Looks like fun. I'd love to see the in-flight safety video!
"Make sure there's nothing in your pockets because we'll be hitting 3 Gees. If anything goes wrong, we're all probably toast."
I think this was just an interesting idea thrown out at the end of a talk that had much more interesting stuff, such as redirecting all of SpaceX's resources away from Falcon to build the BFR, and putting humans on Mars by a 2024 'aspirational goal'
Note that the Instagram post is a little misleading. “Full Fare economy” is not as cheap as you think, it’s more like what you would pay for business class. So, maybe $3k for a transatlantic flight.
It will have to do intercontinental cargo flights for a while before it can be FAA human certified. They'll probably need to invent whole new classes of safety requirements before it can take passengers.
To me this looked like it could be the key to the whole thing...
That is, the idea is that you build a high-speed airline with spaceports all over the world, refueled by huge solar arrays refining Ox and CH4 out of the air. Then it turns out your airliners, by virtue of the fact they are orbiters, can also launch satellites and go to Mars and other interplanetary destinations (where similar spaceport situations can be built).
The key to the whole thing is to make the second stage an orbiter big enough to do re-entry so the whole system is re-usable. Re-usable second stages are a giant pain, but if the secret is to get big, and that means you're kind of "accidentally" running an airliner, then perhaps SpaceX has found the right business model for commercial space flight in such high volume that things like going to Mars and asteroids and so forth are sort of on the cost order of chartering a private flight -- well within the reach of many organizations.
The primary purpose of the cabin crew in an airliner is to handle emergencies. When SHTF, they'll figure out the right course of action, open emergency exits, and get people outside.
I'm not sure if the BFR ship would have any emergency survivability. It looks to me like the sort of thing where the flight goes well or everybody dies. In which case, yes, no need for cabin crew!
(And to be clear, I have nothing against "goes well or everybody dies" as long as the probability of "goes well" is sufficiently high.)
An emergency landing on water followed by everyone exiting the vehicle and using their seat cushion as a flotation device seems like the obvious counterexample. That seems survivable enough (I bet that ship would float better than a 747) but you'd want people on hand to help everyone out.
The point is with a rocket, if you can't land at your original destination, you probably don't have the capability to safely land anywhere else. Maybe I'm overlooking a scenario you have in mind, but IMO you're looking at two classes of problems:
1) Problem during launch. There's been one successful use of a launch escape system in rocketry history[1], and such a system has never been developed for a shuttle type craft.
2) Problem after entering orbit. Cutting your orbital flight short isn't going to change the fact that you still have to survive re-entry stresses and have a working vertical landing system.
> 1) Problem during launch. There's been one successful use of a launch escape system in rocketry history[1], and such a system has never been developed for a shuttle type craft.
I'm not sure if you're aware, but this is a feature of the latest version of SpaceX's capsules. I'm sure it would exist for their larger vehicles.
edit: although I'm just not sure what you'd do during an abort with all that fuel that larger vehicle holds...
I'm not so sure. The Dragon 2 integrates a launch escape system by using the same engines that are also intended for propulsive landing (which is now probably off the table for good, but that was the idea). The BFR ship won't have near enough TWR when fully loaded for its landing engines to double as launch escape engines, and I see no evidence of any other engines.
The fact that the BFR ship serves as both second stage and capsule combined, whereas the Dragon 2 is just a capsule with a separate second stage to put it into orbit, makes the problem a lot harder. I bet that the system for the BFR will consist of "don't explode."
The reason seems to be a combination of NASA not being interested in propulsive landing (and they're funding most of Dragon 2) and deciding to go all-out on BFR instead of refining Dragon 2 further.
I can't come up with a scenario where the BFR ship would make an emergency water landing. (Of course, it could just be that I lack knowledge or imagination.) Airliners can do them because they glide, so water landings are a possibility after fuel exhaustion or engine failure. BFR won't glide well enough to land softly, so it would have to be a propulsive water landing. And if you can land propulsively in the water, surely you can land propulsively at the landing pad.
> if you can land propulsively in the water, surely you can land propulsively at the landing pad.
I think if you take off and you immediately find that one of the rocket motors isn't gimballing correctly, or something else looks off with the engines, it might be prudent to abort before building up a lot of velocity. (not to mention aborting before something explodes) It's certainly easier.
I don't think that's always going to be possible, but yeah, that's probably the first choice.
I imagine the most problematic abort in something like a NY to London flight would be if multiple engines fail several hundred miles out. All kinds of velocity in the wrong direction if you want to fly back, not enough thrust to maintain the proper trajectory towards the target. I think there are bound to be some scenarios where you can do a limping, powered landing (the vehicle probably only needs one or two working engines) but you have to do it downrange.
I'm not sure that the ship would be strong enough to withstand a water landing. It'll come down on its tail, and then it will (I think!) tip over, which will probably smash it to pieces.
Aborts also leave you with too much fuel on board, probably way too much fuel. You could burn it off with the engines, although you'd want to actually use it to reach your origin or destination if possible.
If you abort early, you can still reach the origin. If you abort late, you can still reach the destination on the remaining engines. So the pertinent question is: do these two regimes overlap, or is there a gap, and how big? I don't have the answers, and you may be right that there is one.
Emergencies are a good point. You can't wave off and try landing again if something is not right. If diversion inflight is even possible then the options would be extremely limited.
Aren't supersonic jets more affordable? I mean I know SpaceX is about changing the world, and I know SpaceX is about rockets, but in terms of market, I think having a new Concorde would better fit the idea of earth to earth travel.
I like how SpaceX innovates, but I think this is a "too soon", bad product idea because it will be too expensive at first, and supersonic jets would be a better competitor.
Although I have to admit I really like the disruptive way of "showing the way to the future" communication ad. But to be frank, I wonder if people at SpaceX are not full of zeal sometimes. One bigger problem for SpaceX might be "how to sell space to consumers, or make money with space?".
Maybe that is the reason NASA existed as a government agency, because there is no real, direct ROE with space exploration. In the end SpaceX might make money with wealthy people who can afford going to mars or the moon, but I doubt that many people would be interested if there is no financial gain (or maybe for the hell of it). Innovation from NASA research was shared or benefited the military.
I want SpaceX to endure and succeed but I really wonder about the money/market sides of it. It requires a lot of vision, which goes beyond the reality of capitalism.
The trouble with supersonic jets is that they aren't that fast, they're limited in where they can fly, and range is problematic because they're much less efficient than subsonic jets.
