~6 miles off the NH coast and city of Portsmouth. I would be seriously surprised if any commercial passenger launch site outside a major city, assuming any are ever built, is less than 10 miles or 16Km offshore. These are very big rockets.I wonder if there are sound suppression techniques that might apply to this situation. I understand that the water systems used at some pads are for this. If it’s a pad at sea there might be new approaches to suppressing sound in the direction of the city.
Sound travels well over water because it's a perfectly flat surface. Maybe some installation around the pad to deflect the sound waves slightly upwards?
The President and Chief Operating Officer of SpaceX said 5-10km offshore. She wouldn't have said that unless SpaceX had analyzed all aspects of the offshore pad at those distances, including sound.In the absence of any information, speculation is fine. It's part of what makes this a great forum.But when we have it straight from the horse's mouth, speculation otherwise seems pointless.
Quote from: niwax on 04/29/2018 12:57 pmSound travels well over water because it's a perfectly flat surface. Maybe some installation around the pad to deflect the sound waves slightly upwards?The rocket travels upwards too, quite a long way up. I can't think how you could shield from that.
A more mundane possibility: Asking about stuff that would happen 20/35/50 years from now is a bit ridiculous from Gwynnes perspective. She is responsible for the economic success of SpaceX. She has necessarily a horizon of maybe 5 years or some more in some long term development projects. From her perspective, talking about stuff that is 4 to 10 times her current time horizon, there is no way she can give a sensible answer. So she gives intentionally a ridiculous one.
If you're doing point-to-point transport using a highly reusable system and fuel that is produced via electrolysis (indirectly for methane), then the fuel energy costs ends up being a driver of the overall system costs.Besides the usual performance improvements like higher chamber pressure, thrust-to-weight, etc, that drives you to playing with mixture ratios and using hydrogen instead of methane. Again, if you're making the fuel electrically.Nuclear thermal only really helps much for high speed beyond-LEO orbits. Anything else just ends up being suboptimal, energy-wise.So although SpaceX has not pursued hydrogen for a while, I expect them to return to it eventually. And yeah, nuclear thermal probably, too, in order to reduce Mars transit times to below 40 days.
For earth surface to surface, Hydrogen suffers from bad mass ratios and, relatedly, higher atmospheric drag per unit fuel. On paper it appears to be best only because engine math doesnt include tank differences.
If you're doing point-to-point transport using a highly reusable system and fuel that is produced via electrolysis (indirectly for methane), then the fuel energy costs ends up being a driver of the overall system costs.
Re sonic booms, if BFS is used for suborbital P2P how much of a propellant reserve would it have coming down? It may alleviate strength of local booms by going subsonic some ways up.
Quote from: Semmel on 04/16/2018 02:20 pmA more mundane possibility: Asking about stuff that would happen 20/35/50 years from now is a bit ridiculous from Gwynnes perspective. She is responsible for the economic success of SpaceX. She has necessarily a horizon of maybe 5 years or some more in some long term development projects. From her perspective, talking about stuff that is 4 to 10 times her current time horizon, there is no way she can give a sensible answer. So she gives intentionally a ridiculous one.I live in LA and run across SpaceX people all the time, including propulsion types. I've had, and overheard, multiple conversations that imply, or flat out state, that these guys expect to be working on advanced propulsion as soon as they finish Raptor/BFR. Some were actually bored with Raptor development, which they think is not really that advanced of a propulsion concept. Just highly necessary, and better than anything else available.
So that's a range of 3.1 to 6.2 miles offshore. Previously, I'd speculated somewhere around 5 miles offshore, so that seems to be about right.
Quote from: Dave G on 04/28/2018 12:50 pmSo that's a range of 3.1 to 6.2 miles offshore. Previously, I'd speculated somewhere around 5 miles offshore, so that seems to be about right.One possible objection to the system operating near heavily populated areas would be noise. Sound travels a long distance over unobstructed water. It strikes me that the giant rocket could rattle windows at 5km.
Congruent with Tom Mueller's stated enthusiasm for nuclear propulsion.Not that it would be public but I long wondered if Musk shouldn't spend a few million here and there investing in longshot fusion startups applicable to spaceflight, q.v. those producing electricity directly.
Fusion is vaporware offtopic.
BFS would probably slow subsonic high enough and far enough away from the landing site that it wouldn't have a problematic sonic boom if it was approaching over water. It has a much better glide ratio and lower terminal velocity than the Falcon booster.
Quote from: envy887 on 04/30/2018 02:27 pmBFS would probably slow subsonic high enough and far enough away from the landing site that it wouldn't have a problematic sonic boom if it was approaching over water. It has a much better glide ratio and lower terminal velocity than the Falcon booster. Sounds like those wings will be getting a bit bigger.
