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Comment by aphextron | Hacker News Reader

Rocket based travel will never ever ever happen on a widespread scale simply because of the G forces involved. Passengers on an airliner will begin feeling uncomfortable at around 1.2 G's and > 20 degrees of bank angle. The thought of subjecting regular paying passengers to 3+ G's and a full 360 degrees of pitch/roll is absurd. It could definitely be a niche thing for people that are physically fit, but this just isn't the way to go for high speed transportation. More traditional airframes and scramjets are far more likely to make hypersonic travel a reality.

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20 minutes of discomfort to save 12+ hours of flight time? Sounds worth it to me.

Sure, but will your grandma say the same? My point is that this will never be a normal every day thing for the masses like air travel today.

True, but I don't think BFR is ever meant for the masses. And airplanes, which are gentle but can be uncomfortable, are barely for the masses (in 2015 only 45% of Americans flew on a plane).

https://www.forbes.com/sites/danielreed/2016/04/14/americans...

...only? that's a first world problem if i've ever seen one :)

haha well I meant only 45% of the population isn't really "the masses"

I'd argue that it is, that's almost half the total population and an even larger percentage of working age adults.

How many of that 45% took a first class or business class international flight?

My grandma isn't travelling on a plane 12 hrs to anywhere. Long haul travel is more for the youngish anyway (think baby boomers). And my parents would take a 30 minute roller coaster over a 12 hr flight even if that meant using a puke bag every time.

At the price point, I imagine it won't be as competitive as a business class fare, which 99% of people will choose over 30 mins of non-stop barfing. No?

If you can bear with modern air travel today, the process, the rush, the waiting, the hassle with luggage, and worst of all being cramped in little seats with hundreds of other people around for really long periods of time, then I think you will probably be able to handle the rocket. The devil is in the details though.

Regardless, not only do I think I would I appreciate the shorter, more violent flight more as I got older, I would also appreciate the roll of the dice that if anything goes wrong we just all die instantly. Not a bad way to go, really.

Ever been bobsledding? I question how well even a fit adult deals with G forces that high. I consider myself pretty fit, but I found my experience at 4Gs to be completely unexpected. I could barely keep my head out of my lap. Sure, it was fun, and I didn't die, but they would not let the elderly, those with spinal injuries, or pregnant women ride a bobsled even for 90 seconds.

To that I would say the G-force strength and direction should be predictable, known even when they are designing the seats before building the rocket. So the passengers should be in an optimal position where they don't need to hold up their heads against the Gs but are cradled by the seat. I think that is very different from the bobsled analogy where the G-forces are changing intensity and direction all the time and you are not in an optimal position.

If the G-forces are unpredictable, well something went really really wrong.

But you are probably right in that there will be more medical restrictions than there are now. But someone with a spinal injury, or who is very pregnant, or very weak from age probably isn't going to be flying in today's aircraft either.

> we just all die instantly

It's surprising (to me at least) that it's not always instant. For example on the space shuttle Columbia, the astronauts went unconscious after a few seconds as the spacecraft was tumbling and breaking apart [1] but it's plausible that they could have regained consciousness if they survived the violent episode inside the shuttle as it broke apart.

1. https://www.nytimes.com/2008/12/31/science/space/31NASA.html

Normal people won't be able to afford this. It will serve a small market of wealthy, willing, healthy people.

Don’t underestimate the discomfort of spending a dozen hours in economy class. I’d take the rocket ride every day and twice on Sunday over that, and I’m not terribly fond of crazy rides.

I'm guessing C-levels are going to start getting into shape if they have 20+ less hours on planes during their day.

You seem to underestimate how annoying modern air travel is, at least in America. One has to stand in at least 3 different lines (baggage, security, boarding) before getting on the plane. Whether in the terminal or on the aircraft, the seating feels like it was designed to be as uncomfortable as possible.

I imagine that there will be people willing to travel via rocket just because of the 3+ G's. And I'd take a 30 minute roller coaster ride over a 10 hr first class flight any time, all the time. Less time spent flying > comfort while flying. One immediate benefit is that one doesn't have to take a week or more off of work for intercontinental travel. Weekend jaunts to Pattaya or the Alps are possible when you aren't spending 20+ hours in transit.

I wonder if 3G's while lying on your back on a gel cushion isn't a lot easier to take than 3G's standing on your feet?

It certainly is more comfortable; is it more comfortable enough? I'm betting a lot of people would be fine with it.

> a full 360 degrees of pitch/roll

Can't this be somewhat alleviated with some sort of free 360 deg. rotating suspension of the passenger cabin? So that the G forces are at least pointing "down".

This may be a stupid question, but could people be put under for 30 minutes and just be woken up at landing?

So you'd need a licensed anesthesiologist monitoring every passenger? Sounds expensive.

It's a matter of monitoring and dosage. You can easily do mass scale sedation with proper monitoring and appropriate patient selection. If your BMI is over 25 or you have OSA, you wouldn't qualify. If you're healthy, fit, and consenting, you could be sedated for a long haul flight and have minimal hangover, perhaps even feeling rested.

No. General anesthesia is a risky procedure, requiring constant one-on-one monitoring by a anesthesiologist.

Sounds like an industry ready for disruption. If only these damn regulations weren't holding us back.

/s (sort of).

GE has been trying to disrupt anesthesia for quite some time:

http://www3.gehealthcare.com/en/products/categories/anesthes...

Edit: Since its not obvious, they have some machines that can go in autonomous mode and alert the hospital if the patient needs an actual doctor to fix something.

Can you show me a GE product which doesn't need an anesthesiologist present at all times?

As far as I can tell, none of those devices acts autonomously or even close to it.

If John Glenn could do a Shuttle flight at 77, I suspect you're overstating the difficulties here. People voluntarily subject themselves to 3+ Gs and 360 degrees pitch/roll at amusement parks daily, with fairly minimal levels of physical fitness being required.

You know John Glenn's name precisely because he is exceptional. I would certainly choose the discomfort of a 2-minute roller coaster over the discomfort of a 2-hour commercial flight, but... a man who set milestones in American spaceflight and was trained by NASA for a shuttle mission is hardly the baseline.

John Glenn is an exceptional case however. His career was in rocket travel and experimental aircraft.

If the full 30 minute flight is like a roller coaster, I would be green by the time we got there and probably have a full puke bag. But I'd still prefer that to a 12 hr long haul flight in coach.

If you could afford flying on a rocket, I bet you can also afford flying first-class. Would that alter your preference?

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