Concorde shaved about three hours off the trip between NYC and Paris or London. It burned ungodly amounts of fuel (two tons of fuel just taxiing to the runway), cost a ton, didn't have enough range for Pacific routes, couldn't fly transcontinental routes because of the sonic boom, and after all of that it only saved a few hours.
Of course, Concorde is old technology and it could be done a lot better now. But you'd still be saving a limited amount of time (roughly a factor of 2), burn more fuel, and be more limited in range compared to a traditional airliner.
BFR would have enough range to connect any two points on Earth. It would have no restrictions on overflight (although it would most definitely have restrictions on where it could launch and land). And it would save 10-20 hours over a direct subsonic flight.
Cost? Well, I don't know. Elon says it'll be pretty cheap, but I'm skeptical. However, given how much more capable it would be than a supersonic airliner, it might be worth a much greater cost. Part of the problem with Concorde is that it just didn't save that much time.
It’s a really good question. Supersonic jets were always heavily constrained due to noise pollution issues with the sonic boom. They weren’t allowed to fly over land at supersonic speeds, relegating them to trans-oceanic routes. Now yes this system will have such problems on launch, but as they go pretty much straight up out of the atmosphere compared to a jet, the vast majority of the journey is in space where that’s not a problem. Also supersonic jets had range restrictions preventing maximum use of their speed, while this thing can go literally anywhere on Earth. Finally the big killers with Concorde was recouping development costs and paying for ‘one-off’ spare parts, the costs were crippling. The BFR will (hopefully) exist anyway, so that’s not a factor.
In principle yes a supersonic airliner could be cheaper, but the noise pollution issue alone is one of those external factors that is a real killer. Now it’s quite possible this use of the BFR might run into issues like that of its own, but they’re likely to be different issues at least.
If people think supersonic jets are loud, they’re in for a treat with rockets. Anyone who’s ever witnessed a launch at KSC (I have) will probably say two things: it’s awesome, and it’s LOUD.
Not ear popping kind of loud, but VERY loud nonetheless, and you feel it too if you’re close enough. (Really recommend a viewing at the LC39 observation gantry, it’s awesome!) I was watching that video and kept thinking that platform isn’t far enough from inhabited land that people won’t go apeshit over how loud it is.
I want this future, and boy do I want to see a rocket launch again, but waking up to that nice sound of rocket fuel burning at 6.30am? Yeah, maybe no. :o)
Airplanes are much, much quieter than rockets though. If you haven't seen (and heard!) a launch in person, I understand this might be difficult to appreciate. Even 10 miles out isn't enough to be ignorable.
Also the light – a launch is very bright! During the daytime this wouldn't be such a big deal I guess, but a dawn/dusk/night launch would be very noticeable, even from 10 miles out.
After the Concord was built, NASA did some research into reducing sonic booms (the Shaped Sonic Boom Experiment) which showed you could modify the fuselage to reduce the noise shock by about 30%. This would have brought the Concord below the acceptable noise threshold. Unfortunately it was never built-out commercially and we now have legislation banning supersonic flight over land.
I think the key difference is if you're designing specifically for travel on earth then supersonic jets probably are much cheaper.
However, if you're designing for space and can allocate the R&D costs to space business units, you end up potentially developing something that has better marginal costs to transport people across the earth.
Basically, the R&D of building this is astronomically higher than the supersonic jet. But the (theoretical) promise is the marginal cost isn't that different. However, if you're already doing the R&D for other purposes, then you find yourself owning a system that's (potentially) better for global travel.
They're currently unavailable at any price. If you make a really wild speculation based on taking the price of the most expensive airliner Airbus or Boeing sells and extrapolating from there how much a supersonic one might cost, it's not obvious that the airliner is cheaper.
They have enough money to give building the first ever BFR a shot. If it turns out good and the reusability works, they can do a lot of contracts with it, like servicing ISS, and launching a new big space telescope. From there on the advantages and possibilities of having a reusable high payload system will be very clear, and with 3-4 of them, a moon base would already be possible. We'll see what happens but the plan looks solid at least.
Supersonic jets could - maybe - more affordable, but they are slower than rockets, and the value proposition is in speed.
I'd actually worry about crowding skies above the planet. A rocket flying with suborbital speed has arguably less means to avoid collision if the possibility is detected in flight. Also rockets will need to pass heights where lots of satellites, orbital debris and even charged particles can present some danger to flying objects.
Many transportation systems are built using funds from selling land acquired at very low prices and then sold at much higher prices, once the transportation system is in place. Trolley systems in LA in the 1920's or road systems for the famous American suburbs.
Land on Mars is for the taking at the moment. What people will pay to live there is not known yet, but will be in the millions for some.
There could be a velocity at which the difficulty of flying quickly in the atmosphere is greater than the difficulty of reaching orbit. High mach number flight is not exactly easy, and the hypersonic regime has proven elusive. The atmosphere is a really hostile place at high velocity and has a lot of the same issues as space flight in terms of heating and crew protection requirments.
I think if we measure the travel time from door to door the benefits of the fast rocket shrink in a relation to where is located.
With airplanes this is solved, by the big infrastructure ( cities sometimes have even 2-3 airports ).
Where I live ( Berlin ) with a flight to NYC would look like :
1. City center -> TXL - 20m
2. Check-in / security - 30m ( no joke, the airport is small )
3. Flight - 9h 15m
4. Check-out / luggage - 50m
5. EWR -> City center - 50m
------------- TOTAL ---- 11h 25m
This means that ( ignoring the BFR flight time, since it's just minutes ) the time between you leave the city-center and entering the BFR should take less than 5 hours ( for Berlin ), otherwise you will not arrive faster than a plane.
For a very high profile requirement - say, some kind of huge emergency - you could land the BFR anywhere there's a solid surface the size of a soccer field. Zero infrastructure required.
Getting it out of there again would be difficult, but you could have a team of experts and a whole lot of material resources literally drop down from the sky anywhere on Earth in a matter of hours. Most of that duration would be spent loading the human and material cargo into the rocket.
We have no way of doing that currently.
P.S.: And if the emergency is big enough, you could drop the whole thing into the ocean near the shore and just jettison the passengers and cargo shortly before impact.
Total Time is only one portion of the suckage of air travel though. It's that long window of time where you are cramped in a small seat, potentially with large strangers spilling into your space from either side that I dislike the most. If I only have to deal with that bit for 30 minutes, the rest of the trip can take as long as it reasonably wants.
