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by qayxc 2022 days ago
Except totally unreasonable :)

Rockets that size cannot be launched anywhere near populated areas, so they'd have to launch from off-shore platforms; outside of Australia, USA and Russia there are no worthwhile destinations that can safely host on-shore rocket launch complexes for that class of rocket.

This poses quite complex logistical challenges that enthusiasts just love to handwave away. But there's even more to it: airspace needs to be closed on both launch and target sites.

Weather will lead to scrubbed flights as rockets have much tighter weather parameters than aeroplanes and are incapable of changing routes mid flight or divert to alternate airfields.

The most ridiculous part, however, is passenger logistics: every astronaut/cosmonaut/taikonaut wears pressure suits during ascend, since otherwise there's no way to breathe in case of a loss of cabin pressure once you're above 20km. Oxygen masks just won't do anymore at such heights. This means passengers would need to wear and familiarise themselves with pressure suits, unless SpaceX can convince the FAA somehow that even fewer failure modes can be mitigated while still being safe for passengers...

Getting onto the rocket is another point that's far from trivial - one doesn't simply walk into Starship and pick a seat. The seats wouldn't be upright, so passengers would need to climb into them and be secured by personell. Not to mention the elevator ride and the long wait during fuelling (remember: SpaceX are the only ones who do "dry-loading", that is they only start fuelling once the passengers are on board).

So your 30 minute short trip from LA to Paris would in reality consist of a 1 hour drive to the port, followed by 1 hour check-in and a 1 hour boat ride to the off-shore launch facilities. Next you'd have at least 1 hour of boarding procedures (limited elevator space, pressure suit fitting, seating) followed by fuelling (maybe another hour?). So after about 5 hours or so you are finally clear for launch and arrive somewhere off the coast of France 30 minutes later. From there it's another hour for unloading, an hour to get to the coast and another two hours from the coast to Paris.

In total, best-case scenario travel time would be about 9½h - better than the 16h via plane (12h flight + 4h getting to-/from airport plus boarding time), but a far cry from Shotwell's "business meeting in Abu Dhabi in the morning and back in Vancouver for dinner".

The off-shore launch platform idea isn't mine, by the way - the concept was brought forward by SpaceX themselves and presented by Glenn Shotwell who said "the longest part of the ride is be the boat out and back" [1].

I'm highly sceptical of the idea - not because I think it's impossible, which it isn't - but because the logistics, regulatory conditions, and economics behind it just don't make sense. I could be wrong, of course, and stranger things happened, but realistically, the odds are very much against this ever going to happen[+].

[+] using Starship/Super Heavy as envisioned and developed today

[1] https://www.youtube.com/watch?v=Dar8P3r7GYA&feature=youtu.be...

3 comments

> would in reality consist of a 1 hour drive to the port, followed by 1 hour check-in and a 1 hour boat ride to the off-shore launch facilities. Next you'd have at least 1 hour of boarding procedures (limited elevator space, pressure suit fitting, seating) followed by fuelling (maybe another hour?). So after about 5 hours or so you are finally clear for launch

I see that the TSA mindflayers have not been kind to you. Many of those steps do not have to be performed sequentially. For example check-in and suit-up could be performed on the ferry. And if you're already throwing stupendous amounts of money at travel then you also don't have to pick a slow ferry, consider jet hydrofoils. And you don't even have to start at some port far from a city. If the city has a major river it could take up passengers in the middle of the city, travel down the river and on towards the launch platform. And if we're talking about strapping hundreds of people onto rockets then the safety margins on everything would have to be improved far enough that the dry-loading probably is not needed anymore either.

As far as logistics go it seems hard but possible. But you may be right that regulatory conditions could prove prohibitive since not everyone will just go along with musk's plans.

The ferry doesn't deliver individuals. It carries a passenger seating/baggage module. People get themselves strapped in on the way out. At the launch site the module is hoisted and locked into the vehicle. On arrival, the module is extracted and lowered to the boat deck. People come down to the deck during the boat ride.

Probably their "pressure suits" are the same as the seats, just clamshells with room to scratch, and (often enough) barf.

But scheduled passenger service is 15-20 years off, if ever. They only talk about it now to make the whole enterprise seem inclusive, and not just billionaire playtime. It's even money that civilization will collapse, first.

