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SpaceX BFR [video]

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Re: SpaceX BFR [video]

#41

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.

Re: SpaceX BFR [video]

#44

Earlier quoted context omitted.

I trust SpaceX to figure this out. They've already solved the hardest problem: landing a rocket upright

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 t…

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.

Re: SpaceX BFR [video]

#45

can anyone think of scenarios where somebody has to be somewhere in an hour? what about making one of those the new airforce one?

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.

Re: SpaceX BFR [video]

#46
post #42

I'm guessing there would be some environmental impact? It can't exactly be carbon neutral burning all that fuel?

It can be if the fuel is synthesized from carbon dioxide in the atmosphere with solar as a power source.

Re: SpaceX BFR [video]

#47
post #3

Earlier quoted context omitted.

Hey, I'm a bit overweight and I would be very much happy with the G's :). That said, I think those are the two primary issues. Airplanes, cars and trains can break on you, but they generally won't explode .

> 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.

Well, you just ruined my day. But probably saved my life, so thanks. :(.

:).

Re: SpaceX BFR [video]

#48

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…

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.

Re: SpaceX BFR [video]

#49
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.
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