No more deep vein thrombosis. Or screaming kids kicking the back of your chair cause they've got nothing to do for 10 hours. London to Sydney would be a massive improvement because often you have to stop halfway.
Plus you get all the benefits of paying for a Virgin Galactic trip
Hub and spoke model. I can't imagine being more than 5 spaceports per continent. Most popular destination from Auckland would be London. I don't mind taking Ryanair from there.
Hard to know how many would go at one shot. A few hundred? One could move cargo also. Maybe once a day? For a 40 minute trip, maybe a lot more. Depends on the price. The thing is, the infrastructure a rocket needs might be way less than big airplanes. Super chilled CH4 and O2 and a small pad and tower. Along with doing say 20 flights per day, these things can move around the globe easily and go where the demand is.
The reason the video shows a sea launch is that you can use a high-speed ferry to get to an empty area from the city center in less than an hour. Inland cities like Berlin aren't targeted.
I'm not sure here, but I think weather could play a major role in disrupting launches, greater than with jet liners, right? And not just due to windy conditions (which planes can better withstand up to a certain point), but also rough waters.
Another issue is noise. I don't see rockets happening that close to shore in large cities. A long pad-to-city commute, with ship trip included, would be another inconvenience.
Maybe. Rockets can actually fly through a variety of rough weather conditions. Indeed, they can even survive being struck by lightning (as Apollo 12 was). However, they are not, as a rule, designed to do so. And because they are multi-million dollar equipment that are only used once before being discarded it's easier to simply avoid launching in weather that might be too severe.
However, in practice a rocket could be designed to fly in much more severe weather than is allowed for most launches today, it just takes designing it to do so. Because of the huge cost of rockets today designing a rocket to fly through adverse weather would add additional additional manufacturing cost onto each launch, which is not a good tradeoff. But if you can ammortize that over many flights, then it's not a big deal.
Think about ICBMs and SLBMs. Do you think there is someone sitting in a Minuteman bunker looking at the weather, ready to tell the launch officers just after they've turned their keys "sorry fellas, I've overriden your orders, we can't launch today, the weather is too crummy, oh well, better wait until tomorrow, if there is one"? No, missiles are designed to launch on a moment's notice, and be capable of successfully hitting their targets even if the local weather is terrible. Their designed to be able to launch through thunderstorms and experience only a small percentage of losses in the most unusual conditions. Similarly, any orbital rocket can be designed to be able to launch through most typical severe weather events, with only a small percentage of conditions (compared to today) requiring a scrub because it would endanger mission success.
The degree to which SpaceX will do such a thing is unknown, but it's within the realm of possibility.
Also, it should be noted that a major reason weather has a historical role in disrupting launches is because one of the best locations for launches in the US (Florida: Easterly coast, as close to the equator as possible) is also one of the few places on Earth with the most thunderstorm activity (roughly one out of five days in Florida has a thunderstorm). The vast majority of other locations on Earth don't experience nearly the same level of launch-risk inducing severe weather.
ICBMs also typically launch from underground, which helps a bit with the noise and maybe even the weather. Also, you'd have to dig a pretty wide hole to make it land-able and reusable.
Presumably several ICBMs are launched at a particular destination at the same time; unlike a payload of paying passengers an ICBM's payload is somewhat fungible so more risks can be taken.
Punching through the atmosphere layer at speeds that are economical when every two extra minutes spent there waste more than one km/s of precious delta-v make every storm look tame. But solving the control problem for the "suicide burn" landing? I would not be so sure about that.
I don't think it's a suicide burn. The upper stage of the BFG has separate engines for vacuum (4) and atmosphere (2). The two atmospheric engines are only used for landing so, unlike the Falcon 9/Heavy, they can probably be throttled down far enough so the thrust equals the weight. The suborbital earth transport rocket (which is super hypothetical at this point) would presumably have these features too.
Another way to say this is that suborbital flight requires sufficiently less Delta v that you can afford to have engine diversity.
Given enough thrust even pigs can fly, so I'd say it's just a matter of more struts and much bigger RCS. Since we're talking suborbital, mass penalty isn't that bad.
First, instead of people, a great first market for this would be cargo. It would enable same-day delivery of goods anywhere in the world. Surely there's a market for that. I know for a lot of tech gear, when you need it, you need it right now. Factoring in the cost of a business-class ticket (per kilo), isn't anywhere near being a show-stopper.
Second, time-to-load could be a real factor, especially if you have to reach city center, then load into a boat, then go to the pad, then load in the rocket, then wait for fuel loading, etc. A better way to do this would be to use hyperloops in a spider fashion from the launch pad out to several of the burbs around the city. I could see the hyperloops ending underwater near the pad, with a nice mall and places for people to wait until their rocket was in position for flight. God help us, you'd still have the TSA nonsense.
Third, it just shows a barge, but this would be an entire "thing" -- launchers, rockets, fueling stations, malls, security, and so forth. Maybe cargo is a pretty good way to get started. Adding people just makes the complexity worse.
Fourth, before you do cargo, you could do a few high-profile people shots every month, for folks with lots of money who want to be remembered as some of the first folks to ever travel sub-orbitally. Hell if you'd want an accident in those days, though. Public relations will be a bear. It reminds me of the early days of flight, when most folks had a deep and profound fear of the machine. Do you want to get on to the top of a huge stick of dynamite? I do, and most HN'ers might, but a few YouTube explosions that kill people could shut the entire thing down (or worse, delay it for decades)
There are three things that would factor into my decision about whether to strap myself to a rocket rather than fly in a plane: time, cost, and safety.
Musk & SpaceX are talking a lot about time and cost, but safety is obviously a lot more important. Based on data I found on the internet (so it must be true!) the loss rate for rockets is 20k - 165k higher than the fatal crash rate for airplanes over the past 20 years.
Loss rate for manned rocket launches [1]: 0.79%
Loss rate for unmanned rocket launches [1]: 6.68%
Rate of airplane crashes with at least one fatality [2]: < 0.00004%
Even if SpaceX is able to make manned space flight 10x safer, I'm not sure I'd trade 19 of the 20 hours I spent traveling from LA to South Africa this summer for a 1/1,300 chance of blowing up during launch.
Loss rate for space launches is largely due to the fact that the systems are essentially munitions (i.e. expendable, single-use) and flight rates are very low.