Besides the usual performance improvements like <snip> and using hydrogen instead of methane. Again, if you're making the fuel electrically.So although SpaceX has not pursued hydrogen for a while, I expect them to return to it eventually.
Long term on-orbit storage is irrelevant for point-to-point transport. Also is a solvable problem.
Quote from: CapitalistOppressor on 04/30/2018 02:42 amI live in LA and run across SpaceX people all the time, including propulsion types. I've had, and overheard, multiple conversations that imply, or flat out state, that these guys expect to be working on advanced propulsion as soon as they finish Raptor/BFR. Some were actually bored with Raptor development, which they think is not really that advanced of a propulsion concept. Just highly necessary, and better than anything else available.Congruent with Tom Mueller's stated enthusiasm for nuclear propulsion.Not that it would be public but I long wondered if Musk shouldn't spend a few million here and there investing in longshot fusion startups applicable to spaceflight, q.v. those producing electricity directly.SpaceX is already into ion propulsion for its satellites. Problem with that tech is even huge cluster arrays of ion jets produce too little thrust for heavy manned ships to Mars.
I live in LA and run across SpaceX people all the time, including propulsion types. I've had, and overheard, multiple conversations that imply, or flat out state, that these guys expect to be working on advanced propulsion as soon as they finish Raptor/BFR. Some were actually bored with Raptor development, which they think is not really that advanced of a propulsion concept. Just highly necessary, and better than anything else available.
Quote from: Robotbeat on 04/30/2018 03:13 amBesides the usual performance improvements like <snip> and using hydrogen instead of methane. Again, if you're making the fuel electrically.So although SpaceX has not pursued hydrogen for a while, I expect them to return to it eventually.Quote from: Robotbeat on 04/30/2018 04:02 amLong term on-orbit storage is irrelevant for point-to-point transport. Also is a solvable problem.Hydrogen is doubtless a solvable problem. And every solution you come up with is not worth the added cost in dollars.The entire storage - transportation - loading - storing - design - fabrication - using chain gets meaningfully more expensive as soon as you introduce hydrogen to it.If I would expect to see that to become a near term reality I could bet a small amount of money on hydrogen never being competitive even if the cost of electrolysis and electricity goes so low electrolysed synthetic methane becomes cheaper than any and all natural gas. That in such a case your operations, safety and hardware all combined end up cheaper if you compare hydrogen against methane.Hydrogen is a solvable problem, at a higher ticket price per passenger seat mile.
Hydrogen is terrible for cars, but if you get high enough scale, it may make sense for things that can’t be easily electrified (like rockets). When the cost of fuel becomes dominant, then it should be considered.I like methane as a rocket fuel and it’s the best choice for BFR right now, but sorry if I’m not in the hydrogen-phobia cult.
Hydrogen on earth may make sense once we have started producing fuel from regenerative power sources or nuclear. Not as long as the source are fossil fuels. On Mars hydrogen will be produced as part of methane production. It is an easier step there, going outward.
But if you generate and distribute very near point of use, such as major space ports, then leakage and distribution cost is small.Hydrogen can make sense at large scale, not at small.
storage of hundreds of tons for only about an hour
The surface area to volume ratio is vastly different, and the state of matter (liquid vs gas) is also different. You have to recalculate.
It's not about hydrogen being a superior storage method,
it's that it has the fewest steps
and fewest losses
You're not storing the hydrogen for long.
When the cost of fuel becomes dominant, then it should be considered.
Quote from: Robotbeat on 05/05/2018 05:06 pmWhen the cost of fuel becomes dominant, then it should be considered.We still haven't even reached the point where a car costs less then it's lifetime fuel... I do admire the forward thinking though!
Quote from: Dave G on 04/29/2018 09:37 amThe President and Chief Operating Officer of SpaceX said 5-10km offshore. She wouldn't have said that unless SpaceX had analyzed all aspects of the offshore pad at those distances, including sound.In the absence of any information, speculation is fine. It's part of what makes this a great forum.But when we have it straight from the horse's mouth, speculation otherwise seems pointless.For example, many of us here speculated that BFR specs from horses mouth at IAC 2016 would change. They did. When far off plans meet reality, especially when they are not engineering constrained, but regulatory, they have an even greater risk of change. SpaceX statements are not stone tablets to be worshiped without question, but current plans subject to change over the many years before possible fruition. I had thought SpaceX was notable for its ability to change course on the fly to adapt to reality intrusions and opportunities previously unknown or not sufficiently vetted. I doubt that BFR P2P is sufficiently vetted as of 2017.