We're still talking about international flights here - 90 min pre-flight arrival on international flights is standard. There won't be any less rigorous security checks because you're flying a rocket.

Parallel procedures might sound fine in theory, but it's way simpler to just have people onboard the ferry who are good to go and don't need to be kept there, make a scene, etc. Security personell and access to information systems is much simpler to come by in the port, which incidentally already has customs facilities anyway.

> And you don't even have to start at some port far from a city.

Yes you do, that's the whole idea of safe distances with rocket launches. We're talking about a vehicle that basically can be as devastating as a small tactical nuke in terms of destructive potential. Especially during launch, you'd want that thing as far away from densely populated areas as possible: https://www.youtube.com/watch?v=gklVhRzkVqA&feature=youtu.be... that's what happened last time a 30-engine rocket failed...

> consider jet hydrofoils

That might be an option, but then again even Shotwell explicitly mentioned the boat ride to be longer than the 30 min rocket ride even at just 10 miles out, so I don't think fast ferries are the most realistic option (mostly for safety reasons).

> > And you don't even have to start at some port far from a city.

> Yes you do, that's the whole idea of safe distances with rocket launches.

I meant the old-fashioned, boaty port, not space port.

Ah, I see, sorry - misunderstanding on my part :)
Commercial aircraft were also totally unreasonable for quite a time after Wright's first flight in 1903.

Musk has explicitly stated that a "safety first" attitude does not get people to Mars. His hierarchy of action is "don't panic", not yet specified, "safety third, maybe". This philosophy is hard to implement in modern day America, but the attitude is part of what allows Elon Musk and the people that work with him to do what they do.

> Commercial aircraft were also totally unreasonable for quite a time after Wright's first flight in 1903.

That's comparing apples and orangutans.

This isn't a 1903 situation at all - we've launched rockets on a weekly basis for 60 years and operated crewed reusable spacecraft for more than 30 years.

This is well known territory. All limitations, possibilities and risks are well known and documented.

If you have to make a comparison, choose the Concorde versus Ju-52 or something. But even that's flawed because it doesn't fit at all.

The concerns I mentioned aren't going to magically disappear - even a "perfectly safe" (by whatever definition) rocket still has to deal with these. A 30-engine, 122m, 65MN rocket will generate a literally deafening blast and for that reason alone cannot be launched near cities. This is a fact of nature, not just a simple engineering problem or overly cautious safety concern.

Same goes for airspace closure, weather on both ends, and simple things like customs and security checks.

Starship won't have any cross-range capabilities, full stop. That's how rockets work and one consequence of this is that bad weather means a scrubbed launch, simple as that. Nothing to do with attitude or "modern America".

That's just physics and natural phenomena that exist and cannot be wished away.

Again, none of this prevents point-to-point travel from being possible, it just demonstrates that it's likely not going to be an everyday occurrence like long-haul flights. A novelty, maybe. Another option for the rich and important, sure.

A viable alternative to regular jets, I think not. Time might prove me wrong, but I'm fairly certain the odds are stacked against regular point-to-point passenger flight service using huge rockets.

>Weather will lead to scrubbed flights as rockets have much tighter weather parameters than aeroplanes and are incapable of changing routes mid flight or divert to alternate airfields.

This part is not true. Weather plays a significant role for thin rockets. This one is thick enough to be launched during usual weather fluctuations. Of course, a tornado or cyclone might be disruptive, but that's also true for normal airplanes.

> This part is not true.

Yes it is. A wider rocket has more generous margins when it comes to wind, sure, but thunderstorms, heavy rain, storm with strong gusts (doesn't have to be extreme either), sudden ice, heavy snow, etc. etc. will still prevent launches and especially landings.

> Of course, a tornado or cyclone might be disruptive, but that's also true for normal airplanes.

Normal aeroplanes fly around unfavourable regularly and flying holding patterns is normal procedure anyway. None of that is possible with rockets, no matter how wide.

The situation is worsened by the fact that pilots have the luxury of time when planning their route, e.g. bad weather at the destination during launch isn't a big deal for long-haul flights, since there's often 10 hours or more until it even becomes relevant.

With a rocket, weather at the launch and target site have to be favourable at pretty much the same time, since you'd get there in well under an hour.

We'll see later today how well the aerodynamics might work and how the rocket behaves. I remain very sceptical about the point-to-point idea.