Rocket failures for crewed rocket launches are extremely rare, occurring once every couple decades. It's hard to improve on that because low flight rates make data very hard to come by. Airplanes fail much more often in absolute terms, giving you a lot more data to work with (especially when combined with near-misses) allowing you bring the relative failure rate very low.
Increase flight rates by 5 orders of magnitude, and you may be able to increase reliability by, say, 4 orders of magnitude.
The problem is that to increase flight rates by 5 orders of magnitude, you need demand to increase by that much. And people are unlikely to demand rocket flights until after they're as safe as plane flights.
Early passenger planes were pretty dangerous to, but they got around the above problem by a) being much faster than trains, making the risk worth it, b) having clear military applications, the military being less worried about losing the occasional aircrew.
I don't really see how SpaceX gets around that chicken and egg problem.
They're going to get around it because this is a secondary market for BFR. Primary market is launching satellites (especially their constellation).
Remember, this point-to-point idea was basically an after-thought. It's decades away, but the rocket will be launching within the next 3-5 years. So they'll have decades to get it right, and the manufacturing line and much of the infrastructure will be paid for.
But you're right about demand. The biggest economic problem is that it's too big. Each BFR needs 1000 passengers. To be economic, it needs to fly multiple times per day, so each BFR needs to fly like a million people every year. Look around to how many people fly long-haul, and you saturate the existing market VERY quickly.
BUT the world is getting richer. Soon (50-80 years?), there will be 5-10 billion middle class folk in the world, an order of magnitude more than now. And if the time for travel can be cut short like this, then you should have some demand induction taking place. So maybe it'd start making economic sense.
There is a fundamental advantage for BFR versus existing aircraft: SpaceX is able to make Falcon 9s and probably BFRs for about the same cost (a little less, actually) per unit dry mass as a 737 or 777 or A380. But a BFR can do trips that'd last 15 hours in a 777 or A380 in less than 1 hour. That means you can do 10 times as many trips, cutting your amortization time and crew hours by an order of magnitude. But that depends on having enough demand, which is pretty questionable except in the long-term.
Total orbital rocket flights/yr are usually considerably less than 100 though, so I'm sceptical they'll ever approach airplane reliability with so few flights.
Honestly, that's kind of why the BFR idea kind of worries me. It feels like SpaceX analysed the need for orbital space-flights, and realized there was unlikely to ever be the kind demand that would provide the economies of scale needed to do what they want. On the otherhand, there's undeniably a large demand for terrestrial travel, so they came up with a way to use rockets for that purpose. It feels like something to show investors, rather than a workable plan.
But hopefully I'm wrong. Economics aside, its certainly cool, and it would be nice to have an application for terrestrial missiles other than nuclear annihilation.
"Total orbital rocket flights/yr are usually considerably less than 100 though, so I'm sceptical they'll ever approach airplane reliability with so few flights."
"with so few flights" is the operative phrase there.
Current launch market is about 60-100/year.
This is why SpaceX invented its constellation: not only does it allow them to make a lot more money than just doing a few dozen launches per year, but it allows them to generate their own demand for launches to justify these crazy Mars rockets. The constellation is for about 12,000 satellites replaced every 4 years or so. Initially 500kg, but Mueller (rocket guy) recently hinted they could get much larger (so let's say 50-100 tons). Therefore, they'll be able to self-generate between 30 and 3000 annual BFR launches on their own. This point to point thing is another add-on market, could be even larger from a launch volume perspective (but, interestingly, smaller from a addressable-market revenue perspective than the constellation). With 3000 flights per year and margin to spare (and the benefit of post-inspection of the rocket in case of a near-miss), you should be about 100-1000x as reliable as today's crewed rockets just to start. Now add point-to-point, and you can do 50,000 BFR flights per year...
You answered your own question: military applications.
The US Armed Forces would pay a LOT of money to move 100+ tons of personnel and materiel anywhere on earth with a flat landing spot in under 60 minutes.
You could have tanks on the ground that were fully operational in under 3 hours (probably half that if they left the BFR packed and fueled for takeoff at all times), or a disaster recovery base set up within 24 hours of the winds dying down (to pick a more topical example.)
Maybe, though the military has studied similar ideas before and nothing has ever come from it, so I'm sceptical they're going to throw the kind of funding at it that would be required here. As a general concern, actual travel time doesn't usually seem to be the main determinant of how fast military forces can be deployed.
But who knows. The idea of a big capsule coming down in a war zone and a bunch of tanks and marines rolling out certainly seems pretty cool, and I'm sure Musk and his lobbyists will at least try and convince the DoD that its something worth throwing a lot of $$ at.
Its not "anywhere on earth with a flat landing spot" if you want to be able to retrieve the thing. It either needs to go somewhere with the very specialized launch infrastructure and personnel it needs or the ability to transport (how to you transport a 48m x 12m cylinder?) it to somewhere that does.
Yea, but the main advantage of the system over air-travel is that it's fast. For most types of cargo, cost rather then speed is the main issue, especially if the difference is just on the scale of a few hours.
When shipping internationally if cost rather than speed is the concern you ship by boat. Shipping by rocket over a plane would just be another higher tier of service. If Musk's pricing is to be believed it would make shipping between continents potentially faster than shipping within the continent. That would change the industry.
The loss rate for manned space launches over the past 20 years has been 0.79%. What you're pointing out (only once every few decades) is a factor of the small number of manned launches per year. Actual loss rate is very high. 1/130 chance of loss.
Most (all?) of that rate provided by the shuttle program and by early vehicles from the 60s and 70s.
Mercury + Gemini + Apollo had a 0% death rate in-flight. Not that they didn't come very close.
The shuttle had numerous design flaws. The use of solid fuel. A booster that was assembled in seven different sections, fastened, and sealed with rubber o-rings. Go-fever. Foam insulation that was known to fall off and strike the orbiter during launch.
Not that space flight isn't dangerous. My point is we can do a lot better with proper designs and attitudes. SpaceX also gets to examine and improve their stages in a way that has never been possible now that they come back in one piece.
That you will always have at least single digit failures. Sometimes things have to go wrong before we can correct them. We got where we are today with airplanes not because the first million flights didn't have a single accident, but because we paid careful attention to every failure and did our best to keep it from ever happening again.
Take a look at this report on Boeing crash history: http://www.boeing.com/resources/boeingdotcom/company/about_b...
In particular, take a look at page 17 (slide 16) which shows the crash rate over time. We have gone from about 40 hull losses per million departures in the 50's to about 0.6 to 1 (depending on how you count) per million departures today.
I wonder how you constructed that comparison such that it seemed meaningful. I'm pretty sure the lesson when you look at the data would be "fly on a man-rated Soyuz, not a Space Shuttle."
Do you see that as an indictment of the safety of manned space flight, or the safety of that vehicle? (you do understand that the modern Soyuz is quite safe, right? One can expect SpaceX's stuff to be safer.)
Are you looking at failures per mission or fatalities per person-trip? I thought the shuttle and Soyuz were very close on the fatalities per person-trip metric.
I can't quickly find a source, but back of the envelope is there have been 134 Soyuz manned missions. The number of people varies 1-3, most often 3 but occasionally 2. There were 135 Shuttle manned missions. Number there varied between 2-7, but ballpark looks like 6 was common.
So if we say 3 x 134 on Soyuz, there are 402 person-trips and 6 x 135 on Shuttle it is 810 person-trips. There were 4 Soyuz fatalities and 14 on the shuttle. So Soyuz fatality rate is about 1/100 and the shuttle is 1/56. So maybe it is closer to a factor 2 of difference.
The fatal mission rate is nearly identical (both have 2 fatal missions each).
In the video, Musk states that SpaceX believes BFR will match the safety of commercial airliners due to its multi-engine propulsive landing capability.
Yes, totally, I get that they have a plan to make it safer -- my point is that a 20,000x increase in saftey is a massive leap, and that will be the limiting factor for this technology.
Oh, right. I don't disagree with your sentiment, I was just adding information for HNers who didn't actually watch the video.
Consistently, my colleagues have made remarks along the lines of "I'll take the 1,000th flight after I know it's safe enough". I grew up with cars and airliners so I'm not sure what the process of convincing the public of BFR's safety will actually look like or how long it will take. For all I know, they'll give out the first 100 rides for free or at huge discounts, making all of these thoughts moot.
Well, your comparison isn't too fair. It seems like you're using the loss rates for modern aircraft capabilities. This is roughly like comparing the crash rates of modern OS's to early Unix.
To put it another way, it seems likely that the safety will increase by that much. Before airplanes, hang gliders were one of the most popular ways to fly, along with balloons. Gliders were incredibly unsafe, because pilots were expected to control the glider by shifting their body weight. This made stalls fatal, since you couldn't recover.
Again, I'm not saying it's not possible I'm saying that it's going to be really, really hard and that saftey is the critical path to making this viable. I'm sure they are spending all of their time and resources devoted to improving saftey. I'm just pointing out the ridiculousness of focusing the PR on time savings and cost parity when the saftey deficit is currently massive.
Fair has nothing to do with it. Civilians aren't going to pay for tickets on a rocket that they perceive as unsafe just to save a few hours. Those rockets will have to go years carrying cargo (or maybe military personnel) with zero crashes before the FAA will be willing to certify them for carrying paying commercial passengers.
> There are three things that would factor into my decision about whether to strap myself to a rocket rather than fly in a plane: time, cost, and safety.
It's a valid concern, but it's only a matter of time before each new technology is perfected and made safe.
The exact same debates took place when Stephenson built his locomotive.
Reusability and greater frequency will change these calculations radically. Similar statements to yours were made about flight in early airplanes, which was also dangerous.
Not too get too off-topic with HN's strict rules, but here's an anime depiction of what I believe you to have been imagining: https://gfycat.com/gifs/detail/ActualFeistyBettong (sorry for the image macro, I couldn't find a HTML5 embed without it)
I had a vision of it diving inside the water and becoming some superfast submarine, perhaps cutting through the earth's crust or something. Anything can happen right!
Laptop manufacturers don't typically include 'maximum operating G' information. Looks like there's a freefall phase during the flight, though, during which a laptop with a physical hard drive would likely enter freefall protection mode. So you'll at least want to use an SSD.
Take off/landing are probably a big chunk of any 30min flight, so you'd really only have 15-30min at most being disconnected from your laptop or phone, not a big deal. I'd be totally satisfied just looking out the window... even on my 20th flight I doubt it'd be boring.
A built-in tablet that turns on automatically in each seat might solve this problem. But then someone will have to offer wireless internet in space.
You'll also be under significant g-forces or zero gravity for large parts of the flight. I, for one, would probably be preoccupied with myself, trying (and failing) not to puke all over the place. For the few minutes I don't stare into my vomit bag, I'd rather enjoy the incredible view out the window than a random excel sheet on my laptop.
I think that depends on whether or not the ticket is something like 50x more expensive.
If Musk is proposing this idea then I assume it won't be too expensive, even for rich people. So it should cost significantly less than what private jet trip costs them (because the BFR is not so private after all).
Of course, the faster time to destination should also balance things out, but I have a feeling a trip would be more like 2h with the boat trips and waiting time included, because as others have said, I doubt the launchpad will be that close to shore.
Latest claim:
"elonmusk Fly to most places on Earth in under 30 mins and anywhere in under 60. Cost per seat should be about the same as full fare economy in an aircraft. Forgot to mention that."
What's a NYC to SHA full fare one way, about $800? I wonder if he is also getting into the fuel business? So if this rocket holds 200 people, that only gives him $160k in revenue. Fuel for the smaller Falcon is more than that per launch. Or is this baseless hype?
In the presentation he mentions that the payload volume is larger than an A380, which seats 525 passengers in a standard configuration or over 800 passengers in an all-economy configuration.
So we're looking at more like $400-$600k revenue per launch. And honestly, if prices came in at 50% more than traditional airlines, you're looking at a hell of a great deal to cut your travel time dramatically.
So say we boost things to 1,000 passengers, cost of full fare is $5000 so people are willing to pay $10,000. Assume passengers and luggage average out to 200 lbs/passenger. You are looking at a revenue per launch of $50/lb. Sure, this is suborbital, but that is nearly 50x cheaper than what it costs to get to LEO using SpaceX right now.
You can't fly NYC to Shanghai on a private jet (unless it's a 777 or equivalent, which 99.9% of private jets aren't). This is a real game changer in aviation terms.
Why not instead work on ways to reduce the need to move people from one place on Earth to another, thereby eliminating the cost, hassle and pollution of air travel and hypothetical rocket travel? There's a huge amount of progress that can be made in telepresence technology--it seems silly to get hung up on the assumption that in order to do something or experience something somewhere you need your bag of water and meat to physically be there. We're very close to mass adopting remote employment--to the point where the barriers are no longer technical but cultural. Why not work on the same for other areas of business and for personal vacations? Physical travel should seem like a silly inefficiency!
We should focus on making the Holodeck, not rockets.
Why don't you start working on Holodecks. Musk wants to get humanity off this rock. Funding the building of a ship designed to land anywhere in the solar system, including Earth, by using it for Earth transport is brilliant. If one can make the trip from New York to Shanghai in 40 minutes, for the same fuel per person and ticket price as an airplane, why not. Having a fully reusable rocket will be amazing.
Once reliability is proven one could even start thinking about nuclear powered rockets and get those CO2 emissions to zero. I'm sure it is on Elon Musk's mind and Mueller has even mentioned looking into nuclear rockets. Solar system travel could really use nuclear rockets to get reasonable travel travel times.
I fully applaud efforts to "get humanity off the rock". To the extent that building a rocket airline helps move humanity toward this goal, great! But, other than as a stepping stone to something bigger, this just seems like a silly distraction.
As for the very HN-ish "why don't you just go make XYZ?" retort, obviously it's because, like most of us (and unlike Elon Musk), I don't have the necessary truckloads of $100 bills necessary to make that happen. I'll get back to you after my windfall from selling PayPal...
I think the retort is coming from the fact that to do something amazing like building a reusable rocket (or other great, but easier projects) takes much more than money in the bank. It takes a whole lot of talented people working very hard for a long time. The leader of such people will need an amazing amount of dedication, work, skill, time, luck, drive, smarts, charisma, sacrifice, friends, money, charm etc. to pull it off. If the leader does not have a burning passion for the goal, giving up is the likely outcome with all the problems along the way. So when someone says that this person should be dedicated to some other goal, even though the one they are doing is great, that does not make any sense. The leader and the people working with him have a passion for a certain idea and the skills to work on towards that project. Those are not fungible to another project. Move Musk and all the people working at SpaceX to working on the Holodeck would just be useless and a waste.
Technology does not just progress by magic or money. People must do the hard work. The world is awash in capital at this moment with negative interest rates in some places. Physical resources (or money) is not the limitation for getting most new things done in the world at the moment. It is the complicated process of getting people working together, taking a million false steps, and not giving up before finally figuring out how to reach a goal.
I think we agree on one point: To do great things, access to capital is necessary but not sufficient. If all it took was hard work, I'm sure lots of us would quit our jobs today and get started!
True. Some start early. Elon Musk sold a video game he wrote called Blaster to a magazine when he was 12 years old for $500. Then he used that money to try to open a video arcade with his brother. He and his brother did get $28,000 to start Zip2 from his father, but that is not a huge sum. The cost of half a year of college. I would say, if you live in the US, access to capital is far down the list on what blocks people over the long haul.
I'd say 28K is a lot when it comes to a venture that may not pay off. I hear Elon's father was not particularly poor, so there is some leverage in that. Who knows if Elon could have made it otherwise without the capital. Makes me question if we all need some money to make money.
Curiously, what was the 28K spent on? Maybe 12K for rent, tops for 1995. He even lived in the office. Someone chime in?
Why not both? Lots of smart people working on both things any ways. I'd rather Elon focus on stuff that will iterate and get us off this planet in any case as he seems built for that.
Since he's focusing on that, why don't you go ahead and focus on making the holodeck. Thanks!
Musk said that the fuel (methane and oxygen) for Mars expeditions has to be produced on Mars, using solar panels, water and capturing carbon dioxide available in the atmosphere, and he also stated that the very same procedure could be used on Earth.
That doesn't mean it's anywhere close to being economical. It's just one of the few options they have there, or it's perhaps a little cheaper/more practical than carrying everything from Earth. Perhaps capturing it from Mars instead of bringing it from Earth means the project can cost "only" $5 billion per trip rather than $20 billion.
But that says absolutely nothing about doing that on Earth vs all the other much cheaper alternatives.
Sure, but the discussion was about energy and carbon footprint, not economics; I just reported what Elon Musk said the last presentation about how to produce the fuel starting from carbon dioxide.
Economic viability has to be proved, but I think they are more closer to it now than when they presented the BFR for the first time.
EDIT: I forgot the fact that CH4 is being burned, not released as-is in the atmosphere.
Original comment:
Carbon footprint is just one way of measuring the impact on climate, but that's only because CO2 is the biggest pollutant. However, methane (CH4) is much much much better in trapping heat. 19 times more potent over a 5 year period, or 4 times more over a 100 year period (source: http://www.onegreenplanet.org/animalsandnature/methane-vs-ca...).
This is despite having the same number of carbon. So technically the "carbon footprint" is zero if, as Elon said, you're extracting carbon from CO2 in the atmosphere, but if you change it to CH4, you're worsening by a big factor the impact on climate. Maybe over thousands of years that factor goes down to 1x but still...
All this is assuming you extract CH4 from atmosphere, which is extremely unlikely for economical reasons, as others have pointed out.
Burning CH4 has a lower footprint than it being freely in the atmosphere, so if they could capture it from the atmosphere and then burn it would be better.
sadly this is all I started thinking, but only because of how much he pushes EVs and Solar. It seems like a complete opposite move but given current technology there isn't a clean method to do what he wants.
I would be really curious how much works has gone into neutral fuels. pretty sure lox and such can be made neutrally with solar powered chillers but what is his other fuel? a hydrogen type would be similar would it not?
He mentions the possibility of making the fuel from solar power, water and CO2 on Earth in the same way he plans to for Mars. It wouldn't make economic sense now though. If you care about the environment that much, use the same process to make the same methane and run your ICE car off it. That's old tech.
Extrapolating very naively from SpaceX prices[1] for Falcon Heavy to low earth orbit suggests a ticket price of about $150,000, at $1500 per kg
That is ignoring safety, and other pros and cons such as Falcon Heavy didn't fly yet, Space-X doesn't have a passenger module, frequency and economic scale of passenger operation, different flight profile from LEO, lack of regulatory framework, and so on
Impressive if they achieve that. The price point they need to reach though for this to be feasible is business class. As suggested by the NY<->Shanghai route in the video, the major use for this would be distant business meetings that either have to be week long trips or video conferences. Instead they could be overnight or even day trips. Businesses have more buying power as well compared to consumers.
If they can maintain all ticket prices below $10,000 that would probably work. It would still be 2-3x what businesses normally pay, but they would arrive 10x faster, so it may be worth it at least for some. Musk just needs enough customers to make the business sustainable and so he can afford to build more such rockets and then keep dropping the price.
Business class isn't low enough. This thing has A380 passenger capacity and you can't fill an A380 with business class, there aren't enough rich people. You need economy.
Fuel cost is a constant for rocketry, there is nothing to figure out there, and people tend to go through a whole bunch of checks before they are allowed to be flown on a rocket to stop them from developing some critical issue in a place where there is no way to get help or be helped. You can't do emergency medical stuff while accelerating and decelerating in a rocket and this one is doing either one almost all the time.
Ah the total trip time is at most an hour. People have been stuck longer inside NYC subway. Also on most trans-atlantic flight emegency medical diversion can easily take more than an hour.
> Hey, I'm a bit overweight and I would be very much happy with the G's :).
Your head would be happy but your heart might disagree. If a good chunk of the passengers gets moved to the ER, happy but with heart issues I think it won't be very popular.
No, the current SpaceX rockets are ICBM enough. This is much harder - ICBM's don't need to land at ~0 m/s vertical speed, and if they carry nuclear warheads (are there conventional ICBMs at all?) they don't need ~1 m landing precision.
I know people have valid reasons to be skeptical about such projects. But maybe after 50 years or so when this kind of transport will be very common we will remember this day as one of the most historic events in the course of humanity.
And if it becomes that common, in 150 years time, New York will be under water. I remember reading that the instantaneous power output of one Apollo rocket taking off is roughly the equivalent of the entire average electricity load of the UK. Surely burning a country's worth of rocket fuel every time you want to travel long distance is not sustainable?
Well, New York City probably will be largely underwater in 150 years anyways, but not because of the BFRs. SpaceX plans to synthesize the fuel by using water, solar power and captured carbon dioxide from the earths athmosphere - just like it will be done on mars.
This was brought up in the presentation as well - they have plans to eventually use the same technology they will use on Mars, on Earth as well, to take CO2 out of the air and combine it with water to create methane and oxygen. If it happens, the rockets would be carbon-neutral.
And if it becomes that common, in 150 years time, New York will be under water.
If it becomes that common, it will be well within the major power's ability to block 1.5% of the sunlight that hits the Earth by posting sunshades at L1.
Surely burning a country's worth of rocket fuel every time you want to travel long distance is not sustainable?
It doesn't take that many airliner flights to match that power output.
Indeed, a Falcon 9 takes only the amount of fuel used by 2 long-distance 747 flights. BFR might be, say, five to seven times that, though it's a different fuel (natural gas instead of kerosene.)
Fusion power can't come soon enough. Maybe it's time for Musk to start working on that. He actually said in an older interview that he would like to tackle it eventually.
He recently said (paraphrasing) that it wasn’t particularly productive investing in Fusion when there’s a giant, very efficient fusion reactor in the sky. We’d be better off improving solar panel efficiency and energy storage solutions.
It won't make sense for most people for the first 30-50 years. That much is clear. However, it still has to make business sense from day one for some people. Otherwise the project is dead and forgotten, just like it happened to the Concorde.
They should really not put windows on this. At least not in the first models. Sure, passengers would love to see outside, but really it makes the design much more complicated for little benefit.
It can be stressful not to have any idea of what is happening outside, but you can simply alleviate that with external cameras and screens on board.
If this acctually happens, it would be interesting to see how the international law, ai<del><del>space trafic control and military missle defence systems develops, so that SpaceX can land one of these in Shangai without having to worry about accidentaly starting a thermonuclear war.
Musk seems to enjoy making promises about all kinds of fantasy transport, promising orders of magnitude cost reduction from already mature technologies like tunneling, rocketry, or high-speed rail. These promises meet with very little skepticism here.
It would be different if this was coming from the mouth of the Comcast CEO but it's coming from Musk who has a series of successful achievements of his own, a profitable space company with the worlds first re-usable rockets, the first company to successfuly market an electric car, fastest growing battery storage solution on the market. These things matter.
Those are great achievements but still nowhere close to the grandiosity of his vision. I appreciate that he is an accomplished person and CEO but that doesn't mean he's going to colonize Mars and give us instant transport between any two cities on Earth.
They have not delivered "orders of magnitude cost reduction from already mature technologies", which is what I said in my parent comment. They've instead made (valuable!) incremental advances, usually by relying on immense government subsidies.
What immense government subsidies did Tesla and SpaceX rely on? Tesla got a loan it paid back early and a $7k tax rebate per car for the first 200k cars which other car companies also got. SpaceX got a contract to build a rocket and capsule NASA wants to use, for a fraction of the price Boeing and Lockheed charge for same job.
"usually by relying on immense government subsidies" makes one think that Boeing and GM failed to do the engineering work that SpaceX and Tesla had done because they were somehow barred from some kind of government subsidy.
But of course, the opposite is true: Being, Lockheed, GM, Ford, etc. enjoy a lot of help from the government (money and regulation) and use a bunch of dirty tactics against Musk's companies. And despite this, SpaceX and Tesla did things the incumbents were incapable of doing. In some cases things that were said to be impossible rather than just uneconomical.
I think at least the "usually" in your post is unwarranted.
To be fair, you couldn't get a solar roof delivered in the next month like you could a traditional one.
From their site "Initial trial installations are complete and undergoing evaluation, customer installations are about to start and will ramp up through 2017."
Like the deck of an aircraft carrier? A specialized glider-reentry vehicle would allow the delivery of armored vehicles. It would also allow safer deployment of the rocket.
If I have to believe Elon, the fuel for the BFR is 'incredibly cheap' to produce. And the concorde flew over land and cities, a rocket goes straight up (for the first part) so noise problems should be acceptable.
In startups you often have tech that is more general than it needs to be, and you start thinking about all the opportunities, but it can be a mistake. In your go-to-market strategy, you need focus. If you say, "We have 3 business models", it means you don't yet have a business model.
I hope Elon the best, but I wonder if that is happening here. SpaceX is going to sell Internet, do fast air travel, do space tourism, . . . . Same with Tesla: we aren't just a car company, we're a battery company! There is a hyperloop and a digging company and solar rooftops. I think it's true there are many opportunities, and history has had its conglomerates like GE, but there is risk in losing your focus.
In your go-to-market strategy, you need focus. If you say, "We have 3 business models", it means you don't yet have a business model.
It's pretty clear that SpaceX is in the reusable rocket business. By your logic, Boeing didn't have focus, because they built seaplanes, flying boats, fighters, cargo planes, and passenger planes. (This is what they did, in the order that they did it.) They apparently had at least 5 business models. Whoops. I guess they didn't have a business model!
These are all related to the core business though. If you can launch rockets, you can launch sats. If you can discount sat launches, you can launch a lot of sats.
If you can launch rockets capable of re-entry and reuse and need to finance building rockets to go to Mars, you can build rockets for cross-continental travel.
It's not like SpaceX is building a smartphone. They're building in their core competencies.
It's not like people will be able to reach their destination within an hour of booking their ticket. These flights will probably occur once or twice a day, which kind of defeats the purpose?
Regular intercontinental flights have the same problem. With transport this fast, you could theoretically fly in the morning, have a full day of meetings, and be home by the evening. With regular flights you'd spend a full day traveling both ways
What about pollution? Rockets seem to waste much more fuel compared to a plan on an equivalent distance, though I might be wrong and the main burn would consume less overall.
I think this is amazing - but what are the military implications? I mean, the military-industrial complex is not likely to stand by and watch this capability become so commonplace that it invalidates the purpose of having fast-attack forces at the readiness.
I mean, I guess the answer is pretty clear: the US Military will be the first customer for the BFR, before any transportation companies get it .. they already hold technology in reserve for their war-fighting abilities, so .. its going to be interesting to see what the MIC version of this is going to be .. assuming they don't already have it. (Some people think they do ..)
SpaceShipTwo is a very much suborbital craft that would only have a range of a few hundred (maybe a thousand?) miles if used for travel. You'd have to build something much bigger to do antipodal travel like this.
The capability you need to go suborbital from one side of the Earth to the other is essentially the same as what's needed to go into orbit. (Thus all the ICBMs that got repurposed as orbital launchers.) Any vehicle that can't reach orbit probably can't do what BFR could do.
Doesn't have to be carbon neutral; just has to be better, or not much worse, than whatever alternative transportation you'd use to get to your destination.
Like the security precautions at airports? Any airport that I'm familiar with has access roads and roads around it that are accessible to the public from where any idiot with an RPG or possibly even a rifle could attempt to bring down a passenger jet. And yet it does not happen.
roads around it that are accessible to the public from where any idiot with an RPG or possibly even a rifle could attempt to bring down a passenger jet. And yet it does not happen.
It's so unlikely to work, that it would just be a means of getting yourself arrested. If rifles and RPGs were any good at bringing down planes, armies wouldn't need specialized AA. (They are pretty effective against landing helicopters, however.) Don't get me wrong. If you hit it at the right time and place, it would be destroyed. That's not nearly as easy as one might think.
Specialized AA weapons are another story, however. Then the problem becomes getting your hands on one.
The Tom Clancy-esque plot might involve a modern sniper rifle fired from a custom made gyro-stabilized platform. The low rent version might involve some drones supplying realtime crosswind data. Alternatively, there might be a guided 0.50 cal bullet. http://www.cnn.com/2015/04/29/us/us-military-self-guided-bul...
'SAM-PRAS is a unique market-leading solution used by counter-terrorism agencies to identify potential MANPADS launch points within range of flight paths.'
I don't work for or have any association with this company BTW, just aware of their software.
>Great policing, or do the bad guys just lack imagination?
Ease.
It is likely quite difficult to get an RPG without getting eyes on you, then driving to an airport with an RPG, then lining up a shot and hoping to hit a plane moving at 100+ MPH.
Or you can take a truck and drive it through a crowded mall.
It's not even about the latency issue, in most cases.
Today the biggest problem with, specifically, trans-pacific flights is that you burn an entire day in travel, both ways. That means if you want to take a weekend to go somewhere, you can't, because 2 days minus 2 days is zero days, you have no time to actually spend doing anything. And that's aside from the recovery time of that much air travel. Short duration trips are then only reasonable if you can cram in some very high priority activity, which is very limiting. For shorter trip times it becomes feasible to squeeze in short trips on a more regular basis. I had a coworker who lived in the Seattle area and flew down to LA every weekend to visit his wife for several months. That's only feasible if you can cram travel into Friday/Sunday evenings. That sort of thing will become possible with a service like BFREE.
Most importantly, you don't burn entire days in travel, you simply add travel as a component into those days. These flights are expected to be in the $10k range, so basically anyone who makes more than about $4m a year will have a straight up logical cost/benefit reason to use BFREE for long distance flights instead of air travel, because it means they get the majority of that whole day back, instead of burning it flying.
Industrial (Oil/Gas/Materials) repairmen. You're talking a few 100,000 for every hour they're not pushing product. These places are located at the resource, not where employees are so you're likely going to need to fly someone super specialized in the maintenance of this one item half way across the globe.
Histories of financial crises include a fair bit of catching Concorde between London and New York. That's the only case I can think of that's urgent and serious enough to justify face-to-face talks where it's safe enough to have an unplanned international visit.
Marketing of that product is awesome. But does it scale? Very unlikely! That's great to have impossible goals to make people dream, but stop bullshitting people saying it will replace commercial airplanes and everybody will be an astronaut for the same price.
Why is the Concorde not in service anymore? Simple: it was a very little market, over-polluting for over-privileged and we do not need that to enhance traveling, we already tried! How would this BFR be different?
The Concorde was one airplane. Its not like we have tried every possible way of increasing travel speed.
They will build this rocket anyway, the will have to make it reusable anyway. All they did is consider using it as a transporter for people on earth.
Its just one way the can potentially make money with this technology. Does not hurt to try. No reason to shit on the idea and claim its some absurd fantasy.
Musk didn't say it would replace regular planes nor we would all be astronauts, that's just you saying it. Also, his talk was about 43min long and only the very last "slide" and couple of minutes discussed the why-nots of reusing BFR for local transportation, because technically it is possible.
Well I just watched the video, it clearly imagine a world where you could fly BFR like airplanes... I don't see how it would be accessible to the mass, therefore it's a niche product for the very rich, no big deal!
It didn't shut down because the passengers were too privileged nor because it was too polluting. What's next to go? Ferrari and Rolls Royce hit all your criteria for a transport failure too.
Looks like fun. I'd love to see the in-flight safety video!
"Make sure there's nothing in your pockets because we'll be hitting 3 Gees. If anything goes wrong, we're all probably toast."
I think this was just an interesting idea thrown out at the end of a talk that had much more interesting stuff, such as redirecting all of SpaceX's resources away from Falcon to build the BFR, and putting humans on Mars by a 2024 'aspirational goal'